1. health and fitness
2. disease
3. cancer

B
Scientific Sessions
(SS)
Friday ....................... 139
Saturday................... 197
Sunday ..................... 243
Monday .................... 271
Tuesday.................... 303
S137
Scientific Sessions
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S139
Friday
Friday, March 6
Scientific Sessions
room A
2nd level
room B
2nd level
room C
2nd level
room E1
entr. level
room E2
entr. level
room F1
entr. level
room F2
entr. level
room G/H
lower level
room I
lower level
room K
lower level
07:00
07:00
07:30
07:30
08:00
08:00
08:30
CC 117
Cardiac
Imaging
Radiological
anatomy
and normal
variants
revisited
(p. 8)
09:00
09:30
CC 116
Spinal
Imaging and
Intervention
6SLQDOEDVLFV
Classics and
news
(p. 8)
SF 1a
Special
Focus
Session
Assessment
of tumor
response
(p. 9)
E³ 120a
Foundation
Course:
Imaging of
the Urinary
Tract
([DPLQDWLRQ
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(p. 10)
E³ 120b
Interactive
Teaching
Session
Imaging in
common
clinical
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tissue tumors
(p. 10)
08:30
SF 1b
Special
Focus
Session
Prostate
cancer
(p. 11)
RC 111
Neuro
Basic MRI
(p. 11)
RC 115
Vascular
Aortic imaging
strategies
(p. 12)
RC 105
Computer
Applications
:KDWFDQ
PACS do
today?
(p. 13)
10:00
10:30
SS 210
Musculoskeletal
Tumors and
ERQHPDUURZ
(p. 142)
11:00
11:30
SS 201a
GI Tract
Gastrointestinal
cancer:
Detection
and treatment
response
(p. 144)
SS 206
Contrast
Media
New
perspectives
in contrastHQKDQFHG
imaging
(p. 146)
E³ 220
SS 207
Foundation
Genitourinary
Course:
Uterus and
Imaging of
ovaries:
the Urinary
MDCT and
Tract
MR studies
Getting started
(p. 148)
(p. 17)
SS 202
Breast
New
developments
on digital
systems
LQEUHDVW
diagnosis
(p. 150)
SS 208
Head and
Neck
1HUYHVWHHWK
eyes and ears
(p. 153)
SS 215
Vascular
Vessel wall,
SODTXH
imaging and
MRA
(p. 155)
SS 205
Computer
Applications
CAD, image
registration
and
segmentation
(p. 157)
12:00
11:00
11:30
12:00
Opening Ceremony/
Presentation of
Honorary Members
and Gold Medal
Awards
12:30
12:30
Opening Lecture
13:00
13:00
(p. 18)
13:30
13:30
14:00
SS 301a
Abdominal
Viscera
Liver: MR
diffusion and
spectroscopy
(p. 169)
14:30
15:00
SS 310
Musculoskeletal
$UWKULWLV
(p. 171)
SS 301b
GI Tract
CT
FRORQRJUDSK\
(p. 173)
SY 1
Bayer
Schering
Pharma
Satellite
Symposium
(p. 522)
E³ 320
Foundation
Course:
Imaging of
the Urinary
Tract
Vascular and
LQÀDPPDWRU\
disease
(p. 18)
14:00
SS 307
Genitourinary
SS 302
Kidney:
Breast
0RUSKRORJLFDO Screening and
and functional
diagnosis
studies
(p. 177)
(p. 175)
SS 308
Head and
Neck
New
WHFKQLTXHV
in tumor
management
(p. 179)
SS 315
Vascular
Magnetic
resonance
DQJLRJUDSK\
(p. 181)
SS 305
Computer
Applications
New trends
in PACS and
workstations
(p. 184)
15:30
14:30
15:00
15:30
16:00
CC 416
Spinal
Imaging and
Intervention
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16:30
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registration
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Dual energy
computed
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CC 418
Breast: From
Basics to
Advanced
Imaging
From
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EUHDVWLPDJLQJ
(p. 20)
E³ 420a
Foundation
Course:
Imaging of
the Urinary
Tract
Renal masses
(p. 21)
E³ 420b
Interactive
Teaching
Sessions
Prostate
cancer:
Diagnosis,
staging and
follow-up
(p. 21)
RC 402
Breast
&KDQJLQJ
DSSURDFKHV
WREUHDVW
diseases?
(p. 21)
SF 4b
Special
Focus
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Neurodegenerative
movement
disorders:
Practical guide
(p. 22)
16:00
RC 415
Vascular
Occlusive
disease of
WKHYLVFHUDO
arteries
(p. 23)
RC 405
Computer
Applications
PACS in
evolution
(p. 24)
16:30
17:00
17:30
18:00
18:30
19:00
S140
09:30
10:00
10:30
18:30
09:00
19:00
A
B
C
D
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F
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F
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Scientific Sessions
room L/M
1st level
room N/O
1st level
room P
1st level
room Q
2nd level
room R
1st level
room U
2nd level
room W
2nd level
room X
1st level
room Y
2nd level
room Z
2nd level
07:00
07:30
07:30
08:00
08:00
08:30
09:00
09:30
08:30
MC 125
Extremity
Joint MRI
Upper
H[WUHPLW\
Anatomy,
variants and
pitfalls
(p. 14)
MC 119
Advances in
CT and MRI in
Major Trauma
Head and neck
trauma
(p. 14)
RC 104
Chest
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carcinoma
(p. 15)
RC 101
Abdominal and
RC 108
Gastrointestinal
Head and Neck
(VRSKDJHDO
6NXOOEDVH
cancer: Modern
(p. 16)
imaging
(p. 16)
09:00
09:30
10:00
10:00
10:30
11:00
11:30
10:30
SS 211
Neuro
Diffusion tensor
imaging
(p. 159)
SS 201b
Abdominal
Viscera
Liver:
Hepatocellular
carcinoma
(p. 161)
SS 204
Chest
Pulmonary
nodule
detection and
evaluation
(p. 163)
SS 209
Interventional
Radiology
8SSHUERG\
interventions
(p. 165)
SS 203
Cardiac
Coronary CT
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Reconstruction
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dose reduction
(p. 167)
WS 223
Cardiac
CT PostProcessing
and Analysis
Hands-on
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WS 222
Experience
Vascular
Procedures
Using
Simulators
11:00
11:30
12:00
12:00
12:30
12:30
13:00
13:00
13:30
13:30
14:00
14:00
14:30
15:00
SS 311
Neuro
Functional
magnetic
resonance
imaging
(p. 186)
SS 306
Molecular
Imaging
Preclinical
applications
(p. 188)
SS 304
Chest
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(p. 190)
SS 309
SS 303
Interventional
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Radiology
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interventions
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WS 322
Experience
Vascular
Procedures
Using
Simulators
ELGA
(Electronic
health record)
(p. 136)
WS 323
Cardiac
CT PostProcessing
and Analysis
15:00
15:30
15:30
16:00
16:00
16:30
17:00
14:30
MC 425
Extremity
Joint MRI
Lower
H[WUHPLW\
Anatomy,
variants and
pitfalls
(p. 25)
RC 408
Head and Neck
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neck
(p. 25)
RC 403
Cardiac
Tips and tricks
to improve your
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(p. 26)
RC 409
Interventional
Radiology
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patient
(p. 27)
RC 401
Abdominal and
Gastrointestinal
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(p. 27)
16:30
17:00
17:30
17:30
18:00
18:00
18:30
18:30
19:00
19:00
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S141
Friday
07:00
Scientific Sessions
10:30 - 12:00
Room B
SS 210
Tumors and bone marrow
Moderators:
K. Bohndorf; Augsburg/DE
P.R. Kornaat; Leiden/NL
10:30
The value of proton magnetic resonance spectroscopy and diffusionweighted imaging in the differential diagnosis of musculoskeletal tumors
X. Lin, J. Xue, J. Cao; Jinan/CN (linxt@sdu.edu.cn)
Purpose: The apparent diffusion coefficient (ADC) and the content of lipid (Lip),
choline (Cho) and creatine (Cr) of musculoskeletal tumors vary in different pathologic
lesions. This study was carried out to evaluate the value of ADC and Lip/(Cho +
Cr) in the differential diagnosis of musculoskeletal lesions and to determine the
relation between ADC and Cho/Cr ratio.
Methods and Materials: A total of 52 patients with musculoskeletal tumors, 28
malignant and 24 benign confirmed by histology, were examined on a 1.5-T MR
scanner. Diffusion-weighted image (DWI) and 1H-MRS sequences were performed.
Quantitative analysis was performed using region of interest (ROI) measurements
and calculation of a bone marrow. Peaks of Cho, Cr and Lip were observed in 1HMRS, and the ADCs of the tumors were calculated using three different b values,
0, 300 and 600 s/mm2. The correlation between tumor ADCs and Cho/Cr was
analyzed by Pearson correlation test.
Results: ADCs in benign tumors were significantly higher than those of malignant
tumors (P .001). The Lip/(Cho+Cr) in benign tumors were significantly higher
than those of malignant tumors (P .001). The chemical shift of the lipid peak is
between 1.5-2.09 ppm. There was an inverse correlation between ADC and Cho/
Cr (r=0.426, P 0.01)
Conclusion: ADC and Lip/(Cho+Cr) are useful in the differential diagnosis of
benign and malignant musculoskeletal tumors. Tumor ADC correlates inversely
with tumor Cho/Cr. DWI is sensitive and 1H-MRS is reliable in the diagnosis of
musculoskeletal tumors. Combined use of ADC and 1H-MRS will enhance the
diagnostic accuracy accordingly.
B-002
10:39
Diagnostic impact of echo planar diffusion-weighted magnetic resonance
imaging (DWI) in characterization of musculoskeletal soft tissue masses
using apparent diffusion coefficient (ADC) mapping as a quantitative
assessment tool
R. Warda, A. EL Sherief, K. Batterjee; Jeddah/SA (radywarda2002@hotmail.com)
Purpose: To elicit the diagnostic impact of echo planar DW imaging in distinguishing
benign from malignant musculoskeletal soft tissue masses using ADC mapping as
a quantitative assessment tool.
Methods and Materials: The study included forty-two patients presented with
musculoskeletal soft tissue masses according to clinical or previous imaging findings. Echo Planar DW imaging using diffusion gradient strengths yielding b-values
(0, 250, 500 and 1000 seconds/mm2) were performed in addition to standard MR
protocols. MR imaging data were analyzed regarding the location, signal intensity
changes and pattern of enhancement of the lesion. The ADCs of the lesions were
calculated and compared with the histopathological findings.
Results: Histopathological findings revealed 22 benign lesions. On other hand, 20
malignant tumors were proved. The mean ADC value of all benign soft lesions was
1.76 p0.24 while that of all malignant lesions was 1.21p0.18. For benign lesions,
the highest ADC value was seen in ganglion (2.9 p 0.43), while the lowest one was
seen in aggressive fibromatosis (0.35 p0.04). For malignant lesions, the highest
ADC value was seen in liposarcoma (1.8p0.25), the lowest ADC value was seen
in fibrosarcoma (0.9p0.16).
Conclusion: ADC measurement of soft tissue masses is promising as a noninvasive
tool in differentiation of benign and malignant soft tissue lesions, providing additional
information in characterizing the soft tissue masses but do not replace the routine
MRI sequences. Further prospective studies with larger scale of patient populations
using optimized diffusion imaging sequences may be required.
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10:48
Value of 4D-MR angiography in the evaluation of soft tissue tumors
S. Lecocq, M. Louis, C. Baumann, T. Batch, R. Detreille, D. Roch, A. Blum;
Nancy/FR (sophielecocq@gmail.com)
Musculoskeletal
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B-003
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Purpose: To evaluate the performance of 4D-MRA in the staging and grading of
soft-tissue tumors.
Methods and Materials: Fifty-nine soft-tissue masses underwent classic and
dynamic contrast material-enhanced with 4D-MRA (TRICKS®, GE) MR imaging. Diagnosis was based on histologic findings (n=39) or results of all imaging
procedures with clinical follow-up of at least 6 months (n=20). Two independent
reviewers evaluated the dimensions, location (compartment), vascular and nervous
invasions, and dynamic enhancement of the tumors. The degree of interobserver
and intertechnique agreements was calculated. A univariate and multivariate logistic regression analysis was used to identify the TRICKS parameters that might
be predictive of malignancy.
Results: The interobserver and intertechnique agreements were good or excellent
for all the parameters except for the analysis of liquefaction. The most discriminating parameters to predict malignancy were the peripheral enhancement, the
type 5 of time intensity curve and a short time to peak of the tumor. The TRICKS
sequence had a very high accuracy in the detection of vascular invasion, but due
to the low prevalence of this sign, this finding was of relatively low value to predict
malignancy.
Conclusion: TRICKS should be added to standard MRI for pre-therapeutic evaluation of soft tissue tumors when vascular invasion is suspected.
B-004
10:57
MR imaging features of skeletal muscle lymphoma
C. Chun, W.-H. Jee, H. Park, S.-H. Lee, Y. Kim, J.-M. Park, S.-H. Park; Seoul/KR
Purpose: To describe the findings of MR imaging of skeletal muscle lymphoma.
Methods and Materials: The MR images of pathologically proven lymphoma of
the skeletal muscle were analyzed for patterns of muscle abnormal signal and
contrast enhancement, relative preservation of intramuscular fat planes, fascia
involvement pattern, and subcutaneous and skin abnormalities. Six patients with
direct extension from lymphoma of bone were excluded.
Results: There were nine patients with primary muscle lymphoma and eight
patients with muscle metastasis from systemic lymphoma. Skeletal muscle lymphoma presented as an intramuscular mass in 11 cases (65%) or muscle abnormal signal in 6 cases (35%). Extensive adjacent abnormal signal was observed
in eight patients (73%) with intramuscular mass. Muscle enlargement and some
remaining intramuscular fat planes were observed in all cases. A total of 14 (82%)
cases showed traversing vessels within muscle involvement. All lesions showed
intermediate signal on T1-weighted images. On T2-weighted images, all lesions
showed intermediate signal with diffuse involvement, except for one patient with
predominantly peripheral thick band-like abnormal signal in the muscles. Among the
contrast-enhanced T1-weighted imaging of 16 patients, skeletal muscle lymphoma
showed diffuse enhancement in 10 patients (63%), predominantly peripheral thick
band-like enhancement in 4 patients (25%) and marginal septal enhancement in
2 patients (13%). Thick irregular enhancement of deep fascia or superficial fascia
was observed in 13 patients (93%) or 12 patients (86%), respectively. There were
subcutaneous stranding (n = 13) and skin involvement (n = 3).
Conclusion: Skeletal muscle lymphoma has distinguishing MR features that help
to differentiate muscle lymphoma from other soft tissue tumors and tumor-like
lesions.
B-005
11:06
Differentiating high-grade from low-grade chondrosarcoma with MR
imaging
H. Yoo 1, S. Hong1, J.-Y. Choi1, K. Moon1, N. Kim1, J. Lee2, J.-A. Choi2, H. Kang2;
1
Seoul/KR, 2Sungnam/KR (yoohj@radiol.snu.ac.kr)
Prupose: To evaluate the MR-imaging features to differentiate between high-grade
and low-grade chondrosarcoma and to determine predictors for this differentiation.
Methods and Materials: MR images of 42 pathologically proven chondrosarcomas
(28 LGCSs and 14 HGCSs) were retrospectively reviewed. There were 13-male
and 29-female patients with an age range of 23-72 years. On MR images, signal
intensity, contrast enhancement pattern, soft tissue mass formation and specific
morphologic characteristics including internal lobular architecture, outer lobular
margin and entrapped fat were analyzed. MR-imaging features to identify HGCS
and LGCS were compared by means of univariate analysis and multivariable
stepwise logistic regression analysis.
Scientific Sessions
B-006
11:15
Imaging patellar tumors: Retrospective study of 32 cases
R. Rinaldi, D. Vanel, R. Casadei, M. Alberghini, M. Mercuri, U. Albisinni;
Bologna/IT (ugo.albisinni@ior.it)
Purpose: From 1916 and among 23000 musculo-skeletal tumours, 41 involved
the patella. The aim of the study is to show the imaging patterns to help the
diagnosis.
Methods and Materials: Thirty-two had imaging studies (radiographs: 30, CT: 18,
MR: 9) and histology that were reviewed. There were 13 females, 19 males, from 11
to 68 years old. Benign tumors were seven giant cell tumors, five chondroblastomas,
six osteoid osteomas, two aneuvrismal bone cysts, one angioma, and one mucoid
cyst. Malignant tumors were four metastases, one lymphoma, one plasmocytoma,
and one angiosarcoma, There were also three hemangioendotheliomas.
Results: Chondroblastomas had thin and partially interrupted cortex in two cases;
in the other case, it was destroyed. Giant cell tumors were purely lytic and more
aggressive. The nidus of osteoid osteomas was always easily detected, even on
radiographs. Fluid levels were obvious on MR in the aneuvrismal bone cyst. The
primary tumor was known in three cases of metastases. Partial destruction of the
patella and huge soft tissue mass were seen in the lymphoma. The three hemangioendoteliomas had multiple poorly defined lesions of the knee.
Conclusion: Patellar tumors are rare, and usually benign. As the patella is an
apophysis, the most frequent lesions are giant cell tumor in the adult, chondroblastoma in the younger. Osteoid osteomas are easily diagnosed. Multiple local
lesions are seen in vascular tumors and secondary malignancies. Lesions are
easily analysed on radiographs. CT and MR define better the cortex, soft tissue
extension, and fluid levels.
B-007
11:24
Input of ultrasonography for the exploration of subungual glomus tumors
of fingers: Retrospective study of 21 tumors
J. Rousseau, H. Guerini, E. Pluot, D. Richarme, A. Feydy, A. Chevrot, J.-L. Drapé;
Paris/FR (julien.rousseau.jr@gmail.com)
Purpose: To retrospectively compare efficiencies of ultrasonography and MRI in
pre-operative assessment of subungual glomus tumors.
Methods and Materials: 21 subungual glomus histologically confirmed tumors
were analysed with ultrasonography and MRI. The results obtained by the two
techniques were compared. The parameters were the detection of the tumor (s),
the number, size, location of the tumor (s), margins analysis, power Doppler signal,
post-gadolinium enhancement, and presence of bone erosion.
Results: Nineteen percent (n=19/21) of the tumors were detected using ultrasonography, 100% were detected by MRI. The average tumor size was 3 mm with both
ultrasonography and MRI. Correlation between US and MRI estimates of tumor’s
location in axial (kappa = 0.909) and sagittal (kappa = 1) plane was excellent. None
of the observed tumors was hypovascularised with MRI, whereas 4 out of 19 (21%)
appeared hypovascularised with power Doppler ultrasonography. The two tumors
that were not detected using ultrasonography consisted in two tinny (1.7 mm both),
ill defined margins tumors without bone erosion.
Conclusion: Ultrasonography turns out to be reliable in the preoperative assessment of sub-ungual glomus tumors. It could be proposed as a first step method to
confirm the diagnosis and assess the extension of the tumor (s). MRI could then
be proposed in case of disagreement between the ultrasonography results and
the clinical diagnosis.
B-008
11:33
Diagnostic value of whole body magnetic resonance imaging and bone
scintigraphy in the detection of osseous metastases in patients with
breast cancer: A randomized, double-blinded and prospective study at two
hospital centres
S. Ohlmann1, M. Kirschbaum1, G. Fenzl2, D. Pickuth1; 1Saarbruecken/DE,
2
Püttlingen/DE (su.oh@web.de)
Purpose: To evaluate for the first time in a randomized, double-blinded and prospective approach the diagnostic accuracy of whole body MR imaging (WB-MRI)
and bone scintigraphy (BS) in the detection of bone metastases in a large and
homogeneous patient group with breast cancer.
Methods and Materials: 213 patients with breast cancer were examined for bone
metastases by WB-MRI and BS. Under standardized conditions the examinations
were performed separately at two different hospital sites. The images were reviewed
independently by two radiologists and two nuclear medicine specialists.
Results: In 141/213 patients (66%), WB-MRI and BS were concordantly negative;
in 4/213 patients (2%), both WB-MRI and BS demonstrated bone metastases.
There were discrepant findings in 14 cases. In 7 cases with normal WB-MRI, there
were false positive findings in BS. In 5 cases with normal bone scans, WB-MRI
revealed bone metastases. In 89% of patients with equivocal bone scans, WB-MRI
confidently excluded bone metastases. The sensitivity, specificity and positive and
negative predictive values of WB-MRI were 90, 94, 82 and 98%, respectively, and
those of BS were 40, 82, 36 and 91%, respectively.
Conclusion: WB-MRI has a much higher diagnostic accuracy in the detection
of osseous metastases than BS. These results have a major impact on both the
national and international guidelines on the diagnosis, therapy and follow-up of
breast cancer. WB-MRI should be given clear priority to BS in the diagnosis and
follow-up of bone metastases in these patients.
B-009
11:42
Value of whole-body MRI in correctly staging monoclonal plasma cell
disease: Comparison of the Durie/Salmon and the Durie/Salmon PLUS
staging system
K. Fechtner, J. Hillengass, L. Grenacher, S. Delorme, H.-U. Kauczor,
M.-A. Weber; Heidelberg/DE (kerstin.fechtner@med.uni-heidelberg.de)
Purpose: Whole-body MRI (wb-MRI) was used to investigate the concordance
of the Durie/Salmon (D/S) with the Durie/Salmon PLUS (D/S PLUS) staging
system regarding focal or diffuse infiltration in all stages of monoclonal plasma
cell disease.
Methods and Materials: A total of 403 untreated patients (22-86 years) with monoclonal gammopathy of undetermined significance (MGUS, n = 84), plasmacytoma (n
= 17), amyloidosis (n = 12) and multiple myeloma in all stages (MM, n = 325) were
examined with wb-MRI on a 1.5 T-system using T1 and fat-suppressed T2-weighted
sequences of the head, thorax, abdomen, legs, and spine yielding composed scans
between the skull vertex and the feet excluding the distal forearms. Two blinded
radiologists assessed in consensus the bone marrow infiltration pattern and focal
lesions, and also distinguished between intraosseous, corticalis-exceeding, and
soft tissue lesions with regard to D/S and D/S PLUS.
Results: Six MGUS patients (7%) and 10 plasmacytoma patients (59%) showed
focal lesions leading to an upgrading as MM stage IB (n = 12), IIA (n = 3) or IIIA
(n = 1) in D/S PLUS. In 290 MM patients (all stages) only 8 patients (3%) would
have been staged higher in D/S PLUS in comparison to D/S. In all amyloidosis
patients wb-MRI led to no change in classification. Among all 403 patients of our
population, 24 patients (6%) would have been staged higher in D/S PLUS when
compared with D/S using wb-MRI.
Conclusion: The classical D/S staging system is accurate in advanced disease,
whereas in case of limited disease (MGUS, plasmacytoma) wb-MRI reveals more
lesions and thus yields a more accurate classification.
B-010
11:51
Normal spinal bone marrow and degenerative endplate changes: Perfusion
MRI measurements related to age and sex
L.A. Moulopoulos1, T.G. Maris2, A. Gouliamos1, L. Vlahos1, V. Savvopoulou1;
1
Athens/GR, 2Iraklion/GR (vasosavopoulou@hotmail.com)
Purpose: To investigate differences in perfusion profiles of degenerative endplate
marrow changes and normal bone marrow of patients matched for age and sex
with perfusion MRI of the lumbosacral spine.
Methods and Materials: Ninety-two consecutive patients referred for evaluation
of low back pain or sciatica, without a history of malignant or chronic disease, underwent conventional MRI and perfusion MRI of the lumbosacral spine (group A).
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Results: On T1-weighted images, HGCSs (5 of 14) more frequently had high-signal
intensity than LGCSs (1 of 28; P 0.05). HGCSs (9 of 14) commonly exhibited only
peripheral enhancement, while most LGCSs (26 of 28) had peripheral and septal
enhancement (P 0.01). HGCSs (10 of 14) more commonly lose the characteristic
internal lobular structures within the tumor than LGCSs (4 of 28; P 0.01). Soft
tissue formation was more frequently observed in HGCSs (11 of 14) than in LGCS
(1 of 28; P 0.01). Entrapped fat within the tumor was seen in only 1 of 14 HGCSs,
whereas 26 of 28 LGCSs had entrapped fat (P 0.01). Results of multivariable
stepwise logistic regression analysis showed that soft tissue formation and entrapped fat within the tumor were the variables that could be used to independently
differentiate HGCS and LGCS.
Conclusion: There were several MR-imaging features of chondrosarcoma, which
could be helpful in distinguishing HGCS from LGCS. Among others, soft tissue
mass formation favored the diagnosis of HGCS, and entrapped fat within the tumor
was highly indicative of LGCS.
Scientific Sessions
Fifty-two patients from group A, who had degenerative endplate marrow changes
comprised group B. ROIs were placed on sites of normal marrow and degenerative changes on subtracted images. Time-intensity curves were generated for
both groups and perfusion parameters (wash-in (WIN), wash-out (WOUT), time
to maximum slope (TMSP), time to peak enhancement (TTPK)) were calculated.
Both groups were stratified into males and females younger or older than fifty years
and perfusion parameters for the two groups as well as for age- and sex-matched
subgroups of normal and degenerative marrow were compared by means of
student’s t-test. Sensitivity and specificity of perfusion parameters were evaluated
with ROC analysis.
Results: Perfusion parameters of degenerative changes differed significantly
from those of normal marrow even when the two populations were matched for
age and sex (p 0.05). Among all assessed perfusion parameters, a TTPK value
108 sec was most characteristic of degenerative changes (sensitivity 72.29%,
specificity 84.57%).
Conclusion: Perfusion MRI profiles of degenerative endplate marrow changes
of the lumbosacral spine clearly differ from those of normal marrow regardless of
patient’s age or sex and may reflect the underlying pathophysiologic changes.
the results with those of PET and CT alone by correlating imaging findings with
intraoperative staging.
Methods and Materials: A total of 22 consecutive patients with PC from gastrointestinal (N=13) and ovarian cancer (N=8) and mesothelioma (N=1) underwent
18 F-FDG-PET/CT before surgery and HIPEC. In a retrospective analysis of PET,
CT and fused PET/CT were separately and blindly reviewed for the extent of peritoneal involvement using the peritoneal cancer index (PCI). Imaging results were
correlated with the intraoperative PCI (13 regions) using Pearson’s correlation
coefficient and linear regression analysis.
Results: There was a strong and statistically significant correlation between the PCI
obtained with PET/CT and the surgical PCI in the overall assessment (region 0-12,
r=0.951, p 0.01) as well as in the regional analysis (region 0-8, r=0.703; region
9-12, r= 0.838) The correlation was lower for CT (region 0-12, r=0.919; region 0-8,
r=0.666; region 9-12, r= 0.754) and PET alone (region 0-12, r=0.793; region 0-8,
r=0.507; region 9-12, r=0.553).
Conclusion: In comparison to PET and CT alone, combined 18 F-FDG-PET/CT
yielded the best results in predicting PC and proved to be an useful tool for selecting candidates for peritonectomy and HIPEC.
10:30 - 12:00
B-013
Room C
GI Tract
SS 201a
Gastrointestinal cancer:
Detection and treatment response
Moderators:
S.A. Jackson; Plymouth/UK
M. Kantarcý; Erzurum/TR
B-011
10:30
Diffusion-weighted echo-planar MR images compared with late phase GdBOPTA-enhanced MR images in the detection of peritoneal implants
G. Patriarca, A. Filippone, R. Cianci, R. Basilico, A. Tartaro, M.L. Storto; Chieti/IT
(g.patriarca@rad.unich.it)
Purpose: To determine the usefulness of diffusion-weighted (DW) echoplanar
MR imaging compared with late phase Gd-BOPTA-enhanced MR images in the
detection of peritoneal implants.
Methods and Materials: Twenty-three patients with known peritoneal implants
underwent MR imaging at 1.5 T (Achieva, Philips). A single shot eco-planar diffusionweighted MR sequence was acquired using a unidirectional diffusion gradient with
two b values (b0 and b500 sec/mm2). Apparent diffusion coefficient (ADC) was
calculated for cerebrospinal fluid and for each peritoneal implant. A 3-D fat-saturated
T1-weighted late phase Gd-BOPTA-enhanced sequence was also obtained after
the completion of the dynamic study. Two radiologists evaluated MR images in two
separate reading sessions: A. late phase Gd-BOPTA-enhanced images, B. late
phase Gd-BOPTA-enhanced images combined with DW echoplanar images. Readers were asked to identify peritoneal implants, according to a four-point confidence
scale. ADC values were also calculated in implants 1 cm in size.
Results: A total of 92 lesions were identified during session A. Twenty-nine additional implants 1 cm in size were noted on the DW images. The mean ADCs
(pSD) values were 1.18 p 0.48 mm2 /sec for the solid and 2.82 p 0.20 mm2 /sec
for the cystic peritoneal implants. DW images significantly improved readers
confidence level.
Conclusion: Diffusion-weighted echo-planar MR imaging improves MR sensitivity
in the detection of peritoneal implants.
B-012
10:39
Value of 18 F-FDG-PET/CT to select patients with peritoneal
carcinomatosis for cytoreductive surgery and hyperthermic intraperitoneal
chemotherapy (HIPEC)
C. Pfannenberg, P. Aschoff, I. Königsrainer, M. Öksüz, J.T. Hartmann, S. Miller,
C.D. Claussen, A. Königsrainer; Tübingen/DE
(christina.pfannenberg@med.uni-tuebingen.de)
Purpose: Extensive cytoreductive surgery followed by hyperthermic intraperitoneal
chemotherapy (HIPEC) is associated with significantly longer survival in patients
with peritoneal carcinomatosis (PC). So far, no morphological imaging method has
proven to accurately assess the intraabdominal tumor spread for adequate selection of candidates for radical cytoreductive surgery. The aim of our study was to
predict the tumor load in patients with PC using 18 F-FDG-PET/CT and to compare
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10:48
Whole tumour quantitative measurement of first-pass perfusion of
oesophageal squamous cell carcinoma using 64-slice MDCT: Correlation
with microvessel density
T.-W. Chen, Z.-G. Yang, Y. Li; Chengdu Sichuan/CN (twchenscu@yahoo.com.cn)
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Purpose: To optimize a first-pass perfusion protocol with 64-slice MDCT for
determination of whole tumour microcirculation of esophageal squamous cell
carcinoma, and to assess correlations between perfusion parameters and microvessel density (MVD).
Methods and Materials: Thirty-one patients with surgically oesophageal squamous
cell carcinomas were enrolled into our study, and subdivided into subgroups according to status of lymph node metastasis. All patients underwent whole tumour
perfusion scan with 64-slice MDCT. Perfusion parameters, including perfusion (PF),
peak enhanced density (PED), blood volume (BV) and time to peak (TTP) were
measured. Postoperative tumour specimens were assessed for MVD. Differences
in perfusion parameters or MVD between subgroups were compared by Student
t-test. Pearson correlation coefficient tests were performed to determine correlations
between perfusion parameters and MVD.
Results: Mean values for PF, PED, BV and TTP of the whole tumour were
28.85p20.29 ml/min/ml, 23.16p8.09 Hu, 12.13p5.21 ml/100 g, and 35.05p13.85
sec, respectively. Mean MVD in whole tumour at magnification (×200) was
15.75p4.34 microvessel/tumour sample (vessels/0.723 mm2). Between patients
with and without lymph node metastasis, no statistical significances were found
in perfusion parameters (p 0.05), whereas there were statistical significances in
MVD (p 0.05). PED and BV were correlated with MVD (r=0.651 and r=0.977,
respectively, all p 0.05). However, PF and TTP were not correlated with MVD
(r=0.070 and r=0.100, respectively, all p 0.05).
Conclusion: First-pass perfusion technique at 64-slice MDCT could be valuable to
assess whole tumour microcirculation of oesophageal squamous cell carcinoma.
B-014
10:57
The spatial pattern of colorectal tumour and normal bowel perfusion
estimated using perfusion CT and two-dimensional fractal analysis:
Feasibility and repeatability
B. Sanghera1, V.J. Goh1, D. Wellsted2, I. Przybytniak2, S. Halligan3;
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Northwood/UK, 2Hatfield/UK, 3London/UK (b.sanghera@ic.ac.uk)
Purpose: To evaluate the feasibility and repeatability of fractal analysis for assessing the spatial pattern of colorectal tumour and normal bowel perfusion obtained
at CT.
Methods and Materials: Twenty patients with colorectal adenocarcinoma underwent a 65-second perfusion CT study from which a perfusion parametric map
was generated using validated commercial software (GE Healthcare). The tumour
was identified by a radiologist, segmented via thresholding, and fractal analysis
applied using in-house software: fractal dimension, abundance and lacunarity were
assessed for the entire outlined tumour, and for selected representative areas within
the tumour of low and high perfusions. Comparison was made with 10 patients
with normal colon (controls), processed in a similar manner, using two-way mixed
analysis of variance. Image analysis was repeated in 10 patients from each group
( 3 months between analyses) to assess measurement repeatability using BlandAltman statistics. Significance was at the 5% level.
Results: Fractal values were significantly higher in cancer than normal colon: mean
(SD) 1.71 (0.07) versus 1.61 (0.07) for fractal dimension (FD); 1.61 (0.07) and 7.82
Scientific Sessions
B-015
11:06
Gastrointestinal 18 F-FDG accumulation in PET/CT without corresponding
morphological mass: Early predictor of cancer development?
T. Heusner, U.-H. Kim, S. Hahn, M. Forsting, A. Stahl, G. Antoch; Essen/DE
(till.heusner@uni-due.de)
Purpose: Focal gastrointestinal FDG uptake can frequently be found on FDG-PET/
CT even in patients without known gastrointestinal malignancy. The aim of this
study was to evaluate whether increased gastrointestinal FDG uptake may identify
patients at risk for developing gastrointestinal malignancies.
Methods and Materials: A total of 681 patients without a history or CT-based evidence of esophagogastric or anorectal diseases underwent whole-body FDG-PET/
CT. The esophagogastric junction, the gastric wall, the wall of the rectal ampulla
and the anal canal were evaluated qualitatively and quantitatively for increased
FDG uptake. Patients with elevated FDG uptake on qualitative evaluation were
grouped into group A and patients without increased FDG uptake were assigned
to group B. Differences between the SUVmax were tested for significance by MannWhitney Wilcoxon’s test (P 0.05). Clinical and radiological follow-up (mean: 894
d p 473 d) served as the gold standard to determine whether patients developed
gastrointestinal malignancies.
Results: Gastroesophageal junction: mean SUVmax group A: 4.16, group B: 3.11;
P 0.001. None of the patients developed a gastroesophageal malignancy. Gastric
wall: mean SUVmax group A: 3.87, group B: 3.19; P = 0.004. One patient of group
B developed gastric cancer on follow-up. Rectal ampulla: mean SUVmax group A:
3.9, mean SUVmax group B: 3.0; P = 0.011. No patient developed rectal malignancies. Anal canal: mean SUVmax: 3.9, mean SUVmax group B: 2.7; P 0.001. No
patient developed anal malignancies.
Conclusion: Elevated esophagogastric or anorectal FDG uptake of patients without
known malignancies and without suspicious CT findings at these sites does not
predict malignancy.
B-016
11:15
Assessment of tumor microcirculation in rectum carcinoma with regard
to different pharmacokinetic models, intra-tumor heterogeneity and
therapeutic effects after neoadjuvant radio-chemotherapy
A.M. Hötker, P. Mildenberger, T. Junginger, C. Düber, T. Hansen, M. Menig,
A. Heintz, K. Oberholzer; Mainz/DE (hoetker@students.uni-mainz.de)
Purpose: Measurement of changes in DCE- MRI parameters of rectum carcinoma
patients before and after neoadjuvant radio-chemotherapy using two slices per
patient and measurement to compare the assessed results of different models
(Brix/Tofts) between each other and the different slices.
Methods and Materials: DCE- MRI measurements of 30 patients with rectum
carcinoma were performed on a 1.5 T MR system (TurboFLASH, FoV: 350 mm,
Matrix: 256x192, Slice: 7 mm, TR/TE/TI: 7.0/3.86/120 ms, Flip angle 12°, 200 Hz/px
Bandwith, Voxel size 1.37x1.37x7 m³) during intravenous contrast media application
before and after neoadjuvant radio-chemotherapy. For each measurement, two
slices were applied in maximal tumor extent. The resultant images were analyzed
semi-quantitatively and quantitatively (Brix and Tofts compartment models).
Results: Significant changes were found for several parameters including the
semi-quantitative time to peak (TTP, p 0.001) and the quantitative values kep from
the Brix model (p 0.001), K from the Tofts model (p 0.001) and AuCtP (area
under the curve till maximum enhancement, p 0.001). The percentage decrease
in exchange rate parameters of the applied pharmacokinetic models was similar
(both kep and K decreased about 50%). The two slices applied in maximal tumor
extent showed no significant different results.
Conclusion: Neoadjuvant radio-chemotherapy results in a significant change of
tumor microcirculation. Neither the slice selection in the maximal tumor extent affected the results in later analysis nor was it possible to find a relevant difference in
therapeutic effects between the corresponding parameters of the pharmacokinetic
models.
B-017
11:24
Value of diffusion weighted MR imaging for predicting tumour response to
chemoradiation therapy in patients with advanced rectal cancer
D.M.J. Lambregts1, C. Matos2, S. Gourtsoyianni3, A.G. Kessels1, G.L. Beets1,
M. Maas1, J.E. Wildberger1, R.G.H. Beets-Tan 1; 1Maastricht/NL, 2Brussels/BE,
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Iraklion/GR (d.lambregts@mumc.nl)
Purpose: Preoperative knowledge of good response to chemoradiation (CRT)
in locally-advanced rectal cancer (LARC) could allow selection for local excision
without compromising risk for local recurrence. Therefore selection between ypT0-2
and ypT3 is important. This study aims to evaluate the potential of diffusion weighted
MR-imaging (DWI) of rectal cancer for selecting these patients preoperatively.
Methods and Materials: 36 LARC-patients undergoing neoadjuvant CRT followed
by surgery were evaluated retrospectively. All patients underwent MR-imaging,
including T2W-FSE, prior and subsequent to CRT. Pre-CRT MRI included DWI.
Pre-CRT apparent diffusion coefficient (ADC)-measurements of all tumours were
performed. Tumour-volume reduction was assessed on pre- and post-CRT images.
Histology was the reference for T-stage. Mann-Whitney and ROC-curve analyses
were performed to assess value of pretreatment ADC-values for predicting reduction in tumour-volume and histological outcome.
Results: ADC-values were significantly lower in tumours with 75% downsizing
after CRT as compared to those with little downsizing (mean 651 vs 869 mm2/s,
p=0.002). ADC-values were also lower in tumours downstaged to ypT0-2 as
compared to those with no downstaging. (mean 669 vs 821 mm2/s, p=0.04). Area
under the ROC-curve for combined assessment of volume reduction and ADCvalues for prediction of downstaging to ypT0-2 was 0.800, compared to 0.699 for
ADC-measurements only.
Conclusion: 1. Diffusion weighted MRI could aid in selection of patients, and likely
to show good response to neoadjuvant treatment. 2. Low primary ADC-values
correspond with good response to CRT. 3. Combined assessment of primary
ADC and volume-reduction after CRT could be useful for prediction of tumourdownstaging to ypT0-2.
B-018
11:33
Role of DWI images in the evaluation of tumor regression grade after
chemoradiation treatment in patients with rectal cancer: Comparison with
18 FDG-PET-CT study
D. Ippolito1, L. Guerra1, F. Invernizzi2, S. Sironi1, F. Fazio3, C. Messa1; 1Monza/IT,
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Lecco/IT, 3Milan/IT (davide.atena@tiscalinet.it)
Purpose:To compare the diagnostic performance of MR diffusion imaging with 18FDG PET/CT in determining the response to chemoradiation therapy, in patients
with locally advanced rectal cancer (LARC).
Methods and Materials: A total of 23 patients with histologically proven diagnosis
of rectal carcinoma were enrolled in our study. All the patients underwent a whole
body 18-FDG PET/CT scan and a pelvic MR examination including DW-imaging
for staging (PET1, MR1) and after chemoradiation therapy (PET2, MR2). Then,
all the patients underwent total mesorectal excision and the histological results
were compared with imaging findings. MR scanning was performed on 1.5 T
magnet, including T2-weighted multiplanar imaging and in addition DW-images
with b-value of 0 and 1,000 mm²/sec. On PET/CT, SUVmax of rectal lesion was
calculated for PET1 and PET2 with the determination of percentage variation of
SUVmax ($SUV).
Results: Primary tumor was detected in all the patients at both MR imaging and
FDG-PET/CT. On DWI, the tumor appeared as high signal intensity as compared
with the normal rectal wall. Mean ADC values were on MR1: 0.86 p 0.22 x 10-3 mm²/
sec and on MR2: 1.43 p 0.25 x 10-3 mm²/sec. Mean SUV-max values calculated at
the same position were respectively 16.22 p 9.05 and 4.5 p 2.5. After neoadjuvant
therapy, all patients underwent surgery. In accordance with Mandard's criteria, 16
out of 23 patients were considered to be responders (TRG1 and TRG2), while the
remaining were considered to be non-responders. The mean values of SUVmax in
PET1 was higher than the mean value of SUV-max in PET2 (P 0.001), whereas
the mean ADC values were lower in RM1 than in RM2 (P 0.001), with a $SUV
and $ADC respectively of 67 and 69%, obtaining correlation between TRG, $SUV
and $ADC.
Conclusion: DWI is an effective diagnostic tool in the evaluation of rectal cancer
response after chemoradiotherapy and has an accuracy rate similar to that of
18 FDG PET/CT.
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(0.62) and 6.89 (0.47) for fractal abundance (FA; p= 0.001). Fractal values were
lower in 'high' than 'low' perfusion areas. Lacunarity curves were shifted to the right
for cancer compared with normal colon. Repeatability was good with a within subject
coefficient of variation of 0.005-0.08; and repeatability coefficient of 1.6-22%.
Conclusion: Colorectal cancer perfusion mapped by CT demonstrates fractal
properties, which is different to normal bowel. Fractal analysis is repeatable providing
an in vivo quantitative measure of the spatial pattern of perfusion.
Scientific Sessions
B-019
10:30 - 12:00
11:42
Added value of diffusion-weighted imaging for prediction of complete
response to neoadjuvant chemoradiotherapy for locally advanced rectal
cancer
S. Kim, J. Lee, S. Hong, G. Kim, J. Lee, J. Han, B. Choi; Seoul/KR
(radiresi@radiol.snu.ac.kr)
Purpose: To evaluate the added value of diffusion-weighted imaging (DWI) in
predicting the complete response (CR) to neoadjuvant chemoradiotherapy (CRT)
for locally advanced rectal cancer.
Methods and Materials: A total of 40 consecutive patients (28 men, 12 women;
mean age, 58 years; range, 39-75 years) with locally advanced rectal cancer,
who underwent neoadjuvant CRT and subsequent surgery, were enrolled in this
retrospective study. All patients underwent pre- and post-CRT 1.5-T rectal MRI
plus post-CRT DWI. For qualitative analysis, two blind radiologists independently
reviewed both the conventional MRI and the combined image set of MRI with DWI at
a 2-week interval and recorded their confidence level using a five-point scale for the
CR to neoadjuvant CRT. The diagnostic accuracy for each reviewer was calculated
using ROC analysis. For quantitative analysis, the third radiologist measured the
apparent diffusion coefficient (ADC) values of the region of interest three times.
The mean ADC values were compared between the CR group and the non-CR
group. Pathology reports served as the reference standard.
Results: The diagnostic accuracy (Az) for predicting the CR was significantly improved after the additional review of DWI for both reviewers (for reviewer 1, 0.676
versus 0.876, P = 0.005; for reviewer 2, 0.658 versus 0.815, P = 0.036, respectively).
The mean ADC (1.62 ×10-5 cm2/s) of the CR group (n = 11) was significantly higher
than that (1.04 ×10-5 cm2/s) of the non-CR group (n = 29; P 0.0001; t-test).
Conclusion: Adding DWI to conventional MRI provides better diagnostic accuracy
than conventional MRI alone for predicting the CR to neoadjuvant CRT for locally
advanced rectal cancer.
B-020
11:51
Locally advanced rectal cancer (LARC): Role of 18-FDG PET/CT in
evaluation of response to neoadjuvant radiochemotherapy
D. Ippolito1, L. Guerra1, F. Invernizzi2, S. Sironi1, C. Messa1, F. Fazio3; 1Monza/IT,
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Lecco/IT, 3Milan/IT (radiobicocca@unimib.it)
Purpose: To assess the value of 18-FDG PET/CT in evaluationof rectal cancer
response to neoadjuvant chemoradiation therapy.
Methods and Materials: A total of 23 patients with locally advanced primary rectal
cancer were enrolled in our study. All the patients underwent a diagnostic staging
with 18-FDG PET/CT before (PET 1) and 1 month after the chemoradiation treatment (PET 2). Images were correlated with pathological features by tumor regression
grading. For each examination, the mean value of SUVmax was calculated in PET
1 and PET 2. The percentage of SUVmax decrease, from baseline to presurgical
examination, was also evaluated ($SUV) and correlated with pathologic response
classified as tumor regression grade score (TRG). Pathologic TRG values were
obtained in accordance to Mandard classification (TRG 1 = complete regression;
TRG 5 = absence of regression).
Results: All the patients underwent total mesorectal excision after preoperative
treatment. Out of 23 patients, 16 were considered to be responders (9 with TRG 1; 7
with TRG 2), while the remaining 7 patients were considered to be non-responders
(5 with TRG 3; 2 with TRG 5). The mean value of SUVmax PET 1 was: 17.5 p 9.4,
being significantly higher (P 0.001) than the mean value in PET 2: 4.3 p 2.5. The
percentage of reduction of SUV ($SUV) after chemoradiation therapy was 67%. A
significant correlation (linear regression) was found between TRG and SUVmax in
PET2 (P 0.001) and also between TRG and $SUV (P 0.05).
Conclusion: The 18-FDG PET/CT has a role as prognostic tool in the evaluation
and prediction of neoadjuvant CRT response in patients with locally advanced
rectal cancer.
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Room E1
Contrast Media
SS 206
New perspectives in contrast-enhanced imaging
Moderators:
E. Di Cesare; L‘Aquila/IT
T. Persigehl; Münster/DE
B-021
10:30
Superparamagnetic iron oxide-enhanced diffusion-weighted magnetic
resonance imaging for assessment of small ( 1 cm) malignant focal
lesions in the liver
D. Kim, J. Yu; Seoul/KR
Purpose: To retrospectively compare the diffusion-weighted imaging (DWI) before
and after superparamagnetic iron oxide (SPIO) injection during the hepatic MRI for
assessment of sub-centimeter malignant lesions in the liver.
Methods and Materials: Eight patients with 19 hepatocellular carcinomas (HCCs)
and 12 patients with 35 hepatic metastases were enrolled at a single institution
between June 2007 and March 2008. All lesions were smaller than 1 cm. Hepatic
metastases were detected on SPIO-enhanced T2- and T2*-weighted images and
SPIO-enhanced T2- and T2*-weighted images were used as a reference standard
for the confirmation of hepatic metastases. All HCCs were confirmed by either surgery, iodized oil accumulations after chemoembolization or increased size during
the short-term follow-up. Pre- and post-SPIO-enhanced DWI (b values of 50, 400
and 800 s/mm2) was performed by 1.5 T MRI unit. Confidence score of each lesion
on pre-contrast DWI (pre-DWI) and ferucarbotran-enhanced DWI (SPIO-DWI) were
rated by two independent radiologists using five-grade scales. The Wilcoxon signed
rank test was used to differentiate the techniques.
Results: Compared to pre-DWIs (mean 3.76, 3.54, 3.28 for b = 50, 400, 800 s/mm2),
SPIO-DWIs (mean 4.19, 4.04, 3.78 for b = 50, 400, 800 s/mm2) revealed higher
confidence scores. SPIO-DWIs (b = 400 and 800 s/mm2) showed significantly higher
confidence scores than pre-DWIs (b = 400 and 800 s/m m2; P 0.05).
Conclusion: SPIO-enhanced DWI is an easily applicable method for detection of
sub-centimeter malignant lesions in patients with malignancy and liver cirrhosis
and is superior to DWI.
B-022
10:39
Normal dynamic contrast enhancement patterns of the upper abdominal
organs after administration of gadolinium-EOB-DTPA in comparison to
gadolinium-BT-DO3 A
J.P. Kühn, K. Hegenscheid, R. Puls, N. Hosten; Greifswald/DE
(kuehn@uni-greifswald.de)
Purpose: To investigate whether dynamic MRI of the upper abdominal organs,
with gadolinium-EOB-DTPA, a hepatobiliary contrast agent, has sufficient contrast
enhancement patterns such as extracellular contrast agents.
Methods and Materials: Dynamic gadolinium-EOB-DTPA enhanced MR-imaging
of pancreas, spleen, kidney, liver and abdominal aorta was performed in 50 patients.
A gadolinium-BT-DO3 A enhanced MRI control group of 50 patients was added. Dynamic imaging, using a T1-weighted VIBE gradient-echo sequence (3.35/1.35 [TR/
TE], 12° flip angle), was performed before, 20 sec (arterial), 55 sec (portal venous)
and 90 sec (hepatic venous) after a bolus injection of gadolinium-EOB-DTPA (0.25
mol/l) or gadolinium-BT-DO3 A (1.0 mol/l). Enhancement index was calculated for
each organ and time. Both groups were compared and analysed statistically.
Results: All MR-examinations of both groups were of diagnostic quality. During the
early dynamic phases significant lower mean enhancement indices were observed
in the gadolinium-EOB-DTPA group than in the gadolinium-BT-DO3 A group: pancreas (pv: 0.66, 1.39, pb0.001; ven: 0.51, 1.36, pb0.001), spleen (pv: 1.54, 2.41,
pb0.001; ven: 1.19, 2.23, pb0.001), renal cortex (pv: 1.76, 2.63, pb0.001; ven: 1.60,
2.63, pb0.001), and liver (pv: 0.76, 0.94, p=0.016; ven: 0.76, 1.04; pb0.001). In the
abdominal aorta the mean enhancement index was higher after bolus injection of
gadolinium-EOB-DTPA (art: 3.33, 2.23; pb0.005).
Conclusion: In early dynamic MR-images of the upper abdominal organs higher
gadolinic concentration of gadolinium-BT-DO3 A has a significant benefit compared
to the liver cell specific contrast agent gadolinium-EOB-DTPA. Higher protein binding
resulting in increasing relaxivity of gadolinium-EOB-DTPA compensates the low
gadolinium concentration in the abdominal aorta.
Scientific Sessions
B-023
10:48
Imaging delay for optimum detection of colorectal liver metastases using
Gd-EOB-DTPA (Primovist®)-enhanced MRI
N. Bharwani1, A.M. Riddell2, T. Wallace2, E. Scurr2, D.-M. Koh 2; 1London/UK,
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Sutton/UK
B-024
10:57
The late phase of contrast-enhanced ultrasonography (CEUS) and
magnetic resonance imaging (MRI) with hepatospecific contrast material
(Gd-BOPTA) in the characterization of solid focal liver lesions
A. Gallotti1, M. D’Onofrio2, V. Cantisani3, F. Calliada1, R. Pozzi Mucelli2; 1Pavia/IT,
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Verona/IT, 3Rome/IT (annagallotti@virgilio.it)
Purpose: To compare the late phase of CEUS with the hepatobiliary phase of
CE-MR with Gd-BOPTA in the characterization of solid focal liver lesions in terms
of benignity and malignancy.
Methods and Materials: A total of 147 solid focal liver lesions (38 focal nodular
hyperplasias, 1 area of focal steatosis, 3 regenerative nodules, 8 adenomas, 11
cholangiocarcinomas, 36 hepatocellular carcinomas and 49 metastases) were
retrospectively evaluated in a multicentric study, both with CEUS and CE-MR
performed with Gd-BOPTA (Multihance, Bracco, Milan, Italy). All the hypo-echoic/
intense lesions were considered malignant. Lesions thought to be malignant were
cito-hystologically proven. Lesions thought to be benign were followed-up. Sensitivity,
specificity, positive (PPV) and negative (NPV) predictive values and accuracy were
calculated for the late phase of CEUS and for the hepatobiliary phase of CE-MR,
respectively, and in association.
Results: There were 42 benign focal liver lesions and 105 malignant. The diagnostic errors were 13 of 147 (8.8%) by CEUS and 12 of 147 (8.2%) by CE-MR.
Sensitivity, specificity, PPV, NPV and accuracy of the late phase of CEUS were
90, 93, 97, 80 and 91%, while of the hepatobiliary phase of CE-MR were 91, 93,
97, 81 and 92%, respectively. If we considered both techniques, the misdiagnosis
diminished to 3 of 147 (2%) and sensitivity, specificity, PPV, NPV and accuracy
were 98, 98, 99, 95 and 98%.
Conclusion: The association between the late phase of CEUS and the hepatobiliary phase of CE-MR is more accurate than the two techniques separately in the
characterization of solid focal liver lesions in terms of benignity and malignancy.
B-025
11:06
Contrast-enhanced ultrasound after direct intraarterial contrast injection
for guiding endovascular liver-directed therapies
G. Bizzarri, V. Anelli, D. Valle, S. de Nuntis, A. Bianchini; Albano Laziale/IT
(bizzarrigiancarlo@libero.it)
Purpose: We propose contrast-enhanced ultrasound (CEUS) after direct intraarterial injection of US contrast as a guiding tool of TACE and precision TACE, because
it allows a precise visualization of the territories fed by the cannulated artery.
B-026
11:15
The use of contrast-enhanced ultrasound for the characterization of
neovascularization in carotid atherosclerotic plaques
D.-A. Clevert, T. Saam, W. Sommer, M.F. Reiser; Munich/DE
(Dirk.Clevert@med.uni-muenchen.de)
Purpose: To evaluate the use of contrast-enhanced ultrasound in the neovascularization of carotid atherosclerotic plaques.
Methods and Materials: A total of 33 patients with kown atherosclerotic plaques in
the carotid artery were examined with contrast-enhanced ultrasound to evaluate the
features of neovascularization within this plaque. Additionally, these plaques were
analyzed and correlated with plaque size and echogenicity. For contrast-enhanced
ultrasound, we injected 2.4 cc of SonoVue (Bracco, Italy) i.v. The examinations were
performed using the Sequoia 512 (Siemens / Acuson, Mountain View) with a 15
Mhz or 17 Mhz probe by using the CPS software.
Results: There were 41 atherosclerotic plaques, 27 of which (19 soft and 8 mixed)
enhanced after injection of SonoVue. The enhancement occurred from the carotid
wall to the center of the plaque with a short-line pattern in 15 plaques, whereas 12
plaques enhanced from both the carotid wall and the carotid lumen, with just a little
spot pattern. The arrival time of contrast was later in the plaques than in the carotid
artery and the time to peak was longer in the plaques than in the carotid lumen.
Among the 14 unenhanced plaques, 4 were hard, 3 were calcified, 2 were soft, and
5 were mixed. The unenhanced plaques had a thickness of 2.7 mm.
Conclusion: In our small patient population, contrast-enhanced ultrasound allows
the dynamic evaluation of neovascularization within carotid plaques and neovascularization may correlate with plaque morphology.
B-027
11:24
Contrast enhanced ultrasound (CEUS) in the assessment of antiangiogenic effects: Early prediction of the anticancer activity of
bevacizumab in a mouse xenografted model
R. Watanabe, T. Munemasa, M. Matsumura; Tokyo/JP
(watanabe.rira.vi@daiichisankyo.co.jp)
Purpose: To investigate the feasibility of CEUS for prediction of the anticancer activity of anti-angiogenic drugs, we analyzed the contrast enhancement of xenografted
tumors in mice treated with bevacizumab.
Methods and Materials: Thirty nude mice were subcutaneously implanted with
human osteosarcoma. After, 2 weeks, mice were allocated into 2 groups (n = 10)
and bevacizumab or saline treatment was initiated (i.p. ×4 at 3-day interval). CEUS
with a microbubble agent, Sonazoid, was performed before and 2, 6, 9 and 13 days
after initiation of the treatment. Intratumoral perfusion areas were quantified by
binarizing the grayscale images. Intratumoral microvessels were observed by CD31
immunohistochemistry at 14 days. The tumor size, intratumoral perfusion area and
its ratio were compared between the groups at each time point by t-test.
Results: Tumor growth was slower in the bevacizumab group, but the difference
did not reach statistical significance. Contrast enhancement in the tumors visually
decreased from 6 days in the bevacizumab group, while strong enhancement
remained in the control group. The perfusion area increased only in the control
group and was significant at 9 and 13 days (P = 0.0073 and P = 0.0108). The ratio
of the perfusion area decreased in the bevacizumab group, while it increased in
the control group and was significant at 9 and 13 days (P = 0.0005 and P = 0.001).
Intratumoral microvessels were obviously fewer in the bevacizumab group than in
the control group.
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Purpose: To determine the optimum imaging delay for the detection of colorectal hepatic metastases using Gd-EOB-DTPA (Primovist®) by measuring lesion
contrast-to-noise ratio (CNR), liver signal-to-noise ratio (SNR) and diagnostic
performance using T1-weighted imaging at dynamic imaging, 20 min, 1 hour and
4 hours post contrast.
Methods and Materials: A total of 20 patients with colorectal metastases underwent MR imaging before and after (breath-hold T1-weighted imaging dynamically at 20 min, 1 hour and 4 hours) Primovist® administration. Four image sets
(unenhanced T1 and T2-weighted images, together with one of four post-contrast
T1-weighted) were independently reviewed by two experienced radiologists in
consensus. The likelihood of malignancy was scored on a five-point scale and
results compared by ROC analysis. The gold standard was pathology and follow-up
imaging. For each post-contrast T1-weighted study, lesion CNR and liver SNR were
computed from ROI drawn around metastases, parenchyma and air. Results were
compared using t-test.
Results: A total of 87 metastases and 13 benign lesions were found. Imaging
at 1 hour post-contrast (S1hr) resulted in the highest diagnostic accuracy (Az =
0.82) compared with Sdyn (Az = 0.70), S20 min (Az = 0.78) or S4hrs (Az = 0.69).
However, the difference was not statistically significant (P 0.05, variance z-test).
CNR was higher at 1 hour (mean 250) compared to 20 min (mean 213; P = 0.004)
or 4 hours (mean 158; P = 0.001). There was no significant difference in SNR at
20 min or 1 hour (P = 0.31), but both were significantly higher than at 4 hours
(mean 414; P 0.01).
Conclusion: The highest lesion CNR and diagnostic accuracy for detecting colorectal metastasis were achieved using T1-weighted imaging at 1 hour post-contrast,
which may reflect lesion contrast washout.
Methods and Materials: A total of 30 consecutive patients, 20 with unresectable
HCCs and 10 with metastatic liver disease underwent TACE or precision TACE.
For each superselective angiography CEUS was performed after injecting 0.5 ml of
Sonovue (Bracco) in the microcatheter. For all patients, the aim was to thoroughly
embolize the segments harboring the pathologic tissue. The ability of CEUS to
predict the treated area was evaluated. The grade of vascularity at CEUS was
correlated to the treatment outcome in terms of lipiodol uptake or necrosis.
Results: In all cases, the enhancing area after CEUS strictly correlated with the
treated area at CT control after 24 hours, and at CEUS demonstrated a faintly
lipiodol uptake and no significant response after precision TACE. All hypervascular
lesions showed a good early response to treatment in terms of lipiodol uptake and
necrosis, while three cases with hypovascular HCCs and two cases with hypovascular metastases showed reduced or no response. In 9 cases, CEUS changed the
strategy of treatment and in 11 increased the operator confidence.
Conclusion: CEUS with intraarterial injection of US contrast media can be a valid
tool for increasing the precision of endovascular liver-directed therapies and can
increase the efficacy and safety profile by sparing normal liver parenchyma. The
major limit is the reduced visibility of deep-seated lesions.
Scientific Sessions
Conclusion: CEUS has potential for early prediction of the anticancer activity
of bevacizumab by visualizing intratumoral perfusion depressions that reflect its
anti-angiogenic effects.
B-028
11:33
Contrast-enhanced ultrasound in comparison to color duplex ultrasound
and multislice computed tomography (MS-CT) angiography in the
detection of endoleak following endovascular aneurysm repair
D.-A. Clevert, S. Weckbach; Munich/DE (Dirk.Clevert@med.uni-muenchen.de)
Purpose: The purpose of this study was to compare color duplex ultrasound (CDU),
contrast-enhanced ultrasound (CEUS) and multislice computed tomography (MSCT) angiography in the routine follow-up of patients following endovascular repair
(EVAR) of abdominal aortic aneurysm (AAA).
Methods and Materials: A total of 129 consecutive patients with AAA underwent
endovascular aneurysm repair and were imaged with CDU, CEUS and MS-CT
angiography at regular intervals after the procedure. Each imaging modality was
evaluated for the detection of endoleaks. The presence of endoleaks was analyzed
and the conspicuity of findings assessed.
Results: CTA was used as the gold standard in determining the presence of endoleaks. CDU was true positive for endoleaks in 17/129 patients (13.2%) and false
positive for endoleaks in 6/129 patients (4.6%). The sensitivity of CDU was therefore
32.3% and its specificity 92.8%; the positive and negative predictive values were
0.71 and 0.72, respectively. CEUS was true positive for the detection of endoleaks
in 45/129 patients (34.9%) and false positive in 6/129 patients (4.6%). The sensitivity of CEUS was therefore 100% and its specificity 93%; the positive and negative
predictive values were 0.88 and 1. In the follow-up, the six false-positive endoleaks
in CEUS were confirmed as true-positive endoleaks by CEUS and MS-CT.
Conclusion: In the patient group, CEUS seemed to be more accurate in demonstrating endoleaks after EVAR than MS-CT angiography and may be considered as
a primary surveillance modality, whereas CDU alone is not as sensitive as CEUS
and MS-CT angiography in the detection of endoleaks.
B-029
11:42
Image quality of multidetector CT coronary angiography using high iodine
concentration contrast material: Comparison of iopromide 370 versus
iomeprol 400
Y. Choe, D. Ye; Seoul/KR (yhchoe@skku.edu)
Purpose: To compare the image quality of coronary CT angiography (CCTA)
between the group with iopromide 370 and those with iomeprol 400.
Methods and Materials: In this prospective study, CCTA was performed in 130
enrolled patients using a 64-slice MDCT (Toshiba, Aquilion). Patients were randomized to 2 groups (65 patients for each group). 70 mL of iopromide 370 (Group
A; Ultravist 370) or 70 mL of iomeprol 400 (group B; Iomeron 400) was injected at
4 mL/sec for CCTA. The degree of CT attenuation was measured in 6 locations of
coronary arteries and 4 locations of aorta using ROI. Curved planar reconstruction
and volume-rendered images of 13 coronary artery segments were evaluated by
2 readers in consensus. For each segment, image quality was graded in a 4-point
scale with 1 for excellent enhancement.
Results: The attenuation values in coronary arteries and aorta were similar
between two groups without statistical significance. Mean attenuation values in
coronary arteries in groups A and B were 452.7 p 92.7 HU and 459.9 p 88.7 HU
(P = 0.71), respectively. Mean attenuation values in the aorta in groups A and B
were 437.4 p 82.5 HU and 444.6 p 84.0 HU (P = 0.33), respectively. Mean image
quality score of 13 coronary artery segments in groups A and B was 1.13 p 0.33
and 1.18 p 0.41, respectively. There was no significant difference in image quality
score of each coronary segment in two groups.
Conclusion: The image quality of CCTA using iopromide 370 or iomeprol 400 is
equally excellent.
B-030
11:51
Influence of body weight, body mass index and heart rate on coronary
attenuation in dual-source coronary CT-angiography
K. Anders, U. Baum, S. Achenbach, D. Ropers, A. Renz, W.A. Bautz; Erlangen/DE
(katharina.anders@uk-erlangen.de)
Purpose: An inverse correlation between body weight (BW) and vascular attenuation is known for abdominal vessels. Does early contrast in coronary CT-angiography
(corCTA) obey the same rules? In this study, attenuation in corCTA with a scantimebased injection protocol was correlated with BW, body bass index (BMI) and heart
rate (HR) as well as individual start delay (iSD) as indirect circulation marker.
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Methods and Materials: 200 consecutive corCTA datasets with a scantime-based
injection protocol (amount of contrast = scantime x 5 ml + 5 ml; transit time determined by testbolus) were used for retrospective analysis. ROI measurement was
performed in the proximal coronaries. The calculated mean of those 4 measurements was correlated with BW, BMI, HR and iSD.
Results: 183 datasets were available for correlation. Mean amount of contrast used
was 60 ml. Mean attenuation was 382 Hounsfield units (HU). For all 183 patients,
correlation coefficients were -0.59, -0.40, -0.19 and 0.03 for HU vs. BW, BMI, HR
and iSD, respectively. Subgroup analysis according to the amount of contrast (50,
55, 60, 65 and 70 ml) yielded the following correlation: -0.71, -0.65, -0.74, -0.14
and -0.37 for BW, -0.51, -0.57, -0.54, 0.37 and -0.14 for BMI, -0.23, -0.39, -0.12,
-0.07 and 0.08 for HR, 0.23, -0.06, -0.07, -0.64 and 0.16 for iSD.
Conclusion: Even though corCTA is performed during cardiac “first-pass”, correlation between BW/BMI vs. coronary attenuation still exists. It is comparable to
recently published data for the pulmonary arteries (r=-0.26 to -0.48). Correlation
with indirect circulation markers remains inconclusive.
10:30 - 12:00
Room F1
Genitourinary
SS 207
Uterus and ovaries: MDCT and MR studies
Moderators:
M. Bekiesinska-Figatowska; Warsaw/PL
G. Ivanac; Zagreb/HR
B-031
10:30
Role of a 3D T2-weighted turbo-spin-echo sequence (VISTA) for
assessment of pelvic deep endometriosis: Initial clinical experience at 3 T
C. Roy, A. Matau, G. Bierry, A. Youssef, A. Wattiez; Strasbourg/FR
(Catherine.Roy@chru-strasbourg.fr)
Purpose: To prospectively assess the value of a 3D T2wTSE (VISTA) sequence
by comparison with a standard set of 2D T2wTSE to evaluate pelvic deep endometriosis.
Methods and Materials: A total of 34 women having severe endometriosis underwent MR at 3.0 T (Achieva, Philips) before surgery of the nodule with a standard
set of three orientations T2wTSE (TR/TE : 4,262 ms/80 ms, 0.6 x 0.7 x 3.5 mm3),
3:12 min and with a 3D T2w VISTA (TR/TE/FA : 2,113/200/120, 0.9 x 0.9 x 1.1 mm3,
4 : 58 min) with pelvic coil. SNR from fat, urine, nodule and nodule-fat CNR were
measured from ROI. Two independent radiologists correlated 3D TSE VISTA with
2D TSE and rated the image quality with the contrast impression of nodule/surrounding tissue, signal homogeneity and artefacts.
Results: Nodule SNR was lower with VISTA (258 p 11) than with 2D TSE (589p 15).
Urine, fat SNR and nodule-fat CNR were higher with 3D VISTA (1,527, 1,237,
985 p 11) than with 2D TSE (1,443, 1,197, 589 p 15), respectively. Image quality, CNR and signal homogeneity of transverse, coronal and oblique orientations
were rated significantly higher for 3D VISTA than for 2D TSE; but lower for sagittal (P 0.05). Minor flow artefacts did not alter diagnosis. Use of interactive 3D
MPR software for VISTA 3D data sets providing multiplanar views improvement
was considered as essential for the diagnostic confidence of pelvic structures
involvement.
Conclusion: At 3 T, unique 3D VISTA sequence with multiplanar high quality images and contrast provides accurate evaluation of severe deep endometriosis. It
makes multiple 2D acquisitions unnecessary.
B-032
10:39
Role of MDCT in identification of the bleeding site causing postpartum
bleeding or bleeding after dilatation and curettage: A comparison with
angiography
N. Lee, J. Yeom, S. Kim, C. Kim, J. Lee, U. Jeon, D. Suh; Busan/KR
Purpose: To retrospectively evaluate accuracy of MDCT for identification of the bleeding site causing postpartum bleeding or bleeding after dilatation and curettage.
Methods and Materials: Ethics committee approval and informed consent were
obtained. Thirty consecutive patients (mean age, 31.1 years; range, 24-39 years)
with postpartum bleeding or bleeding after dilatation and curettage underwent
MDCT prior to embolization. Two radiologists compared CT findings with those of
conventional angiography in consensus. Conventional angiography was used as
the standard of reference. Active bleeding on CT was defined as extravasation of
contrast material at contrast-enhanced CT. Presence of contrast extravasation in
Scientific Sessions
B-033
10:48
Modification of signal intensities of tumor and normal myometrium after
USPIO administration in patients with uterine malignancies: A quantitative
retrospective study on a large patient population
P. Paolantonio, R. Ferrari, M. Rengo, F. Vecchietti, P. Lucchesi, D. Caruso,
A. Laghi; Latina/IT (paolantoniopasquale@hotmail.com)
Purpose: To quantitatively evaluate the signal intensity modification of the myometrtium and uterine tumor after USPIO administration.
Methods and Materials: We retrospectively evaluated a patient population of 88
females, affected by uterine neoplasm, who were previously enrolled in a multicentric study on lynpho-specific properties of USPIO. For each patient, GRE T2*W
sequences acquired before and 24 hours after iv administration of 2.6 mg/kg body
weight of Sinerem (Guerbet, Paris, France) were available. Image analysis was
performed by two radiologists in consensus and included quantitative analysis of
signal intensity (SI) of both normal myometrium and neoplastic lesions before and
after USPIO administration. S/N and C/N were calculated. Quantitative data were
compared using Wilcoxon test (P 0.05).
Results: Quantitative analysis showed a statistically significant difference between
SI of the myometrium on plain-MRI and USPIO-enhanced-MRI with a mean SNR
difference of 16.1. Also, the tumor showed a significant reduction of SNR after
USPIO administration that was less strong compared to the myometrium SNR drop
(mean difference of 9.8). Therefore, C/N between the tumor and normal myometrium
significantly increased following USPIO administration.
Conclusion: Intravenous injection of USPIO provides a decrease of SI of both
the normal myometrium and tumor; negative enhancement of the myometrium
was much more evident for the myometrium compared to the tumor, leading to
higher tumor conspicuity. Further studies are necessary to assess the mechanism
of those effects.
B-034
10:57
Epithelial and stromal metabolite changes in the transition from cervical
intraepithelial neoplasia to cervical cancer: An in vivo 1H magnetic
resonance spectroscopic imaging study with ex vivo correlation
S.S. De Silva1, G.S. Payne1, V.A. Morgan1, T.E.J. Ind2, J.H. Shepherd2,
D.P.J. Barton2, N.M. deSouza1; 1Sutton Surrey/UK, 2London/UK
(Nandita.Desouza@icr.ac.uk)
Purpose: To establish the epithelial and stromal metabolite changes in pre-invasive
and invasive cervical cancer in vivo and correlate findings with magic angle spinning
(MAS) MR spectroscopy of tissue samples.
Methods and Materials: Forty-seven women (19 with cervical intraepithelial neoplasia [CIN], and 28 with cervical cancer) underwent endovaginal MR imaging at 1.5
T with T2-W scans in 3 orthogonal planes to the cervix and localized 2-D MR spectroscopy (PRESS technique, TR 1500 ms, TE 135 ms). Peaks from tCho, 2 ppm and
triglyceride-CH2 were measured in epithelial ( 50% epithelium, no tumour), stromal
( 50% stroma, no tumour) and tumour ( 30% tumour) voxels. The unsuppressed
water signal from the corresponding voxel was used as an internal standard.
Results: Analysable data was obtained from 17 CIN and 25 cancer patients. A
significant increase in tCho (p=0.03) and 2 ppm (p=0.007) was observed in tumour
voxels compared to epithelial voxels from pre-invasive patients but not compared
to epithelial voxels from patients with invasive cancer. There was a tendency to
higher tCho, 2 and 1.3 ppm triglycerides in stroma from cancer compared to CIN
patients, but these differences were not significant. Differences in 1.3 ppm -CH2
triglycerides were not significant between groups. There was no correlation between
tCho and -CH2 triglycerides in vivo and ex vivo.
Conclusion: Estimated concentrations of tCho and 2 ppm resonances increase in
both tumour and adjacent epithelium in progression from pre-invasive to invasive
cervical cancer.
B-035
11:06
Contrast-enhanced dynamic magnetic resonance imaging as a predictor of
radiosensitivity in cervical cancer
K.L. Szluha1, K. Lazanyi1, Z. Adamecz1, R. Poka1, J. Toth1, C. Andras1,
A. Horvath1, A. Abramyuk2, N. Abolmaali2; 1Debrecen/HU, 2Dresden/DE
(Kornelia.Lazanyi@oncoray.de, Szluha@dote.hu)
Purpose: The aim of this study was to measure radiotherapy-induced changes
in cervical cancer by means of contrast-enhanced dynamic magnetic resonance
imaging (DCE-MRI).
Methods and Materials: Ten patients with T2a cervical cancer were examined
with DCE-MRI before and after 3 x 6 Gy intracavitary high-dose rate radiotherapy
(HDRRT). DCE-MRI utilized dynamic T1-weighted imaging during intravenous
Gd-DTPA administration. After HDRRT, all patients underwent Wertheim-Meigs
operation. The DCE-MRI were analyzed by signal intensity ratio (SIR) and, a new
indicator, ratio of signal intensity changes in time (RISI) applied to cervical cancer
tissue and healthy uterus, muscle and fat as reference. Results of SIR and RISI
were compared with both pathological findings after Wertheim-Meigs operation
and clinical response.
Results: SIR and RISI averages of cervical cancer (89.06% and 15.36/sec) and
of healthy uterine tissues showed significant differences before and after HDRRT,
especially during the first pass (30 seconds). Both intratumoral enhancement differences and individual changes after radiotherapy were characteristic. SIR and
RISI levels were higher than 90% and 9.5/sec, respectively, and decreased more in
well-responding patients. A tumor activity decrease was predicted by DCE-MRI only
in cervical cancers where SIR and RISI decreases exceeded 40% after HDRRT.
With the latter patients, better disease-free survival (DFS) and local control (LC)
rates were observed.
Conclusion: In a preoperative evaluation comparative study, intra and interpatient variability of contrast enhancement in DCE-MRI was assessed. DCE-MRI
provides important information about individual tumor activity in cervical cancer
and its changes after radiotherapy, which may be helpful for follow-up and tumor
response prediction.
B-036
11:15
Evaluation of necrosis with DCE-MRI subtracted imaging as a predictor of
cervical cancer response to chemo-radiotherapy
L. Mannelli, E. Sala, A. Priest, L. Zhi-Yong, M. Zahra, D.J. Lomas; Cambridge/UK
(mannellilorenzo@yahoo.it)
Purpose: To retrospectively evaluate dynamic contrast enhanced magnetic resonance (DCE-MRI) subtracted imaging as predictor of chemoradiotherapy response
in patients with advanced cervical cancer.
Methods and Materials: 13 patients with advanced cervical cancer treated with
chemo-radiotherapy underwent DCE-MRI at 3 time-points: before treatment, after
2 weeks of chemoradiotherapy and at the completion of chemoradiotherapy (5
weeks) but before the start of brachytherapy. The MRI protocol included T1W axial
and T2W sagittal, axial and axial oblique images followed by a T1W perfusion
sequence (PWI). This consisted of a 3D T1W fast spoiled gradient echo (TR/TE
= 4.8/1.5 ms, flip angle = 18o) of 4 contiguous sagittal sections repeated every 3
seconds for a total of 180 seconds after contrast administration. Subtraction imaging was performed at 18, 78 and 138 seconds after contrast medium injection
using GE-AW 4.2_03 Image Combination (Version 3.0.63) subtraction tool based
on a voxel-by-voxel method. The percentage of tumour necrosis was assessed
on subtracted images using a visual analogous scale and was correlated with
radiological tumour response.
Results: 13 patients had a total of 38 MRI examinations. The pre-treatment percentage tumour necrosis assessed using arterial subtraction imaging (at 18 seconds)
showed an excellent inverse correlation with percentage of tumour regression (r
= -0.934, p 0.001). There was an excellent agreement between the two readers
(Cronbach's Alpha = 0.961).
Conclusion: This study shows that pre-treatment tumour necrosis assessed with
arterial image subtraction predicts the radiation response in cervix cancer. This
measurement may allow a tailored therapy for patients with cervix cancer.
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each anatomic location was recorded (left and right uterus, left and right cervix,
left and right vagina, left and right paravaginal or parauterine region, and left and
right rectus muscle). Sensitivity, specificity, positive and negative predictive values,
and accuracy of MDCT for detection of bleeding were assessed. We also assessed
the presence of additional abnormalities on CT that could influence the decision
of further treatment or diagnostic evaluation.
Results: MDCT depicted contrast extravasation in 27 of 30 patients. Overall
location-based sensitivity, specificity, accuracy, and positive and negative predictive
values of MDCT for detection of bleeding were 92% (46 of 50), 96% (240 of 250),
95% (286 of 300), 82% (46 of 56), and 98% (240 of 244), respectively. MDCT also
found additional abnormalities in 10 of 30 patients.
Conclusion: CT may be useful in the demonstration of the anatomic location
of a significant arterial hemorrhage as sites of intravenous contrast material
extravasation.
Scientific Sessions
B-037
11:24
Can quantitative dynamic contrast enhanced MR imaging (DCE-MRI) be
used to accurately characterize complex adnexal masses?
P. Dilks, P. Narayanan, A. Sahdev, R.H. Reznek, A. Rockall; London/UK
(philipdilks@hotmail.com)
Purpose: To evaluate and compare the accuracy of quantitative DCE-MRI with qualitative visual assessment in the characterization of complex adnexal masses.
Methods and Materials: MR imaging of 26 patients (age 17-80 years, mean 43
years) with a complex adnexal mass, presenting over a 24-month period, was
retrospectively reviewed and correlated with histology following resection. These
were categorised into benign (N = 14) and malignant (N = 12) groups. A total of
55 cases without either a solid tumour component, histology or dynamic imaging
were excluded. A 1.5 T unit was used to obtain T1, T2, fat suppressed T1 weighted
images and a 5-point dynamic series between 0 and 150 ms post-gadolinium administration (rate of 3 ml/s). Regions of interest (ROI’s) were drawn around the solid
tumour component and control ROI’s were drawn over muscle and myometrium.
Maximum early enhancement (MEE) and maximum relative enhancement (MRE)
parameters were compared between the groups in addition to a blinded visual
assessment of enhancement.
Results: There was no significant difference in tumour size or control ROI enhancement between the groups. The MEE (p 0.001) and MRE (p 0.05) were
significantly different between benign and malignant lesions. ROC analysis with a
cut off point of 250 for MEE gave a sensitivity of 100%, specificity of 92.8%, PPV
of 92.3%, NPV of 100% and accuracy of 96.2% for mass characterisation. Visual
scoring gave a sensitivity of 75%, specificity of 85.7% and accuracy of 80.7%.
Conclusion: Quantitative DCE-MRI can confidently predict malignancy in complex solid/cystic adnexal masses with greater accuracy than qualitative visual
assessment.
B-038
11:33
Imaging modalities for preoperative staging ovarian cancer: Comparison
between multidetector CT (MDCT) and MRI using diffusion-weighted
sequences with background body signal suppression (DWMRI)
Y. Badachi, J.-P. Akakpo, D. Grenier, E. Vincent, J.-P. Lefranc, P.A. Grenier,
O. Lucidarme; Paris/FR (yasmina.badachi@psl.aphp.fr)
Purpose: DWMRI is emerging as a new promising technique in imaging peritoneal
metastases. Our objective was to compare DWMRI to MDCT and surgical laparotomy in the preoperative assessment of ovarian cancers.
Methods and Materials: To date, preoperative MDCT and DWMRI (T1w, T2w and
DWIBS sequences) covering abdomen and pelvis of 15 patients were separately
reviewed by 2 independent observers asked to stage (Figo) the cancer and to
predict non-optimal resection. Criteria of non-resectability were retroperitoneal
presacral disease, lymph node enlargement above renal hilum, abdominal wall
invasion, liver metastases, implants of 2 cm on diaphragm, lesser sac, porta
hepatis, intersegmental fissure, gall bladder fossa; gastrosplenic, gastrohepatic
ligament and small bowel mesentery. Stage and resectability obtained with MDCT,
DWMRI were compared to the result of surgical laparotomy.
Results: For both observers, correct staging of the disease was achieved in 12
out of 15 patients with MDCT (1 overestimation, 2 underestimations) and with
DWMRI (2 overestimations, 1 underestimation). For both observers resectability
was correctly predicted by MDCT and DWMRI in 7 out of 7 (100%) patients. For
observer 1 non-optimal resectable disease was correctly predicted by MDCT and
DWMRI in, respectively, 6 out of 8 and 7 out of 8 patients and for observer 2 in,
respectively, 5 out of 8 and 6 out of 8 patients. By averaging the observers, sensitivity for suboptimal debulking were 68.7% for CT and 81.2% for DWMRI without
significant difference. The DWI sequence clearly helped the observers to depict
diaphragm and porta hepatis involvement.
Conclusion: DWMRI has at least a comparable sensitivity than MDCT to preoperatively stage ovarian cancer and to predict suboptimal debulking.
B-039
11:42
Combined high-resolution pelvic and whole-body sliding multislice MRI for
ovarian cancer staging: Comparison with MSCT
G. Pache, T. Baumann, A.-O. Schaefer, M. Langer; Freiburg/DE
(gregor.pache@uniklinik-freiburg.de)
Purpose: Comparison of combined high-resolution pelvic MRI and whole-body
sliding multislice (SMS), a novel MRI technique for axial moving table acquisitions,
with MSCT for staging of ovarian cancer patients.
Methods and Materials: A total of 20 patients with ovarian cancer underwent CT
and MRI examinations within a median interval of 3 days. The MR imaging protocol
(1.5 T) consisted of triplanar T2-weighted high resolution images of the pelvis and
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a whole-body axial TIRM and contrast enhanced FLASH-2D sequence in SMS
technique. Laparotomy and histopathology were used as the standard of reference.
CT and MRI images were independently randomized. Two radiologists evaluated all
detectable intra- and extrapelvic disease manifestations in both modalities.
Results: Concerning peritoneal spread MRI was superior in detecting diaphragmal
and liver surface lesions with 89% (8/9) and 92% (12/13) compared to 67% (6/9)
and 69% (9/13) for MSCT. MRI showed one false positive diaphragmal lesion. MRI
detected all cases of rectosigmoid infiltration (8/8), whereas MSCT had two false
negative findings. MRI could correctly rule out bladder and rectosigmoid infiltration
that had been suspected by MSCT in two cases. No cases of hepatic spread or
direct hepatic infiltration as well as enlarged abdominal or supradiaphragmal lymph
nodes were missed by either method.
Conclusion: Combination of high-resolution pelvic MRI and whole-body SMS
MRI was superior to CT for staging of local tumor extent and showed excellent
detection of peritoneal or metastatic spread from ovarian cancer. Consequently,
this imaging strategy raises the possibility of a one-stop staging regimen for ovarian
cancer patients with MRI.
B-040
11:51
Diffusion-weighted MR (DWI-MR) imaging in the assessment of tumour
grade in endometrial cancer
N. Bharwani, P. Narayanan, A. Sahdev, R.H. Reznek, A.G. Rockall; London/UK
Purpose: To determine if there is a correlation between tumour grade and apparent
diffusion coefficient (ADC) in endometrial cancer.
Methods and Materials: A total of 15 patients with endometrial cancer underwent
DWI-MR imaging (Philips Achieva 1.5 T system, torso phased array coil) using
six b-values (50, 100, 150, 250, 500, 750). ADC maps were produced and the
tumour ADC values were correlated with histological tumour grade obtained at
hysterectomy (14 patients) or endometrial biopsy (1 patient). MRI images were
independently reviewed by two experienced readers and intra- and inter-observer
variability documented.
Results: The mean ADC value (10-3 mm2/s) of grade 1 (n = 6), 2 (n = 2) and 3 (n =
3) tumours was 0.85 (SD 0.06), 0.94 (SD 0.002) and 0.79 (SD 0.08), respectively.
Using linear regression analysis, a good correlation (R = 0.60) was obtained between tumour grade and ADC value. There was a significant difference (P 0.05)
between ADC values of grade 1 and grade 3 tumours. No significant difference
was seen between ADC measurements for grade 1 versus 2 and grade 2 versus
3 tumours. One patient had benign endometrial hyperplasia and the endometrial
ADC value was 1.45.
Conclusion: High tumour grade is an adverse prognostic factor in endometrial
cancer. This study is ongoing, but preliminary data suggest a good correlation
between ADC values and histological grade. Potentially this information, taken in
conjunction with a biopsy, may improve pre-operative prognostication and thereby
optimise patient management.
10:30 - 12:00
Room F2
Breast
SS 202
New developments on digital systems
in breast diagnosis
Moderators:
P. Alonso-Bartolomé; Santander/ES
H. Bosmans; Leuven/BE
B-041
10:30
Breast tomosynthesis: Assessment of breast cancer size compared with
digital mammography and ultrasonography
D.B.R. Förnvik, S. Zackrisson, P. Timberg, T. Svahn, S. Mattsson, A. Tingberg,
I. Andersson; Malmö/SE (daniel.fornvik@med.lu.se)
Purpose: Mammographic tumor size measurement is difficult because breast
structures are superimposed onto a two-dimensional (2D) plane, potentially obscuring the tumor outline. Breast tomosynthesis (BT) is a 3D X-ray imaging technique
in which low-dose images are acquired under rotation of the X-ray tube through
a limited angle at a total dose comparable to digital mammography (DM). These
low-dose images are used to mathematically reconstruct a 3D image volume of the
breast, thus reducing the problem of superimposed tissue. The aim of this project
was to investigate whether breast cancer size can be more accurately assessed
with BT compared with DM and ultrasonography (US).
Scientific Sessions
B-042
10:39
Clinical performance of digital breast tomosynthesis compared to digital
mammography: Blinded multireader study
G. Gennaro1, A. Toledano2, E. Baldan1, C. di Maggio1, M. La Grassa1, I. Polico1,
A. Proietti1, A. Toffoli1, L. Pescarini1; 1Padua/IT, 2Toronto, ON/CA
(gisella.gennaro@pd.infn.it)
Purpose: To evaluate potential differences in clinical performance between digital
breast tomosynthesis (DBT) and digital mammography (FFDM).
Methods and Materials: 200 consenting women with breast lesions classified as
doubtful or suspicious at mammography and/or ultrasound were enrolled in the
study. They underwent digital mammography (CC, MLO) and tomosynthesis (MLO
only) on both breasts. The DBT prototype was an investigational equipment based
on a standard FFDM unit (Senographe DS, GE Healthcare), modified to acquire
multiple projections over a limited arc. DBT dose levels were kept equivalent to those
delivered for standard mammography examinations. Six experienced radiologists
reviewed independently left and right breasts of each patient with no access to
any clinical information. FFDM and DBT images of each breast were reviewed in
separate reading sessions; findings were identified, localized and rated according to
the ACR BIRADS scale. Clinical assessments from each radiologist were compared
with the truth and multiple-reader-multiple-case (MRMC) ROC analysis was applied
to a dataset of 371 breasts. This analysis summarizes areas under ROC curves
(AUCs) across radiologists for FFDM and DBT, and compares the results.
Results: AUCs for detecting breasts with malignant lesions were 0.884 (DBT)
versus 0.852 (FFDM). The 95% confidence interval (CI) for the difference lies
entirely above a delta=0.05 non-inferiority margin (-0.03 to 0.09; p=0.285). Similar
results were obtained when breasts with benign lesions were also considered
positive: 0.857 (DBT) versus 0.845 (FFDM), 95% CI for difference -0.03 to 0.05
(p=0.562).
Conclusion: In the study population, tomosynthesis (MLO) showed non-inferiority
versus two-view digital mammography.
B-043
10:48
Breast tomosynthesis reduces radiologist performance variability
compared to digital mammography
A. Smith1, E. Rafferty2, L. Niklason1; 1Bedford, MA/US, 2Boston, MA/US
(asmith@hologic.com)
Purpose: To study radiologist variability when using breast tomosynthesis in
conjunction with digital mammography.
Methods and Materials: 1000 patients were imaged using digital mammography
(2D) and breast tomosynthesis (3D). Cases included normals, recalls, benign
biopsies, and cancers. 310 cases were selected for two reader studies, totaling 27
radiologists. The breast radiologists lacked clinical experience with tomosynthesis
and were trained in a 2-day session. They then read the cases, first 2D, and then
evaluated the 2D+3D images. Evaluations used BIRADS and probability of malignancy metrics. Performance was measured using receiver operating characteristics
(ROC) curves, and recall rates for screening cases. Their performance variability
in area under the ROC curve (AUROC) and recall rates was studied separately for
2D and 2D+3D. This analysis was performed for all images, and subsets involving
masses and calcifications.
Results: For all cases, the variability, or standard deviation, of AUROC for the radiologists was 70% using 2D+3D compared to 2D alone. For pathologies containing
masses, the standard deviation of the AUROC for 2D+3D was even smaller - 50%
of the variation using 2D. The variability of AUROC for calcifications was equivalent
for 2D+3D compared to 2D. With recall rates for screening cases, the variability in
recall rates using 2D+3D was 50% of the variability using 2D.
Conclusion: Tomosynthesis has previously shown to improve radiologist performance. This study shows that the variability of performance is also reduced when
using tomosynthesis. This can be interpreted to mean that the use of tomosynthesis
gives radiologists improved confidence in their evaluations.
B-044
10:57
Clinical relevance of the standardised update value (SUV) in staging breast
cancer with FDG-PET/CT
A. Zytoon1, M. El-Kholy1, K. Murakami2, O. Ebied1; 1Menoufiya/EG, 2Tochigi/EG
(ashradio@gmail.com)
Purpose: FDG-PET/CT with standardized uptake value (SUV) estimation was
applied to breast cancer patients for the purpose of preoperative evaluation of the
extent of the disease.
Methods and Materials: FDG-PET/CT was performed preoperatively in 71 patients with breast cancer, and the maximum standardized uptake value (SUVmax)
of tumors, as well as combination of SUVmax and tumor marker CA 15-3 were
investigated for a significant association with lymph node spread and distant
metastasis.
Results: Tumor SUVmax high ( 3.1) was found to have a reliable predictive value
for lymph node spread (sensitivity 82.9%, specificity 75%, P 3.8)/CA. 15-3-Elevated
was found to be superior for the prediction of metastasis (sensitivity; 75%, specificity; 92.7%, P = 0.0001). Moreover, linear regression analysis identified the best
correlation was between SUVmax-High ( 3.1) with lymph node spread {correlation
coefficient (r2) = 0.580, P = 0.0001}, and SUVmax-High ( 3.8)/CA 15-3-Elevated
with distant metastasis {correlation coefficient (r2) = 0.677, P 0.0001}.
Conclusion: SUVmax is a reliable predictor of lymph node spread, and if combined
with tumor marker assay (CA 15-3) labeled SUVmax-High/CA 15-3-Elevated is sufficient for the early detection of breast cancer metastasis. This outcome suggests
that the FDG-PET/CT findings with SUV calculation could have a strong positive
impact on breast cancer patients.
B-045
11:06
Digital breast tomosynthesis (DBT) versus full field digital mammography
(FFDM): Comparison of a system performance using a contrast detail
phantom
A. Nitrosi, G. Borasi, M. Bertolini, F. Nicoli, A. Botti; Reggio Emilia/IT
(nitrosi.andrea@asmn.re.it)
Purpose: To evaluate the difference in performances of a 2D planar digital mammographic system versus tomosynthesis.
Methods and Materials: A contrast detail phantom was obtained embedding a
plexyglass layer including holes of different diameter (from 4.3 to 0.18 mm) and
depth (from 0.85 to 0.41 mm) between layers containing a breast simulating material. The tomosynthesis system we tested (Hologic) uses a direct detection, 70 µm
pixel, 24x30 cm detector. The acquisition protocol included 15 low dose projections
over a p7.5° angular range and an additional 2D planar view. The projections' data
are reconstructed using a filtered back projection algorithm to give 1 mm-thick
slices. The average glandular dose for the tomosynthesis acquisition was of 1.45
and 1.25 mGy for the planar view. Images were repeated replacing the breast tissue with an equivalent thickness of PMMA. To obtain different realizations of the
non-stochastic noise for each acquisition the details sheet was rotated. To average
the pixel partial volume effect each acquisition was repeated in slightly different
phantom positions. Using an automatic software analysis tool, the contrast to noise
ratio (CNR) of each detail was evaluated.
Results: When the phantom was embedded in breast tissue, in the whole range
of the hole size, the CNR of the tomosynthesis reconstructed images was about a
factor two higher than in the planar mode (P=2E-5). Similar results were obtained
with an equivalent thickness of PMMA (P=3E-4).
Conclusion: In a breast simulating phantom, the tomosynthesis technique allowed
highly significant improvement of CNR respect to the 2D image.
B-046
11:15
Designing an anthropomorphic breast phantom for breast tomosynthesis
S. Rouault, R. Klausz, S. Muller, R. Iordache, H. Souchay; Buc/FR
Purpose: Phantoms for 2D mammography are unrealistic in many ways, and their
usage for performance assessment or optimization of digital breast tomosynthesis
(DBT) systems could be misleading. Their most prominent features usually include
non-realistic local absorption coefficient, planar lesion inserts and absence of
texture, all of which are critical to volumetric imaging of the breast. We propose a
method to obtain anthropomorphic phantoms with adequate absorption, texture
content and lesion-like objects, for a more realistic assessment of the threedimensional imaging performance.
Methods and Materials: The variety of materials present in the breast was initially
mimicked by a careful choice of agar-agar-based gels for glandular and skin tissue,
and animal fat for adipose tissue. The second step was to generate the proper
texture in each region of the breast. This was obtained by assembling each texture
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Methods and Materials: A prototype, research BT system was used. The inclusion criterion for BT examination was women with subtle, but suspicious, findings
of breast cancer selected from digital screening mammography or symptomatic
women with subtle or negative findings on DM, but with suspicious lesions on US.
A total of 65 women with 76 breast cancers were included. BT, DM and US sizes
were measured independently by experienced radiologists without the knowledge
of pathology results, which were used as reference. Scatter plots and linear regression were generated to produce predictive R2 statistics.
Results: The tumor outline could be determined in significantly more cases with
BT (84%) and US (83%) than with DM (51%). BT had the highest size correlation
with pathology (R2 = 0.66), compared to US (R2 = 0.49) and DM (R2 = 0.47).
Conclusion: The study indicates that BT is superior to DM and US for the estimation of breast tumor size.
Scientific Sessions
inside nested moulds at moderate heat. Microcalcification clusters were made of
egg-shell decanted in agar-agar inserts, and injected into the texture, together
with opacities of various shapes. Scoring methods were developed to procure
discriminating imaging performance.
Results: The phantom polymerizes under refrigeration, and remains stable at
ambient temperature over weeks. The range of absorption coefficients attainable
is 0.8-1.2 g/cm3, yielding realistic local absorption properties in the phantom, that
are key for DBT performance assessment. The texture typology is adjustable,
covering all BIRADS densities.
Conclusion: A method for creating phantoms that mimic real breast architecture
characteristics was found, that can be used for the optimization of acquisition
sequence in DBT.
B-047
11:24
Computed tomographic laser mammography (CTLM) as an adjunct to
mammography in dense breasts
J. Qi; TianJin/CN (qijin9817009@163.com)
Purpose: To determine if CTLM can improve mammographic sensitivity in women
with dense breast tissue.
Methods and Materials: Breast density was evaluated by mammography in 155
women scheduled for biopsy or surgery and classified as “heterogeneously dense”,
(BI-RADS Grade 3), or “extremely dense”, (BI-RADS Grade 4). CTLM was then
performed on all patients with dense breasts. The sensitivity and specificity of mammography alone, (M.al), CTLM alone, (CT.al) and CTLM adjunct to mammography
(M+CTLM) were assessed based on pathology findings.
Results: Among 74 grade 3, and 81 grade 4 breasts, pathology revealed 79 malignant and 76 benign lesions. Angiogenesis was seen in 72.15% of malignant and
31.57% of benign lesions (C2=25.558, p = 0.000). In extremely dense breasts the
sensitivity of M.al, versus M+CTLM was 34.40 vs 81.57%. (C2=13.071, p=0.000).
The specificity of M.al versus M+CTLM was 90.48 vs 72.22%. (C2=4.386, p=0.072).
In heterogeneously dense breasts the sensitivity of M.al versus M+CTLM was 68.29
vs 95.34% (C2=11.131, p=0.001). The specificity of M.al versus M+CTLM was
85.00 vs 55.26% (C2=8.288, p=0.004). The sensitivity of CTLM alone in extremely
vs heterogeneously dense breasts was 74.40 vs 85.00% (C2=0.446, p=0.504) and
specificity 71.00 vs 61.00%, (C2=0.000, p=1.000).
Conclusion: Because CTLM, which detects angiogenesis, is not affected by
breast density, its use as an adjunct to mammography could improve the present
low sensitivity of mammography in dense breasts.
B-048
11:33
Quantitative research of radiation dose comparison using clinical data on
digital mammography
C. Kohama1, A. Yoshida2, M. Matsumoto3, Y. Shidahiga4; 1Hatsukaichi/JP,
2
Miharashi/JP, 3Oosaka/JP, 4Fukuoka/JP (dandelion@do.enjoy.ne.jp)
Purpose: We analyzed the relation between the radiation dose and the conditions
(the focus, the filter and kV) using clinical mammography images and phantoms.
Methods and Materials: Samples were 7,100 clinical images taken by GE Senograph DS with auto-mode (2006.5-2007.2). Conditions (the focus, the filter and
kV) and the radiation dose were analyzed in respective breast thickness in terms
of two modes, Contrast and Standard.
Results: In the case of breast thickness of 2-4 cm, it was likely that Mo/Rh was
selected on the auto mode both of Contrast and Standard used clinically normally.
On the other hand, Rh/Rh was selected in the case of 5 cm or more. In comparison
to dose-limiting value of EUREF (European Reference Organization for Quality
Assured Breast Screening and Diagnostic Services), the dose was acceptable at
any thickness on the standard mode.
Conclusion: On FPDM both Mo/Rh and Rh/Rh were selected in the case of any
thinner thickness. This result leads to prove our past research on FPD mammography and suitable spectrum, concluding that S/N ratio had not changed in the range
of 2-6 cm of BR12 at the same value of average mammary gland dose. The thicker
the thickness became, the more the radiation dose was measured on screen-film,
but the radiation dose was decreased on FPDM. As this result corresponds with
the past result (when Mo/Mo is more than 6 cm, Rh/Rh is better than Mo/Rh), it is
supposed that the auto focus/filter was selected logically.
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B-049
11:42
Photon-counting single-shot dual energy breast tomosynthesis
M. Lundqvist1, M. Åslund1, M. Hemmendorff1, B. Cederström2, M. Danielsson2;
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Solna/SE, 2Stockholm/SE (magnus.aslund@sectra.se)
Purpose: In mammography, there is room for improving sensitivity and specificity,
and three-dimensional imaging has been proposed as an improvement to conventional projection mammography. A method for photon-counting single-shot dual
energy breast tomosynthesis is presented and evaluated physically.
Methods and Materials: Within the EU-funded HighRex-project, a tomosynthesis
system based on a photon-counting scanning multi-slit technology from Sectra
(Solna, Sweden) is being developed. The system features contrast-enhanced singleshot dual energy and optimisation of the photon-energy spectrum is performed with
respect to both anatomical and statistical noise. In a 2D-environment a prototype is
evaluated using an anatomical clutter phantom with iodinated contrast agent. Clinical
trials have been initiated and a quality-control protocol is being evaluated.
Results: Single-shot dual energy imaging provides short exposure times, which
reduces the risk of artifacts in the reconstructed images. The boosted tomographic
angle from using a rotational scan motion makes it possible to narrow the detector,
which further reduces the exposure time down to approximately 2 seconds. The
combination of the scatter rejection from the scanning geometry and the photoncounting technique providing a maintained DQE for the low-dose projection images
results in an improved dose efficiency and image reconstruction. With a 40-45 kVp
tungsten spectrum filtered with 2 mm aluminium, the smallest visible phantom contrasts were reduced by half with dual energy compared to conventional images.
Conclusion: The single-shot photon-counting technique has the potential of providing artifact free images at very low doses. The contrast-enhanced dual energy
increases the conspicuity of simulated lesions.
B-050
11:51
Automated volumetric breast density assessment from digital
mammography: Theory and validation
K.W. Hartman1, J. Marshall1, A.P. Smith2; 1Santa Clara, CA/US, 2Bedford, MA/US
(julian.marshall@hologic.com)
Purpose: To assess an automated algorithm that computes volumetric breast
density from digital mammograms.
Methods and Materials: An algorithm that computes breast density from digital
mammograms (DM) was developed and evaluated. The algorithm does not require
calibration markers or other objects in the mammogram, but rather uses known
physics principles, technical equipment details, and compressed breast thickness
for the calculations. It computes breast volume, fibroglandular tissue volume and
percent glandularity. A number of clinical validations were performed: Comparisons
were made between the algorithm output between left and right breasts; and
comparisons between currents and priors. Finally, breast density in 2230 patients
using both DM and breast MRI images were compared.
Results: The Pearson correlation coefficient (PCC) was used to measure the
correlation for the volume of fibroglandular tissue Vfg between currents and priors
and had a value of 0.97. The PCC for Vfg between left and right breasts was 0.92.
The PCC for Vfg between CC and MLO views was 0.93. The correlation coefficient
for fibroglandular tissue volume between DM and MRI was 0.89. All the metrics
studied showed that the algorithm provides internal consistency and reasonable
correlation to the gold standard of segmenting MRI images to measure the volume
of fibroglandular tissue.
Conclusion: The automated algorithm provides self consistent methods of measuring volumetric breast density, when comparing CC to MLO and left and right breasts.
Comparisons to breast density as measured by MRI also show good correlation.
Scientific Sessions
10:30 - 12:00
Room G/H
Head and Neck
Nerves, teeth, eyes and ears
Moderators:
J. Qi; Tianjin/CN
B. Verbist; Leiden/NL
B-051
10:30
Trigeminal neuralgia due to neurovascular compression: Neural
microstructural changes measured by high-resolution diffusion tensor
imaging
J. Lutz, J. Linn, J.H. Mehrkens, N. Thon, K. Seelos, H. Brückmann,
M. Holtmannspoetter; Munich/DE (juergen.lutz@med.uni-muenchen.de)
Purpose: The aim of the study was to preoperatively evaluate microstructural
changes of the trigeminal nerves in patients with trigeminal neuralgia (TN), due
to neurovascular compression, using a high-resolution diffusion tensor imaging
sequence (DTI) and a 3D fast imaging employing steady-state acquisition sequence
(3D FIESTA).
Methods and Materials: A total of 20 patients with TN and evidence of a neurovascular contact were examined prior to surgical decompression using a 3.0 T MR
scanner (Signa HDx, GE, USA) in combination with an eight-channel head coil. We
used a single shot DTI EPI sequence along 15 different diffusion directions with
a b-value of 1,000 s/mm2 and a slice thickness of 2 mm. Automated fiber tracking
was used to evaluate fiber orientation. For anatomic correlation, a 0.6 mm isotropic
3D FIESTA sequence was acquired for coregistration with the functional DTI maps.
The fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) were
studied. The DTI indices were correlated with surgical and clinical findings
Results: FA was significantly (P 0.05) lower on the affected side (mean 0.3)
compared to the contralateral side (mean 0.47). ADC was higher on the ipsilateral
side compared with the contralateral side, but did not reach statistical significance.
Detection of the trigeminal nerve was improved by the coregistration with the 3D
FIESTA sequence.
Conclusion: These findings suggest that DTI allows the identification of anisotropic changes between normal nerve tissue and affected trigeminal nerves. The
coregistration of an anatomic 3D FIESTA and DTI is excellent for the delineation
of the cisternal segments of the trigeminal nerves.
B-052
10:39
Chronic facial pain: What contribution can MRI make?
M. Tumen, N. Saeed, S.J. Golding; Oxford/UK (mustafa.tumen@wolfson.ox.ac.uk)
Purpose: Chronic facial pain is a debilitating condition and represents a diagnostic
challenge. Clinical investigation includes excluding underlying disease, but incidence
of lesions is perceived to be low. This study evaluated the role of comprehensive
MRI in investigation.
Methods and Materials: A total of 91 patients (36 M, 55 F) underwent MRI of
the brain and face on a 1.5 Tesla system, using a standard protocol including
trigeminal nerve territories in addition to cerebral and facial structures. Data collection included presenting symptomatology, and site and nature of any lesions.
Evaluation of clinical significance included the effect of subsequent treatment. A
patient survey was undertaken to establish patients’ perceptions of the contribution
of MRI to their pain management.
Results: Of 91 patients, 16 (17.6%) had a positive finding of disease, but only 6
of these (6.5%) had disease that could be directly implicated in pain, including
cerebellopontine angle masses and basilar artery impression. Other patients had
intracranial (2) or extracranial lesions (8) not directly related to symptoms, including sialadenitits and dental cysts. There was a high incidence of sinus mucosal
thickening (33 patients, 36.3%), but no direct relationship with symptoms. A total
of 32 patients responded to survey; 29 (91%) felt MRI was valuable and 22 (69%)
that it had helped with their management. Patients allocated a generally high score
to their care in MRI.
Conclusion: MRI has a positive effect on treatment in only a small number of patients, but has value in excluding significant disease and the investigation appears
to be strongly appreciated by patients.
10:48
3 T MRI 3D FIESTA demonstrating branches of intraparotid facial nerve,
parotid duct, and relation with parotid tumors
C. Li, B. Ai, Y. Li, L. Wu; Jinan/CN (lichuanting@yeah.net)
Purpose: To investigate the usefulness of 3 T MR imaging 3D FIESTA in evaluation intraparotid components of the facial nerve and parotid duct, and compared
with surgical findings.
Methods and Materials: The 3D FIESTA sequences were used at 3 T MRI with a
head coil. The most clinically useful images were acquired at parameters of 4.9/1.5
(TR/TEeff) a flip of 55°, a field of view of 18 to 20 cm, a matrix of 512 x 320, an
axial plane, no gaps, and a section thickness of 1.0 mm. Postprocessed multiplanar
images were obtained with AW sdc 4.3 workstation. 20 healthy subjects and 24
patients with benign parotid tumours were studied. Parotid ducts facial nerves and
tumors were identified on these images. The relationship of the tumors to the facial
nerves was confirmed at surgery.
Results: Facial nerves appeared as linear structures of low intensity. The main
trunks and cervicofacial and temporofacial divisions of the facial nerves were identified bilaterally in 100%. Parotid ducts appeared as structures of high intensity on
multiplanar images (100%). The relationships of the tumors to the facial nerves
were correctly diagnosed in 23 of 24 cases (95.8%).
Conclusion: 3 T MR 3D FIESTA imaging depicts the extracranial facial nerve
and the parotid duct, and is useful for preoperative evaluation of parotid gland
tumors.
B-054
10:57
The intermediate nerve in the cerebellopontine angle: Visualisation using
3 T MRI
H.P. Burmeister, P.A.T. Baltzer, A. Hadlich, P. Schmidt, G.F. Volk,
O. Guntinas-Lichius, H.-J. Mentzel, W.A. Kaiser; Jena/DE
(hartmut.burmeister@med.uni-jena.de)
Purpose: The aim of this study was to evaluate the identifiability of the intermediate nerve in the cerebellopontine angle and the inner auditory canal using 3 T-MRI
with respect to spatial differentiation from the facial nerve, vestibulocochlear nerve,
and vascular loops.
Methods and Materials: We examined 54 intermediate nerves in 27 healthy
subjects. The layer thickness of the axial constructive interference in steady-state
3DFT (CISS) sequences was 0.4 mm (TR 12.18 ms, TE 6.09 ms, 512 x 512 matrix,
isotropic voxels) using an 12-channel head coil. Two independent radiologists evaluated the identifiability of the nerves, roots, rootlets, and the image quality using an
ordinal categorisation. Concerning the identifiability of the nerve and the image
quality we evaluated the inter-rater reliability using kappa statistics.
Results: Statistical testing showed that an identifiability of the intermediate nerve
and spatial separation from the facial nerve, vestibulocochlear nerve, and vascular
loops was possible in 22.2% with limitations and without limitations in 35.2%. So it
was possible to depict at least one root in 57.4% of all cases. A depiction of rootlets
was unlikely and merely possible in 2.8%. The strength of inter-rater agreement
was very good concerning the identifiability (+ = 0.92) and good relating to image
quality (K = 0.65).
Conclusion: 3 T-MRI enables for the first time the identifiability of the intermediate
nerve in the cerebellopontine angle and the inner auditory canal in a majority of
cases. Therefore an assessment of the intermediate nerve becomes possible for
instance in preoperative planning.
B-055
11:06
CT and MRI signs in biphosphonate-associated osteonecrosis of the jaws:
A tool for improving diagnostic accuracy
S. Bisdas1, I. Burck2, I. Xida3, N. Chambron-Pinho2, M.G. Mack2; 1Tübingen/DE,
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Frankfurt a. Main/DE, 3Göttingen/DE
Purpose: To characterize the radiologic appearance of biphosphonate-associated
osteonecrosis (BAON) and to evaluate for distinguishing signs from radiationinduced osteonecrosis (RION) and osteomyelitis (OM).
Methods and Materials: We reviewed panoramic radiographs/CT/MR scans of 42
patients with biopsy-proven BAON. Periosteal reaction, cortical erosion, sclerosis,
fragmentation, destruction of the trabecular bone and sequestrum, lymphadenopathy and presence of soft-tissue mass were evaluated. We compared them
with panoramic radiographs/CT/MR scans of eight patients with RION and eight
patients with OM.
Results: Osteonecrosis was histologically identified in the mandible of 28 patients, maxilla of 8 patients and in both jaws of 6 patients. Radiographs showed
radiopaque and radiolucent areas in all BAON patients. Expansile osteolysis with
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central sequestra (CT scans) resulted in a “bone-within-bone” sign and were highly
suggestive of BAON (83% of the patients), while they did not appear either in RION
or OM cases. Nearly all RION cases showed fragmentation and trabecular bone
collapse. Of all the BAON patients, 60% showed involvement of the mandibular canal
resulting in a “nerve road mapping” sign, which did not appear in RION/OM cases
and 50% of the BAON patients demonstrated marked periostal bone proliferation
resulting in a “ground-glass brim” sign. OM patients showed only reactive sclerosis.
A “pseudotumor” sign (MR scans) with maxillary sinus involvement was observed in
ten BAON patients and in two RION patients. Reduction of the marrow space with
T1-weighted hypointensity and sclerosis were indicative of unexposed diseased
bone. Reactive lymphadenopathy was not a BAON-specific finding.
Conclusion: The aforementioned imaging signs, in an appropriate clinical setting,
should alert to the possibility of BAON.
B-056
11:15
Bone density and periodontal tissue alteration of dental implant sites:
A cone beam CT study
D.M. Preda1, M. Hedesiu2, C. Popita1, A.R. Ionescu1, M.F. Baciut2, G. Baciut2;
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Bucharest/RO, 2Cluj-Napoca/RO (diana_monica_preda@yahoo.com)
Purpose: This study was designated to evaluate variations in bone density of
designated endosseous implant sites using cone beam computed tomography
(CBCT) and to assess if perodontal tissue changes are related to bone density
variations.
Methods and Materials: A total of 85 potential sites for implant placement in the
jaws from 43 patients were used. Bone density was assessed in a standardized
implant area superimposed on CBCT images and the variation was evaluated using the Misch’s bone density classification. Periodontal tissue changes (involving
delineation of lamina dura, crater defect and furcation involvements) were assessed
on the CBCT images. The clinical examination of periodontal tissue, including clinical attachment loss, pocket depth, plaque, papilla bleeding and tooth mobility, was
imaging related and established four degrees of periodontal disease.
Results: CBCT results demonstrated that bone densities may vary when different
areas of a designated implant site are compared. Regarding the correlation between
the bone density and the periodontal tissue changes, strongly significant differences
(P 0.0001) were found between the superior bone densities (D1 and/or D2) and
healthy or slightly affected periodontal tissue. The inferior Misch bone densities (D3
and/or D4) are correlated with medium or severe periodontitis (P 0.0001).
Conclusion: CBCT could be considered an alternative diagnostic tool for preoperative jaw bone qualitative assessment (including bone density evaluation correlated
or not with morphological changes), especially since the reported radiation dose
is minimal.
B-057
11:24
Radio frequency-induced heating near fixed orthodontic appliances during
magnetic resonance imaging at 3.0 Tesla
F. Henes, J. Kemper, M. Kaul, P. Begemann, M. Feddersen, G. Adam, B. Kahl-Nieke,
A. Klocke, M. Regier; Hamburg/DE (f.henes@uke.uni-hamburg.de)
Purpose: The purpose of this study was to assess the radiofrequency (RF)-induced
heating near fixed orthodontic appliances during the acquisition of three different
sequences in high-field magnetic resonance imaging (MRI) at 3 Tesla.
Methods and Materials: Ten commonly used fixed orthodontic appliances were
investigated at a 3 Tesla unit (Intera, Philips Medical Systems, Best, The Netherlands) utilizing a head phantom simulating the in vivo intraoral situation. A T1w
spin-echo (TR/TE 150/25 ms; FOV 350 mm; slice thickness 4 mm; SAR 3.5 W/kg),
T1w turbo spin-echo (TR/TE 5,995/92 ms; FOV 350 mm; slice thickness 3 mm; SAR
4 W/kg) and T1w gradient-echo (TR/TE 4.5/1.7 ms; FOV 350 mm; slice thickness
5 mm; SAR 1.9 W/kg) sequence were acquired in axial orientation. For continuous temperature measurement, a dedicated four-channel fluoroptic thermometry
system (Fotemp 4, Optocon, Dresden, Germany) was used. For each orthodontic
appliance, temperature probes were placed at three predefined sites in order to
perform temperature measurements during MR imaging. The fourth temperature
probe was fixed to the neck of the head phantom and served as the reference.
Mean temperature alterations were determined for all appliances.
Results: Temperature elevations ranged from -0.3° to 0.2° and were negligible for all
orthodontic appliances investigated. There was no difference in mean temperature
alteration among the three imaging sequences performed.
Conclusion: Based on the results of an experimental setting, the radiofrequencyinduced heating near orthodontic appliances does not seem to be a concern during
MRI of patients undergoing orthodontic treatment.
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B-058
11:33
Diagnostic performance of CT for detection of open globe injury in
patients with suspected orbital trauma
S. Kim, J. Lee, B. Choi, S. Kim, J. Choi, H. In, Y. Lee, S. Kim; Seoul/KR
Purpose: To evaluate the diagnostic performance of orbit CT for the detection of
open-globe injury in patients with suspected orbital trauma.
Methods and Materials: Among 392 consecutive patients who underwent CT for
suspicion of orbital trauma, this study enrolled 28 patients with unilateral open-globe
injury diagnosed by surgery and 28 controls without orbital trauma. Two masked
readers evaluated the following characteristics of the insulted globe on CT images:
the change of the anterior chamber depth (ACD), contour irregularity, volume loss,
dislocated lens and intraocular hemorrhage. A generalized estimating equations
analysis was used for statistical analysis. Sensitivity, specificity and diagnostic
accuracy were also obtained. Another radiologist measured the ACDs of the two
globes without lens dislocation and then compared the ACD difference of the two
globes to figure out how the decreased ACD of the insulted globe influences the
diagnostic performance on ROC analysis.
Results: The sensitivity, specificity and diagnostic accuracy of CT findings were
57, 87 and 78% for decreased ACD, 68, 89 and 78% for contour irregularity, 50,
100 and 75% for volume loss, 53, 100 and 76% for dislocated lens, and 48, 100
and 74% for intraocular hemorrhage. An ACD decrease of more than 0.4 mm
demonstrated the best diagnostic performance (Az = 0.918) with sensitivity of 83%
and specificity of 100% (P = 0.0001).
Conclusion: Although the specificities of the CT findings of open-globe injury
were very high, the sensitivities were inadequate to be relied on. However, an ACD
decrease of more than 0.4 mm of the insulted globe can add valuable information
with high diagnostic performance for open-globe injury.
B-059
11:42
Usefulness of 3D FIESTA imaging to evaluate the primary detachment of
retina
Q. Chen, Z. Wang, J. Xian, B. Yang, F. Yan, Q. Xu; Beijing/CN
(cjr.yangbentao@vip.163.com)
Purpose: The primary detachment of retina (RD) was visualized limitedly on FSE
T1WI or T2WI because the signal of subretinal fluid was similar to the vitreous. 3DFIESTA is a fast imaging sequence with high spatial resolution and good contrast
between water and other organizational structures. The sensitivity of 3D-FIESTA
for the visualization of primary RD and MRI findings were discussed.
Methods and Materials: MR imaging was performed in 31 patients with myopic
eyes and primary detachment of retina including axial FSE T1WI, T2WI and
3D-FIESTA. With or without RD, the shape and signal of the subretinal fluid were
assessed in three different contrast weighting images.
Results: In total, 67.7, 74.2, 100% of RD were showed, respectively, in FSE T1WI,
T2WI, 3D-FIESTA in 31 myopic eyes with primary RD. RD appeared as V-shape
in 16 cases, arc-shape in 15 cases. The subretinal fluid demonstrated isointense
signal compared with the vitreous in 26 cases, slightly hyperintense signal in three
cases, hyperintense signal in two cases on T1-weighted imaging, and isointense
signal in 16 cases, hyperintense signal in 15 cases on T2-weighted imaging, and
isointense signal in 19 cases, hypointense signal in 11 cases, hyperintense signal
in one cases on 3D-FIESTA images. The detached retina displayed glossy thin wire
shape in 16 cases and wave shape in 15 cases, and the display rate was 54.8,
64.5,100% on FSE T1WI,T2WI and 3D-FIESTA, respectively.
Conclusion: 3D-FIESTA was the optimal sequence to detect primary RD with
high sensitivity.
B-060
11:51
Bionic ear imaging: A dose comparison study between conebeam
computed tomography and multislice computed tomography
N. Faccioli, M. Barillari, R. Cerini, R. Pozzi Mucelli; Verona/IT (nfaccioli@sirm.org)
Purpose: Patients treated with bionic ear implants are often children who need
a strict follow-up by functional and radiological examinations, in particular MSCT
scans. Dental volumetric cone beam CT (CBCT) had been suggested as a reliable diagnostic technique to acquire images of temporal bone with low ionizing
radiation dose and costs. The aim of this work was to assess, in terms of radiation
dose and image quality, the possibility to evaluate patients with bionic ear implants
by CBCT.
Methods and Materials: One hundred patients (medium age 23 y, range 7-43) implanted with Vibrant SoundBridge at the round window were followed up with CBCT
(85 patients) and MSCT (15 patients). We measured the averaged tissue-absorbed
doses both during a MSCT and a CBCT examination; each scan was focused on
Scientific Sessions
10:30 - 12:00
Room I
Vascular
SS 215
Vessel wall, plaque imaging and MRA
Moderators:
M.G.M. Hunink; Rotterdam/NL
I.P. Vulev; Bratislava/SK
B-061
10:30
Evaluation of atherosclerotic plaque composition in a healthy elderly
population: The Rotterdam study
Q.J.A. van denBouwhuijsen, P.A. Wielopolski, S. Rozie, A. Hofman, G.P. Krestin,
J.C.M. Witteman, A. van der Lugt; Rotterdam/NL
(q.vandenbouwhuijsen@erasmusmc.nl)
Purpose: Plaque vulnerability to rupture is related to the composition and morphology of the atherosclerotic plaque. With multiple contrasts, MRI can provide
an effective mean to identify and quantify different components of atherosclerotic
plaque in the carotid arteries.
Methods and Materials: This study is performed within the framework of the Rotterdam study, a large ongoing population-based study performed in healthy subjects
aged 45 years and older. Participants with asymptomatic carotid atherosclerosis
defined by ultrasound were studied. We acquired MRI scans with multiple contrasts
using a 1.5 Tesla MRI scanner and a bilateral surface coil. All images were linear
registered. Presence of plaque, presence of different plaque components (calcification, intraplaque haemorrhage, lipid rich necrotic core (LR/NC), fibrous tissue),
predominant plaque component and maximal plaque thickness were determined
using previously defined MRI criteria.
Results: A total of 200 subjects (age range 56.4-98.5 years; 47% men) were
studied. A total of 6% of the studies were excluded due to low image quality. Forty
carotid arteries were normal. In 336 carotids (89%) a plaque was present with a
plaque thickness of 3.4 p 1.1 mm. Calcifications, intraplaque haemorrhage and LR/
NC were respectively seen in 69%, 27% and 23% of the plaques. The predominant
component was fibrous tissue in 52%, calcification in 28%, intraplaque haemorrhage
in 12% and LR/NC in 8% of the plaques.
Conclusion: Carotid plaque evaluation in the healthy population is feasible. Different components of the plaque can be identified. Intraplaque haemorrhage and
LR/NC, which are considered constituents of the vulnerable plaque, are present
predominantly in 20% of asymptomatic atherosclerotic carotid disease.
B-062
10:39
The carotid vulnerable plaque analyzed by using multidetector-row CT
angiography
L. Saba, R. Sanfilippo, R. Montisci, G. Mallarini; Cagliari/IT (lucasaba@tiscali.it)
Purpose: Atherosclerosis of extracranial carotid arteries is the most important
cause of stroke. Our purpose was to evaluate the MDTCA plaque characteristics
for vulnerability in a cohort of 630 patients.
Methods and Materials: A total of 630 patients with 1,260 carotids were retrospectively analyzed. Plaque morphology (regular versus irregular), the type of the
plaque (fatty, mixed and calcified), presence of ulcerations, fissured fibrous cap
and thrombosis were evaluated. The degree of stenosis (according to the NASCET
criteria) was also measured. We correlated MDCTA data with the presence of ischemic events. Statistic analysis was performed to determine if an interaction existed
between specific plaque characteristics and presence of ischemic events.
Results: A history of symptomatic ischemic episode was present in 239 patients. We
found a positive correlation between the presence of fatty plaque and symptomaticity (P 0.01), ulcerations and symptomaticity (P 0.01). FFC and symptomaticity
(P 0.05) and irregular morphology and symptomaticity (P 0.05).
Conclusion: The result of our study indicates that some plaque characteristics are
correlated with the presence of ischemic episodes; in particular, fatty plaque and the
presence of ulceration are significantly associated. We think that these conditions
may identify a vulnerable plaque, regardless of the degree of stenosis.
B-063
10:48
Does the amount of calcifications represent the total plaque burden in the
carotid artery: An analysis with multidetector CT angiography
S. Rozie, D. Vukadinovic, L. van denBorne, W.J. Niessen, D.J.W. Dippel,
A. van der Lugt; Rotterdam/NL (s.rozie@erasmusmc.nl)
Purpose: To investigate the relationship between atherosclerotic plaque volume and
the volume of calcifications in the carotid artery. We hypothesize that calcification
volume does not represent the total plaque burden in the carotid bifurcation.
Methods and Materials: Plaque volume and calcification volume of the atherosclerotic carotid plaque was measured in 120 patients (age 67.1 p 10.5 years, 78
males) with cerebrovascular symptoms and with bilateral atherosclerotic disease
in the carotid bifurcation. Scanning was performed on a 16-slice MDCT scanner
(Siemens, Sensation 16, Erlangen, Germany). A novel semi-automatic method was
used to segment the plaque and the calcifications in the carotid bifurcation.
Results: The mean plaque volume of the 240 plaques was 900 p 674 mm³ and
the volume of the carotid calcifications was 139 p 175 mm³. The plaque volume
in the symptomatic artery was not significantly different from the plaque volume
in the asymptomatic artery. The correlation between calcified volume and plaque
volume was moderate (R² = 0.32). The volume of carotid calcifications was almost
seven times smaller than the plaque volume (calcified plaque volume = 7.0 + 0.15 *
total plaque volume). The correlation between plaque volume and calcified volume
in the asymptomatic carotid arteries was weaker than in the symptomatic carotid
arteries (R² = 0.20 and R² = 0.49, respectively).
Conclusion: There is no strong relationship between the volume of carotid calcifications and atherosclerotic carotid plaque volume. Carotid calcifications cannot
be used as an estimation of atherosclerotic carotid plaque burden.
B-064
10:57
Atherosclerotic plaque ulceration in the internal carotid artery is
associated with cortical ischemic stroke
P.J. Homburg, T. Jansen, S. Rozie, T.T. de Weert, D.W.J. Dippel, A. van der Lugt;
Rotterdam/NL (P.Homburg@erasmusmc.nl)
Purpose: Atherosclerotic plaque ulceration is a marker of previous plaque rupture
which may lead to thromboembolism. We hypothesized that plaque ulceration is
more prevalent in ischemic cortical strokes than in other stroke subtypes.
Methods and Materials: Using MDCTA, we evaluated images of 752 patients (56%
male, mean age 63 p 13 years) with cerebrovascular symptoms in the anterior
cerebral circulation. Plaque ulceration was defined as extension of contrast material beyond the vascular lumen into the surrounding plaque. Strokes were clinically
classified in cortical stokes, lacunar stokes and amaurosis fugax (AF). Exclusion
criteria were: cardiac embolism (N=76), other stroke etiology (N=21) and poor image
quality (N=2). Chi-square test was used for statistical analysis.
Results: Atherosclerotic disease was present in the symptomatic carotid artery
in 72%. Presence of plaque ulceration was significantly higher in the symptomatic
carotid artery in patients with cortical strokes than in patients with lacunar strokes
(21 vs. 7%; p 0.001) and AF (21 vs. 9%; p 0.01). There was a trend towards a
higher prevalence of plaque ulceration in the symptomatic carotid artery than the
asymptomatic artery of patients with cortical strokes (21 vs. 15%; p=0.06). No difference was found in prevalence of ulceration between symptomatic and asymptomatic
arteries in patients with lacunar stroke (7 vs. 8%) or AF (9 vs. 11%).
Conclusion: Prevalence of plaque ulceration was higher in the symptomatic carotid
artery in patients with cortical strokes compared to patients with lacunar strokes and
AF. Plaque ulceration was more frequent in the symptomatic carotid artery compared
to the asymptomatic carotid artery in patients with cortical strokes.
B-065
11:06
Blood pool-enhanced magnetic resonance angiography for the
characterisation of carotid plaque composition: Correlation with
endarterectomy specimen
S. Tartari1, R. Rizzati1, R. Righi1, K. Capello1, R. Soverini2, E. Tsolaki3, F. Mascoli2,
G. Benea1; 1Lagosanto/IT, 2Ferrara/IT, 3Bologna/IT (s.tartari@alice.it)
Purpose: To assess accuracy of high-resolution 3-dimensional imaging technique
performed after contrast enhanced magnetic resonance angiography (CE-MRA) for
evaluation of carotid plaque composition, in comparison to surgical specimen. To
measure the signal intensity (SI) of different components of plaque (soft, fibrous,
calcific) in post-contrast imaging.
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the temporal bone with the smallest field-of-view and low radiation dose protocol.
For image quality, we obtained data about slice thickness, high and low contrast
resolution, and noise by the use of an AAPM CT performance phantom.
Results: Patients who underwent MSCT received a three times higher radiation
dose than patients who performed a CBCT scan (0.28 vs 0.11 mSv). The anatomical structures of the middle ear were better showed by MSCT, because of high
contrast resolution, but CBCT provided images adequate to evaluate the correct
position of the implants.
Conclusion: Because of the low radiation dose and the good quality of the images,
CBCT could be considered a correct radiological technique for the postoperative
examination of patients with bionic ear implants.
Scientific Sessions
Methods and Materials: Between January and June 2008, 75 consecutive patients
underwent CE-MRA of head and neck vessels on a 1.5 T unit with parallel imaging
(SENSE), with administration of a blood pool contrast agent (BPA) (Vasovist, Bayer
Schering Pharma AG, Berlin, Germany). After dynamic first-pass (FP) imaging,
all patients were evaluated in steady-state (SS) with an axial T1-weighted highresolution isotropic volume examination sequence (THRIVE, voxel size 0.5 mm). In
all patients, we analyzed plaque morphology and composition; moreover, based on
SI, carotid plaques in SS imaging were classified into one of three types (predominant component): soft tissue, fibrous or calcification. MR findings were compared
with endarterectomy specimen (visual inspection) of 21/28 patients who underwent
treatment (7 patients treated with carotid stenting).
Results: MR was able to discriminate between plaques predominantly soft from
fibrous-calcification; 6/8 patients with soft (unstable) plaque were correctly identified
by MR (k=0.68). Mean SI value of soft plaque was measured 34.7.
Conclusion: High-resolution isotropic imaging in SS for evaluation of carotid plaque
composition is a valuable tool for assessment of carotid plaque composition, adding significant value to dynamic CE-MRA. In the detection of soft plaque, there is
good agreement between BPA-enhanced MRA and surgical specimen. Further
investigations with histopathological correlation are needed.
B-066
11:15
Delayed enhancement of carotid atherosclerotic plaques as a marker of
inflammation and instability: A magnetic resonance study using bloodpool contrast agent
M. Anzidei, B. Cavallo Marincola, A. Napoli, P. Di Paolo, C. Catalano,
R. Passariello; Rome/IT (michele.anzidei@gmail.com)
Purpose: To evaluate the association between plaque inflammation, instability
and delayed enhancement at MR imaging after the administration of a blood-pool
contrast agent (BPCA).
Methods and Materials: Blood-pool enhanced MRI was performed in 20 patients
with steno-occlusive disease of carotid arteries, candidate to endoarterectomy. All
examinations were performed on a 1.5 T unit after the administration of 0.03 mmol/
kg body weight of BPCA (Gadofosveset Trisodium) using high-resolution T1-w
3D GRE sequences (TR 12,TE 2.35,Voxel size:0.7*3, Matrix 512 x 512, TA 325
s) acquired at the steady-state phase. Plaque enhancement was qualitatively
evaluated on a 4-point scale (1-absent, 2-poor, 3-intermediate, 4-high); clinical
indexes of inflammation and histological results were compared with MRI findings
to evaluate eventual association.
Results: MR examinations were successfully performed in all patients; endoarterectomy was performed at least 1 week later. Plaque enhancement on delayed
imaging was evaluated in 20 arteries: it was absent in 3 vessels, poor in 5, intermediate in 2 and high in 10. Histological findings of inflammation were identified in
13 out of 20 surgical specimens. Significant correlation between plaque enhancement and histological signs of inflammation was evidenced; a further correlation
between clinical indexes of flogosis and blood-pool enhanced MRI findings was
also demonstrated.
Conclusion: The correlation between blood-pool enhanced MRI findings, histological analysis and clinical indexes represents a potential non-invasive marker
for the evaluation of high-risk plaque inflammation that could be used to plan
patients management.
B-067
11:24
Imaging of carotid artery plaques: Correlation between 18 F-FDG PET and
MRI findings
R.M. Kwee, J.E. Wildberger, G.J.J. Teule, J.M.A. van Engelshoven, W.H. Mess,
M.E. Kooi; Maastricht/NL (rmkwee@gmail.com)
Purpose: Noninvasive plaque imaging by 18F-FDG PET and MRI may be used
to identify vulnerable plaques (i.e., plaques which have a high tendency to cause
ischemic events). 18F-FDG PET is able to assess the severity of inflammation in
carotid plaques, whereas MRI allows evaluation of morphological and compositional
plaque characteristics. The purpose of this study was to assess whether 18F-FDG
PET and MRI findings correlate or have to be seen as two complementary (separate) imaging modalities.
Methods and Materials: Thirty patients with symptomatic carotid atherosclerosis
underwent standard 18F-FDG PET and a dedicated MRI protocol (time interval
between both imaging modalities: 5.4 p 3.5 days). Correlations between findings
of both imaging modalities were evaluated by Spearman rank correlation analyses
(strong correlation: R of 0.8 or greater).
Results: Spearman rank correlation analyses did not reveal strong significant
correlations between mean and maximum 18F-FDG standard uptake value (SUV)
of the plaque, normalized for mean blood SUV, and any of the MRI-assessed
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parameters. There was only a weak-to-moderate correlation between maximum
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F-FDG uptake and maximum lipid-rich necrotic core/hemorrhage area of the
plaque on MRI (Spearman R = 0.360, P = 0.05).
Conclusion: There is no strong correlation between 18F-FDG PET and MRI-assessed morphological and compositional plaque characteristics. At present, 18F-FDG
PET and MRI should be regarded as two complementary imaging modalities. Future
prospective longitudinal studies will determine whether 18F-FDG PET or MRI (or a
combination of both) is most effective in identifying vulnerable plaques.
B-068
11:33
Evaluation of activity in Takayasu’s arteritis (TA) with MR angiography
(MRA) using intravascular contrast media (VASOVIST)®
M. Papa, F. De Cobelli, E. Schiani, L. Dagna, M. Sabbadini, A. Del Maschio;
Milan/IT (papa.maurizio@hsr.it)
Purpose: Evaluation of disease activity in patients affected by Takayasu’s arteritis
(TA) is a medical challenge. Correct evaluation of disease activity has relevant therapeutic implications; however, this is now based only on clinical ground features. At
present no imaging technique can really differentiate between active (AD) and non
active disease (NAD). Vasovist® is a new intravascular blood-pool contrast agent
recently introduced. In this study, we sought to investigate a correlation between
clinical activity and enhancement in vascular wall in patients with Takayasu’s disease
using MRA with VASOVIST.
Methods and Materials: 20 patients with TA underwent whole body MRA; supraaortic trunks, visceral vessels, thoracic and abdominal aorta were studied. We
used VASOVIST, correlating the enhancement of vessel wall thickening with the
clinical suspect of disease activity and laboratory values as eritrosedimentationrate
(ESR). ECG-triggered BB sequences, first pass and HR steady-state imaging were
obtained in all patients.
Results: 11 patients had a clinically AD, whereas the 9 remaining had NAD.
Comparing the enhancement of thickenings in AD and NAD patients’ significant
difference was found. The enhancement of AD vessel wall was significantly higher
than NAD vessel walls (89.3 and 17.9% of increment respectively: p=0.00019).
Even a statistical correlation between enhancement and ESR was observed
(r=0.58; p 0.0014).
Conclusion: AD patients had vivid enhancement of the outer layer of the thickened
vessel wall. This can be considered the imaging expression of the adventitia’s
layer inflammation in active Takayasu’s disease, while NAD patients had no wall
enhancement, even in case of old wall thickenings.
B-069
11:42
Role of the high resolution magnetic resonance vessel wall imaging at
3 Tesla for identifying activity of Takayasu arteritis
X. Liu, J. Xu; Shanghai/CN (renjixjr@gmail.com)
Purpose: To analyze the value of the high resolution magnetic resonance vessel wall
imaging at 3 Tesla for more accurate identifying activity of Takayasu arteritis (TA).
Methods and Materials: Twenty six patients who fulfilled the diagnostic criteria for
TA of the American College of Rheumatology were examined for supraortic vessels
by high resolution MR vessel wall imaging on a 3.0 T scanner (according to the classification of Lupi-Herrea, type I and III were included). Patients were stratified based
on Kerr criteria of having unequivocally 16 active and 10 inactive phase cases, with
ages ranging between 14 and 54 years. Six axial slices were scanned (three slices
under the carotid bifurcation and three slices up the arch of aorta). The vessel wall
image appearances were compared between active and inactive phase cases.
Results: All patients had evidence of wall thickening of the primary branches of
the aorta. There were statistically significant differences between active and inactive phase cases in multi-ring thickening of vessel wall (65 and 28), arterial inner
wall enhancement (50 and 19), mixed-signal-intensity outer fat layer (55 and 18),
(P 0.01). And there were statistically significant differences in the thickness of
carotid vascular wall between two groups (P 0.05).
Conclusion: By using the high resolution MR vessel wall imaging at 3.0 T, subtle
mural changes and morphological differences in vessels that existed between the
active and inactive phases were shown. The high resolution imaging of vessel wall
benefited from the application of higher magnetic fields and proved valuable for
more accurate identifying activity of TA.
Scientific Sessions
B-070
11:51
Quantification of arterial wall inflammation in patients with arteriits using
high-resolution DCE-MRI: Correlation with 18 F-FDG PET-CT
C.C. Cyran, T. Saam, S. Soubron, K. Bochmann, M. Hacker, A. Rominger,
T. Pfefferkorn, M.F. Reiser, K. Nikolaou; Munich/DE (clemenscyran@hotmail.com)
B-072
10:39
Novel, fully automated 3D CT lung registration algorithm
O.S. Pianykh1, A.A. Bankier2; 1Newton Highlands, MA/US, 2Boston, MA/US
(opianykh@bidmc.harvard.edu)
Purpose: Robust 3D lung registration is in high demand in experimental and clinical
lung imaging, but its practical implementation is often hampered by human-guided
landmarking. We propose a fully automated 3D lung registration algorithm.
Methods and Materials: We designed a fully automated algorithm that performs
lung registration as a non-rigid transform, using the rib cage as a natural landmark.
First, pixels corresponding to ribs are located with HU thresholding. Second, an
optimal ellipse is fit into the rib cage of each CT section. Third, ellipse centers and
both major and minor axes are polynomially interpolated along the z-direction,
perpendicular to section planes. The resulting nonlinear 3D rib cage model encompasses the entire lung parenchyma, using only a few parameters. Mapping of
these parameters, obtained from two or more CT acquisitions, provides a non-rigid
lung registration transform. We tested the algorithm in: 1) inspiratory and expiratory
CT examinations, 2) dynamic CT acquisitions during expiration, and 3) follow-up
examinations obtained at slightly differing lung volumes. Registration accuracy
was assessed as the percentage of matched rib areas. Registration quality was
assessed using a visual score. Registration time was measured.
Results: The fully automated algorithm was successful in all three test scenarios.
Registration accuracy was 73%, as opposed to 0.5% before registration. The overall
registration quality was excellent. All CT data volumes on a 512 x 512 matrix with
650 sections or less were registered in 10 seconds. No registration required
human interaction.
Conclusion: Our 3D algorithm can perform fully automated non-rigid lung registration with rapid, robust and accurate results.
10:30 - 12:00
B-073
Room K
Computer Applications
SS 205
CAD, image registration and segmentation
Moderators:
N. Karssemeijer; Nijmegen/NL
T. Moritz; Vienna/AT
B-071
10:30
Evaluation of automated versus manual registration techniques for motion
correction of lung tumors in helical breath hold CT images
A. Chandler, T. Pan, W. Wei, D. Herron, E. Anderson, C.S. Ng; Houston, TX/US
(cng@mdanderson.org)
Purpose: To compare the relative performance of manual, rigid, and non-rigid
registration techniques for motion correction of lung tumors in CT images.
Methods and Materials: Twenty-five patient datasets, each consisting of six limited
sequential breath-hold helical volumes through an index lung tumor and one reference
image obtained from a CT perfusion protocol (4x5 mm row MDCT), were evaluated.
Each of the six helical volumes were registered to the reference image using manual
visual and two automated intensity-based registration methods (rigid-translational and
non-rigid free-form deformations (with B-splines)). For each method, 150 registrations
were performed. The performance of each of the three registration techniques for
the tumor regions of interest was assessed by two quantitative alignment metrics
(percentage overlap and distance of center of mass (DCOM)) and by visual validation
(four observers blindly scored the degree of misalignment of each registration on a
5-point scale (ranging from 2 to 50% visual misalignment)).
Results: On both quantitative measures (average overlap and DCOM), rigid (87.7%
and 1.08 mm) and non-rigid (91.8% and 0.41 mm) methods yielded superior
performance compared to the manual method (77.6% and 2.99 mm, respectively)
(p 0.0001). Visual validation confirmed these findings with 10% visual misalignment (considered clinically acceptable) occurring in 99.8 and 100% of registrations
for rigid and non-rigid methods, respectively, compared to 68.5% for the manual
method (p 0.0001). There was no statistical difference in clinically acceptable
performance between the two automated registration methods.
Conclusion: Automated registration techniques achieve significantly better alignment than manual registration, with marginal superiority of non-rigid, compared
to the rigid method.
10:48
Use of a computer aided diagnosis (CAD) system to detect pulmonary
nodules on multidetector-row CT (MDCT) integrated into an existing, multivendor PACS environment: A survey-based assessment
P. Herzog1, S.M. Kirchhoff1, D. O‘Dell2, M. Salganicoff2, M.F. Reiser1, K. Nikolaou1;
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Munich/DE, 2Malvern, PA/US
Purpose: To assess the use of a CAD-system available universally on PACSworkstations versus dedicated workstations.
Methods and Materials: In 2007 a server-based CAD-system was installed, which
automatically detects pulmonary nodules on MDCT-scans, with detection output
going to PACS. A longitudinal survey was administered to the 34 physicians reading
CT-scans of the chest, first prior to the installation and six months after.
Results: Readers read from 5 to 190 scans a week. Prior to server installation, 6
of 34 (18%) used CAD at least once. 11 (32%) were aware that CAD was available institutionally. CAD was applied on an average of 22 cases weekly. Per reader
utilization of CAD averaged 0.2 cases/week, ranging from 0 to 3 cases in 5 of 6
users, with one user applying it on 20 cases per week. The usefulness of CAD was
rated an average of 1.4 on a 5 point scale starting with “1”. After server installation,
30 of the 34 (88%) readers used it at least once and all of them were aware that
it is available. The total number of cases that CAD was (automatically) applied on
averaged 384 per week, the use of CAD results in review rose to an average of 5.9
cases per user/week, the usefulness rating of an average of 3.1.
Conclusion: Data shows that CAD clinical use does not solely depend on hard
criteria such as detection performance but also on soft criteria such as convenience
to use and availability at a PACS routine reading workplace.
B-074
10:57
Artificial neural network applied to MDCT images to differentiate benign vs
malignant nodules: A feasibility study
F. Fraioli, M.L. Mennini, G. Serra, M. Buscema, E. Grossi, C. Catalano,
R. Passariello, L. Bertoletti; Rome/IT (mlmennini@hotmail.it)
Purpose: J-Net belongs to a family of unsupervised artificial adaptive systems
called active connection matrix (ACM). In these systems, each pixel is linked to its
neighbours by weighted connections. Ranges of all possible connections varied in
relation to the alpha parameter. The system automatically emphasizes features that
could be of interest to the human eye such as edges, tissue textures and hidden
shapes from digital images. We applied J-Net to undefined pulmonary nodules
detected by CT scan.
Methods and Materials: A total of 25 pulmonary nodules smaller than 15 mm were
analyzed. Patients were scanned with an MDCT; volumetric nodule images were
transferred on a dedicated software provided by a new artificial neural network.
J-Net considers each image as an active connections matrix, where each node is
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Purpose: To compare 18 F-FDG-PET-CT, which is used clinically to detect inflamed
arteries and to monitor anti-inflammatory treatment in patients with arteriitis, to
high-resolution dynamic contrast-enhanced MRI (DCE-MRI) in its ability to measure
and quantify inflammation in carotid and vertebral arteries. Results of DCE-MRI
were correlated with the gold standard 18 F-FDG-PET-CT.
Methods and Materials: DCE-MRI of the carotid/vertebral arteries of 12 patients
with suspected arteriitis was acquired at 3 T (2D-SR-SGRE) using a dedicated
4-channel surface coil. Patients underwent 18 F-FDG-PET-CT within 1 week of
the MRI scan. The maximum standardized uptake value (SUV) was measured on
PET-CT images at the identical location as the ROIs were set on the MR images.
Dynamic MRI signal intensity data were fitted to a two-compartment kinetic model
to generate values for the following parameters: plasma flow (PF), plasma mean
transit time (PMTT) and extraction flow (EF) across the capillary wall.
Results: Six out of 12 patients were diagnosed with arteriitis. SUV was significantly higher in patients with arteriitis than in patients without arteriitis (1.9 vs.1.2;
p 0.001). SUV correlated positively with EF (r = 0.71; p 0.001) and PMTT (r =
0.6; p 0.001) and correlated negatively with PF (r = -0.49; p 0.002). Patients
with arteriitis as diagnosed by PET-CT had significantly larger EF compared to
patients without arteriitis (p 0.05).
Conclusion: DCE-MRI is applicable to non-invasively measure and quantify arterial
inflammation with good correlation to 18 F-FDG-PET-CT. This method might be
useful in the diagnosis of arteriitis and in monitoring anti-inflammatory therapy.
Scientific Sessions
linked to its nearest neighbors through adaptive weights. Statistical analyses were
performed to evaluate possible differences in shape and morphology after the application of J-NET and to discriminate malignant from benign tumors.
Results: The malignant nodules changed their shape at alpha values lower than
benign ones (A or equal to -0.6); moreover, when the modification between each
alpha cycle was considered, malignant nodules showed a more intense and constant
modification than in benign patients.
Conclusion: J-Net is able to automatically extract features of interest from digital
images. It allows the reduction of image noise while maintaining the spatial resolution
of high contrast structures and the expression of hidden morphological features,
making the halo sign visible and showing differences between malignant versus
benign nodules.
B-075
11:06
Computer-aided detection on digtal chest radiography for pulmonary
nodules screening
Y. Xu, D.-Q. Ma, W. He; Beijing/CN (xuyan0827@yahoo.com.cn)
Purpose: To evaluate the performance of CAD system detecting the pulmonary
nodule on digital chest radiography images.
Methods and Materials: A total of 100 consecutive digital chest radiography examinations were independently evaluated by a radiologist and a CAD pulmonary
nodule detection system (IQQATM-Chest V 1.0,EDDA) designed to identify nodules
ranged from 5 to 15 mm in maximum long-axis diameter. All discrepancies between
the two techniques were reviewed by two expert radiologists (with 15+ experiences
of diagnosis) working in consensus with the reference CT images, and marked
the locations and sizes of the “true” nodule, then stored the results of the marked
nodules as golden standard in the CAD system.
Results: The radiologist detected 95 nodules and the CAD system, 304 nodules. In
total, 134 nodules were classified as true nodules on consensus review. Of the true
nodules present, the radiologist and the CAD detected 82 (61.2%), 105 (78.4%)of
134 nodules, respectively. The radiologist missed 35 true nodules that were only
detected by CAD. The CAD system missed 10 true nodules that were only detected
by radiologist. The radiologist detected 112 (83.6%) nodules using the CAD system.
CAD identified 199 lesions that on consensus review were false-positive nodules,
a rate of 2.0 (199/100) per patient.
Conclusion: CAD detected 78.4% of true nodules and detected 35 nodules in DR
images not identified by radiologists, changing the imaging follow-up protocol of
these subjects. Combining review of DR images by both the radiologist and CAD
was necessary to identify all nodules.
B-076
11:15
Semi-automated lymph node segmentation: Interobserver variability of
metric and volumetric parameters in patients with non-Hodgkin lymphoma
B. Buerke1, M. Puesken1, J. Gerss1, M. Weckesser1, F. Beyer1, M. Suehling2,
W. Heindel1, J. Wessling1; 1Münster/DE, 2Erlangen/DE
Purpose: This study aimed to investigate the feasibility of semi-automated metric
and volumetric analysis of lymph node manifestations in patients with non-Hodgkin
lymphoma compared to manual analysis.
Methods and Materials: Whole body PET-CT at a slice thickness/reconstruction
intervall of 3 mm/2 mm with i.v. contrast was performed in 39 patients. In total,
254 cervical, axillary and inguinal lymph nodes were evaluated retrospectively
and independently by two radiologists and a semi-automated analysis software
regarding RECIST diameter and volume (RECIST size range of 6 to 30 mm).
Statistical analysis was performed using Student t test and intraclass correlation
coefficients.
Results: Automated segmentation without or minor corrections was possible in 228
out of 254 lymph nodes (89.8 %). Mean manual RECIST diameter (13.3 p 4.7 vs.
12.3 p 4.8 mm, r=0.89) and mean semiautomated RECIST diameter (14.8 p 5.2 vs.
13.9p5.3, r=0.83) between both observes were comparable whereas variation was
higher for semi-automated volumetric measurements (1.6 p 2.1 ml vs. 1.7 p 2.5 ml,
r=0.63). Intraobserver variability for manual and semi-automated RECIST (r=0.8)
was low but RECIST diameters obtained semi-automatically were significantly
oversized as compared to the manual assessments (p 0.001).
Conclusion: Semi-automated RECIST, WHO and volume measurements in lymph
nodes are feasible in terms of intra- and interobserver variability. A systematic and
significant trend towards size overestimations requires accurate correction of the
automated segmentation results.
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B-077
11:24
Approach to multi-sequence image analysis in diagnosis of multiple
sclerosis
J. Kawa1, E. Pietka1, A. Kieltyka2; 1Gliwice/PL, 2Katowice/PL (jkawa@polsl.pl)
Purpose: Diagnosis and follow-up procedure of Multiple Sclerosis (MS) requires
demyelination plaques to be detected and measured. In this study, the multisequence analysis of FLAIR and T2-WI images has been developed and tested in
order to automatically segment the lesions.
Methods and Materials: Axial T2-WI and FLAIR Magnetic Resonance images have
been acquired from 40 patients with MS. The methodology has been designed in
order to automatically segment the plaques using fuzzy clustering algorithms in
kernel space, connectivity analysis and statistical models. Knowledge based corrections have been applied to increase performance of the method. During evaluation,
a test subset of randomly selected cases have been created. The 20 test cases
have been radiologically examined and the plaques have been outlined.
Results: The performance has been verified by interobserver comparison with the
gold standard. The evaluation was based on Dice Similarity Coefficient (79%, std.
8% with intraobserver 83%), sensitivity (89%, std. 8.5%, cf. intraobserver 90%)
and specificity measure (99.95%, std. 0.04%, cf. intraobserver 99.99%). Visual
comparison revealed reduced accuracy for lacunar lesions and plaques located
within the grey matter.
Conclusion: An automatic methodology can be used for segmentation of MS
lesions. The obtained accuracy permits for fast analysis and estimation of volume
of the demyelinated tissue.
B-078
11:33
Performance of a prototype computer aided diagnosis (CAD) tool for the
detection of lymph nodes at multidetector-row CT
P. Herzog, M.F. Reiser, G.T. Schmidt, R. Korn, G. Binnig, K. Nikolaou; Munich/DE
Purpose: To assess the performance of a CAD tool for the detection of lymph
nodes.
Methods and Materials: 18 MDCT datasets of the chest or abdomen were randomly selected. Axial images of 5 mm slice width were independently analysed by
two readers, asked to report every LN greater than 5 mm in maximum diameter.
Furthermore, all studies were additionally submitted to a CAD tool. A consensus
panel (CP) of two experienced radiologists validated the LN found by both, the
readers and the CAD tool, and also detected additional lesions.
Results: CP confirmed 589 lesions with diameters ranging from 5 - 64 mm. 301
(51%) LN were correctly found by the readers, while 288 were missed (49%). 102
lesions were solely marked by reader 1, while 165 were detected only by reader
2. 34 lesions were detected by both readers. Inter rater agreement revealed a
Cohen’s-Kappa-value of 0.089. CAD detected 851 candidate lesions; 442 were
confirmed by CP (52%) while 409 were dismissed as false positives (48%). 260
nodes were marked by both, CAD and the readers together (42%); 241 lesions
(41%) were found uniquely by CAD and 41 nodes (7.0%) were found solely by the
readers. 47 LN (8.0%) were found only by the consensus panel. Working alone,
reader 1 had a sensitivity of 23%, reader 2 of 34%, whereas an individual reader
plus CAD would have had an sensitivity of 84 and 91%, respectively.
Conclusion: CAD has the potential to significantly increase the number of detected
lymph nodes.
B-079
11:42
Automated segmentation of volumes on MR imaging: Validation, accuracy
and relationship of error to imaging parameters
S. Ghosh-Ray, S. Rosa, A.P. Toms, A. Clark; Norwich/UK
(subhadip.ghosh-ray@nnuh.nhs.uk)
Purpose: Automated volume segmentation is available on a number of platforms,
including open source software, and is useful for monitoring tumour size during
treatment. However, the accuracy of these tools depends on imaging parameters
such as slice thickness therefore the purpose of this study is to determine the
relationship between volume, slice thickness and standard error of measurement
(SEM) during volume segmentation on MRI.
Methods and Materials: A phantom was constructed using acrylic spheres
(12.7-76.2 mm diameter) machined to high tolerances. High resolution T2W MR
images were acquired at 0.9, 2, 4, 6 and 8 mm slice with either no inter-slice or a
20% inter-slice gap. Two observers independently measured the volumes of the
spheres using an automated propagating segmentation tool (Osirix®), which were
then compared with the known volumes.
Results: The accuracy of the segmented volumes decreased proportionally with
the volume of the spheres (SEM range: 1.76 to 14.11%). As slice thickness and
Scientific Sessions
B-080
11:51
CAD-based analysis of vascularization pattern of axillary lymph nodes in
breast MRI and ist diagnostic potential
A. Malich, A. Kott, D. Hentrich; Nordhausen/DE (ansgar.malich@shk-ndh.de)
Purpose: MR-based analysis of lymph nodes is still a diagnostic challenge. The
study is aimed to analyze dynamic pattern of metastatic and non metastatic nodes
in comparison to those of the malignant tumor using different CAD-systems.
Methods and Materials: Confirma (USA, CAD1) and CADSciences (USA, CAD2)
were used. 100 breast-MRI containing a malignant lesion were analyzed using
both modalities including axillary edge and nodes (histologically proven). 0.1 mmol
Gd-DTPA Gadolinium/kgbw were applied. All available data including permeability,
extracellular volume fraction, peak uptake, worst wash in, worst wash out, dynamic
enhancement of the entire lesion/node were matched.
Results: Using both CAD-systems, peak contrast uptake differed highly significant
between metastatic and non metastatic node suggesting being stronger and faster
at metastatic nodes (CAD1: 423%/191%; CAD2: 1641%/751%). Wash out occurs
in benign and malignant nodes similarly. There was no significant correlation of
dynamic distribution of the primer malignant lesion and the metastatic node neither
regarding the extent of uptake nor regarding the percentage distribution of enhancement pattern of malignancy and related metastasis. Both CAD-systems differed
significantly regarding volume calculation and percentage distribution of contrast
uptake. Using cut off of 240% initial uptake (CAD1) allows an accurate discrimination
of malignant and benign nodes (sensitivitiy 89%, specificity 85%).
Conclusion: Maximum (peak) contrast uptake and rapid initial uptake differ significantly dignitiy-dependent amongst the several nodes not influenced by alternative
CAD-technologies. Total value of contrast uptake of both CAD-systems differ due to
significantly different volume calculations, relative differences benign vs. malignant
nodes are similar, however.
10:30 - 12:00
Room L/M
Neuro
SS 211
Diffusion tensor imaging
Moderators:
Q.-Y. Gong; Chengdu/CN
W. Van Hecke; Antwerp/BE
B-081
10:30
Combined MR spectroscopy and diffusion tensor imaging to evaluate the
therapy of transplanting olfactory ensheathing cells for amyotrophic lateral
sclerosis
Y. Xue, R. Zhai, K. Tan; Beijing/CN (xyp7425@sina.com)
Purpose: To evaluate the safety and effectiveness of transplanting olfactory
ensheathing cells to treat amyotrophic lateral sclerosis (ALS) using 1H-MRS in
conjunction with DTI.
Methods and Materials: 15 ALS patients and 12 healthy control subjects were
studied with 1H-MRS and DTI on GE Sigma 3.0 T MR system. The NAA/Cr ratios
and FA were measured in the brain before and after receiving olfactory ensheathing
cells (OECs) transplantation (2 weeks and 6 months) in ALS.
Results: 1) Before treatment, compared with that of control groups, the FA values
of ALS reduced significantly in the all detected sites in the brain, and the NAA/Cr
ratios decreased in the subcortical white matter and corona radiata. 2) 2 weeks
after treatment, the FA values remained unchanged, and the NAA/Cr increased
obviously in the posterior limb of the internal capsule and subcortical white matter.
3) 6 months after treatment, the FA values increased significantly in the corona
radiata and the corpus callosum. While the ratios of NAA/Cr decreased significantly
in the subcortical white matter.
Conclusion: Both DTI and 1H-MRS can be served as potential means to evaluate
therapeutic effectiveness. The improved NAA/Cr ratios (2 weeks) and FA values (6
months) in some locations in the brain supported the point that OECs transplantation might be benefit for ALS, but the difference of the results from 1H-MRS and
DTI need further investigation.
B-083
10:39
Whole brain diffusion tensor imaging in Parkinson’s disease: Changes in
the olfactory tract and the cerebellum
K. Zhang, K. Li, C. Yu; Beijing/CN (kaiyuanzhang@yahoo.cn)
Purpose: The white matter of the brain is involved in the pathologic processes
of Parkinson’s disease (PD). Previous diffusion studies on PD have focused on
the differential diagnosis and found the differences in diffusion indexes between
patients with PD and patients with atypical parkinsonian disorder (APD). But few
diffusion studies have focused on the damage of the white matter integrity itself
in patients with PD using voxel-based analysis. The purpose of our study is to
investigate the abnormal diffusion in the brain white matter of patients with PD in
a whole brain manner.
Methods and Materials: Diffusion tensor imaging (DTI) of the brain was obtained
in 26 patients with PD and 26 age- and sex-matched normal subjects. The differences in the fractional anisotropy (FA) and mean diffusivity (MD) between groups
were studied with the voxel-based analysis (VBA) of the whole brain DTI data.
The correlations between the abnormal diffusion and the clinical data including
the olfactory function were also evaluated in the PD patients.
Results: Decreased FA was found in the bilateral cerebella and decreased FA
and increased MD were found in the olfactory tract area. Moreover, there was a
significant correlation between the FA in the cluster of the right medial cerebellum
white matter and the threshold of olfactory identification.
Conclusion: Our research suggests that the damage of white matter in the cerebellar and olfactory tract area might be the underlying mechanism for olfactory
dysfunction in PD.
B-084
10:48
Human lymphotropic virus type I associated myelopathy/tropical spastic
paraparesis: A study of the white matter with diffusion tensor MR imaging
E.L. Gasparetto, L.H. da Cruz Jr, T. Doring, R. Borges, R.C. Domingues,
R.C. Domingues; Rio de Janeiro/BR (egasparetto@gmail.com)
Purpose: To evaluate the diffusion tensor imaging (DTI) abnormalities in the white
matter of patients with human lymphotropic virus type I associated myelopathy/
tropical spastic paraparesis (HAM/TSP).
Methods and Materials: A total of 11 patients with HAM/TSP and a control group
underwent brain MRI at 1.5 T scanner with conventional protocol and DTI. The DTI
data were post-processed and fractional anisotropy (FA) maps were calculated.
The FA values were measured with a ROI-based technique in the white matter
lesions (WML), normal-appearing white matter (NAWM) around them, as well as
NAWM more than 1 cm distant from the lesions and contralateral. In addition, using
a voxel-based technique, the mean FA of the whole brain, grey matter and white
matter was compared between the two groups.
Results: The FA was significantly reduced in the WML (mean FA = 0.285) and
in the NAWM around them (mean FA = 0.386) compared with controls (mean
FA = 0.662) (p 0.001). However, there was no significant reduction in FA of the
NAWM distant from the lesions (mean FA = 0.602) and contralateral to the lesions
(mean FA = 0.587) (p 0.05). Finally, no significant differences were observed in
the mean FA of the whole brain, grey matter and white matter between the two
groups (p 0.05).
Conclusion: In this group of HAM/TSP, we observed reduced FA values in the WML
and NAWM around them, but no significant abnormalities in the NAWM distant from
the lesions. Different from other demyelinating diseases, the infectious or inflammatory process in patients with HAM/TSP seems to be restricted to the WML and
the NAWM around them, preserving the remaining NAWM.
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effective slice thickness increase so the error for a known volume increases. The
MR acquisitions with inter-slice gaps produced volumes that were closest to the
known volume of the spheres. The SEM for a known lesion diameter (d) and slice
thickness (t) can be predicted from the following formulae: With a 20% inter-slice
gap: SEM = 29.02e-0.06d/t. With no inter-slice gap: SEM = 32.11e-0.04d/t.
Conclusion: Automated volume segmentation is an accurate tool for measuring
volumes of spheres within a phantom. The formulae presented above can be used
to plan MR examinations for a given SEM.
Scientific Sessions
B-085
10:57
Changes of DTI in tMCAO rats with acupuncture therapy
F. Miao, Z.-Y. Wu, Q.-Y. Xiang; Shanghai/CN (mf11066@rjh.com.cn)
Purpose: To assess the effects of acupuncture therapy in tMCAO rats and discuss
its mechanisms.
Methods and Materials: SD rats were divided into three groups. Group 1 underwent
tMCAO and received acupuncture therapy, group 2 also underwent tMCAO but
had no therapy, and group 3 underwent sham operation. The evolutions of diffusion tensor imaging (DTI) features of ischemic lesions at acute to chronic periods
were assessed and the correlations with behavioral tests, DTI appearances, and
histopathological changes were discussed.
Results: Behavioral scores of group 1 reduced gradually with acupuncture therapy
and no significant change was seen in group 2. rADC and rFA values in the center
and the edge of ischemic lesions reduced at first and then elevated in varying
degrees. In the two tMCAO groups, only the changes in rFA value at the edge of
ischemic lesions had significant difference. More significant increase of GAP-43
and synaptophysin protein expression was found in group 1 than in group 2 and
group 3. No significant correlations were found between behavioral test results, DTI
appearances, and immunohistochemical results when data was grouped.
Conclusion: The acupoints applied in this study were effective for the functional
recovery, and improving neuronal regeneration might play a certain role in mechanism of acupuncture therapy to poststroke paralysis of the limbs in these rats.
MRI, in particular FA value of DTI, was an appropriate parameter to evaluate the
recovery status.
B-087
11:06
Quantitative brain MRS and DTI on the impact of fluoxetine in MS
P.E. Sijens, J.P. Mostert, R. Irwan, J. Potze, J. De Keyser, M. Oudkerk;
Groningen/NL (p.e.sijens@rad.umcg.nl)
Purpose: The antidepressant fluoxetine stimulates astrocytic glycogenolysis, which
serves as an energy source for axons. In multiple sclerosis patients, fluoxetine administration may improve the energy supply to neuron cells and thus inhibit axonal
degeneration. We studied this phenomenon by diffusion tensor imaging (DTI) and
1H magnetic resonance spectroscopy (MRS).
Methods and Materials: In a pilot study, 15 multiple sclerosis (MS) patients
were examined by quantitative DTI (b = 0 and 1,000 s/mm2) and 1H MRS (TR/TE
1,500/135 ms) in order to quantify the brain tissue diffusion properties (fractional
anisotropy, apparent diffusion coefficient) and metabolite levels (choline, creatine
and N-acetylaspartate) in the cortical gray matter brain tissue, in normal appearing
white matter and in white matter lesions.
Results: After oral administration of fluoxetine (20 mg/day) for 1 week, the DTI
and MRS measurements were repeated and after treatment with a higher dose
(40 mg/day) during the next week, a third series of DTI/MRS examinations was
performed in order to assess any changes in diffusion properties and metabolism.
One trend was observed in the gray matter tissue, a decrease of choline measured
at weeks 1 and 2 (significant in a subgroup of 11 relapsing remitting/secondary
progressive MS patients). In the white matter lesions, the apparent diffusion coefficient was increased at week 1 and N-acetylaspartate was increased at week 2
(both significant).
Conclusion: These results provide evidence of a neuroprotective effect of fluoxetine
in multiple sclerosis by the observed partial normalization of the structure-related
MRS parameter N-acetyl aspartate in white matter lesions.
B-088
11:15
Diffusion tensor imaging of high-grade gliomas and brain metastases
W.H. Flatz1, O. Dietrich1, S.O. Schönberg2, B.B. Ertl-Wagner1, M.F. Reiser1;
1
Munich/DE, 2Mannheim/DE (radiologie.muenchen@gmail.com)
Purpose: The objective of our study was to detect and evaluate intra- and peritumoral mean diffusivity and fractional anisotropy to differentiate between high-grade
gliomas and brain metastases.
Methods and Materials: Eighteen previously untreated patients suffering from
histologically proven high-grade glioma and 14 patients diagnosed with brain
metastases from breast cancer were examined in our study. MRI was performed
using a 3 T scanner acquiring DTI images with 12 directions. The regions of interest
(ROI) for DTI evaluation were positioned into different parts of the tumor, normal
appearing white matter and the vasogenic edema adjacent to tumor depicted as
abnormal areas in T2-weighted images.
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Results: Significant decrease of fractional anisotropy (FA) (p 0.005) and significant
increase of mean diffusivity (MD) (p 0.005) were found in the peritumoral regions
compared to normal appearing white matter. For brain metastases the peritumoral
MD was significantely increased compared to high-grade gliomas (p 0.005).
Peritumoral FA showed no significant differences among the two patient groups.
Intratumoral FA was increased in high-grade gliomas and in metastatic disease.
Conclusion: Due to increased extracellular water content, diffusion parameters
show a pathological change within the peritumoral vasogenic edema in both
high-grade gliomas and metastases. Unlike FA, MD can be used to differentiate
between high-grade gliomas and metastatic tumors, pointing towards probable
tumor infiltration characterized by MD values.
B-089
11:24
Combined study of fMRI and DTI for working memory of children with
learning disability
C. Pan; Wuhan/CN (panchu@21cn.com)
Purpose: To examine brain activity of working memory and anisotropy of the
fronto-parietal white matter in children with learning disability (LD) by combining
fMRI and DTI.
Methods and Materials: Twelve children with LD aged 10-12 years and twelve
children matched in age and sex as normal control were investigated. Brain activity
of working memory was measured using BOLD-fMRI during performance of paced
visual serial addition test. The data group studies were analyzed using SPM2. White
matter was investigated using diffusion tensor imaging (DTI). The activity map were
overlaid upon FA maps. The correlation between BOLD response and FA values
of the ROIs in fronto-parietal lobe were statistically analyzed.
Results: 1. In bilaterally inferior parietal lobe, inferior frontal gyrus, and left superior frontal gyrus, left medial frontal gyrus and left cingulate gyrus, children with
LD showed weaker activation than matched children. In left superior parietal lobe
and right inferior frontal gyrus, children with LD showed no activation. 2. The white
matter FA values in left fronto-parietal (P=0.027), left parietal lobe (P=0.031) and
left frontal lobe (P=0.018) in children with LD were lower than matched children. 3.
Both in two group children, the mean of BOLD activated voxels in the dorsolateral
prefrontal cortex (DLPFC) has the positive correlation with FA values in frontoparietal white matter.
Conclusion: The weaker BOLD response and lower FA values of children with
LD in fronto-parietal lobe suggests the poorer maturation of grey and white matter,
which maybe is the pathogenesis of learning disorders.
B-090
11:33
Diffusion tensor imaging in patients with idiopathic normal pressure
hydrocephalus: A pilot study
E. Hattingen, A. Jurcoane, O. Singer, O. Singer; Frankfurt/DE
(elke.hattingen@kgu.de)
Purpose: Diffusion tensor imaging (DTI) parameters were investigated in patients
with idiopathic normal-pressure hydrocephalus (iNPH) to evaluate micro-structural
damage of brain tissue due to chronic ventricular dilatation.
Methods and Materials: 11 patients with iNPH and 10 healthy controls underwent
MRI at 3 Tesla including DTI examination with 12 gradient directions. iNPH patients
were scanned before and after lumbar CSF withdrawal tests. Tract-based spatial
statistics and manually defined regions of interest approaches were performed to
analyze differences in fractional anisotropy (FA) and mean diffusivity (MD) between
patients and controls. In iNPH patients, changes in FA and MD before and after
lumbar CSF drainage were analyzed.
Results: Compared to the control group, iNPH patients had significantly higher MD
values in both the periventricular corticospinal tract (CST) and the corpus callosum
(CC) while FA values were significantly higher in CST but lower in the CC. In iNPH
patients, MD decreased significantly in the CC after lumbar CSF drainage.
Conclusion: Significant changes of MD and FA in iNPH patients imply mechanical
and microstructural changes in periventricular functional relevant brain structures.
These changes are at least partially reversible. Further investigations of DTI parameters in iNPH, possibly also observing the effect of CSF shunting, may add to
a better understanding of the pathophysiological mechanisms leading to iNPH.
Scientific Sessions
10:30 - 12:00
Room N/O
Abdominal Viscera (Solid Organs)
Liver: Hepatocellular carcinoma
Moderators:
I. Bargellini; Pisa/IT
D.J. Lomas; Cambridge/UK
B-091
10:30
Value of double-contrast liver MRI at 3.0 T in differentiating welldifferentiated hepatocellular carcinomas from dysplastic nodules:
Multivariate analysis
M. Yoon, S. Kim, J. Lee, J. Lee, J. Han, B. Choi; Seoul/KR (mina11360@gmail.com)
Purpose: To determine significant MRI findings for differentiation of well-differentiated hepatocellular carcinomas from dysplastic nodules on double-contrast MRI.
Methods and Materials: A total of 28 transplantation recipients with 32 W/D
HCCs and 33 DNs underwent DC-MRI using SPIO and Gadolinium agents on a
3 T unit. Precontrast (NCE) T1W GRE and T2W FSE images and SPIO-enhanced
T2W FSE and T2*W GRE images were obtained. After Gd administration, arterial
(AP), portal (PP) and equilibrium images were scanned. Two reviewers analyzed
the signal intensities on each sequence. On AP images, the degree of enhancements was categorized into four groups: no, minimal, moderate and strong. For
quantitative analysis, the relative arterial enhancement ratio (RAE) was calculated.
Each variable was evaluated with univariate tests and then with multivariate logistic
regression analysis to find the most predictable finding.
Results: Of the 32 W/D HCCs, 20 showed iso or high SI on NCE T2W images,
while 20 of 33 DNs showed low SI. On post-SPIO and pre-Gd T1W GRE images,
28 W/D HCCs showed iso or high SI while 24 DNs showed low SI. On post-Gd AP
images, 22 W/D HCCs revealed at least minimal enhancement, whereas 31 DNs
did not show any. RAE of W/D HCCs (40.4%) was also significantly larger than
that of DNs (16.2%). Multivariate analysis revealed subjective degree of enhancement on AP images and was the only variable that independently differentiated
W/D HCCs from DNs.
Conclusion: Subjective degree of enhancement on post-SPIO and Gd AP images is the only independent variable that distinguishes W/D HCCs from DNs
on DC-MRI.
B-092
10:39
Can MR imaging predict microvascular invasion in patients with
hepatocellular carcinoma?
J. Lonjon Blanc, V. Schembri, B. Gallix, J.-M. Bruel; Montpellier/FR
(j-lonjon@chu-montpellier.fr)
Purpose: The aim of this study was to determine MR features predictive of microvascular invasion in patients with HCC nodules before hepatic resection.
Methods and Materials: 54 patients who underwent curative resection for HCC
(n=30) or liver transplantation (n=24) were included in this retrospective study. Dynamic MR imaging was performed within 6 months before surgery (mean 82 days,
SD 75 days) were evaluated regarding nodule size and number, T2 hyper-intensity,
capsule visualization and integrity, presence of an hyper-vascularisation, wash-out,
portal shunt and thrombosis. Results were correlated with pathological analysis.
Results: Irregularity of the peripheral part of the nodule or disrupted capsule by MR
was correlated with microvascular invasion (p 0.05). Nodule size superior to 3 cm
significantly correlated with microvascular invasion (p 0.001). Number of nodules,
T2 signal intensity, vascular enhancement, arterio-portal shunt and presence of a
wash-out were not significantly correlated with vascular invasion.
Conclusion: HCC nodule size measuring more than 3 cm and irregularity of the
peripheral surface or capsule of the nodule as determined by MR imaging are
predictive of microvascular invasion.
B-093
10:48
Loss of typical wash-out pattern of hepatocellular carcinomas on doublecontrast liver MRI: Overcoming with quantitative analysis of enhancement
patterns
J.-H. Yoon, J. Lee; Seoul/KR (jhjhry@gmail.com)
Purpose: To investigate if quantitative analysis can overcome a major drawback
of double-contrast liver MRI that conceals typical wash-out enhancement pattern
of hepatocellular carcinomas.
B-094
10:57
Intraindividual comparison of hepatic venous phase and delayed phase for
the detection of washout contrast-enhancement pattern of HCC on MDCT
of the liver
A. Furlan1, G. Brancatelli2, D. Marin3, G. Palermo Patera2, A. Ronzoni4, M. Midiri2,
M. Bazzocchi1, A. Vanzulli4; 1Udine/IT, 2Palermo/IT, 3Rome/IT, 4Milan/IT
(ali.furlan@gmail.com)
Purpose: To retrospectively compare the hepatic venous phase (HVP) with the
delayed phase (DP) for the detection of washout contrast-enhancement pattern of
HCC lesions on MDCT of the liver.
Methods and Materials: The study cohort comprised 30 cirrhotic patients (25
men, 5 women; mean age, 57 years; range, 33-66) who underwent multiphasic
64-slice MDCT of the liver during 90 days before liver transplantation. CT was
performed immediately before i.v. contrast medium administration (2 mL/Kg body
weight of iomeprol, 350 mgI/mL at 3.5-4.0 mL/s) and during the hepatic arterial
dominant phase, HVP and DP, obtained respectively at 12, 55 and 120 s after the
trigger threshold (120 HU at the level of the abdominal aorta) using automatic
bolus tracking. Two radiologists qualitatively evaluated the CT images during the
HVP and DP for the detection of tumor washout contrast-enhancement pattern.
Additionally, tumor-to-liver contrast-to-noise ratio (CNR) was measured for each
lesion at both phases.
Results: At pathologic examination of explanted livers, 61 HCCs (mean size,
1.6 cm; range, 0.8-4.2 cm) were confirmed in 27 patients. Of the 61 HCCs, 47 (77%)
were detected on MDCT. A significantly higher number of tumors demonstrated a
washout contrast-enhancement pattern during the DP (19 of 47, 40%) compared to
the HVP (12 of 47, 26%) (P 0.0001, McNemar’s test). Lesion-to-liver mean CNR
increased significantly during the DP (-2.07p1.2) compared to the HVP (-1.33p1.4)
(P = 0.0003, Student’s t-test).
Conclusion: DP is superior to HVP in the detection of washout contrast-enhancement pattern of HCC at multiphasic 64-section MDCT of the liver.
B-095
11:06
Histologic grading of hepatocellular nodule in cirrhotic liver disease:
Analysis of characterization performance of DW MRI, Gd-EOB-DTPAenhanced MRI and a combined protocol
S. Zaid, L. Crespi, T. Ierace, P. Marelli, L. Solbiati; Busto Arsizio/IT
(soraya.zaid@libero.it)
Purpose: To assess the characterization accuracy of histologically graded liver nodules in cirrhotic liver using diffusion-weighted (DW) MR, Gd-EOB-DTPA-enhanced
MRI and a combination protocol.
Methods and Materials: A total of 28 cirrhotic patients with 33 pathology-defined
liver lesions underwent MRI scans, evaluated independently and prospectively by
three blinded radiologists with equivalent experience. DW protocol included routine
axial T1W, T2W and DW sequences; Hepatocyte-specific protocol consisted of T1W,
T2W and Gd-EOB-DTPA triphasic and late hepatocyte-specific phase; combined
protocol included both DWI and Gd-EOB-DTPA MRI protocol. Histologically, liver
lesions were classified as dysplastic nodules (DN), well-differentiated (WD) HCC
and moderately or poorly differentiated (M-PD) HCC. Each lesion was classified
according to its ADC value on DW sequences with three increasing b-values (50,
400 and 800 sec/mm²) and its enhancement features at Gd-EOB-DTPA arterial,
portal and late (at 20 min) phases, with categorized signal intensity at late phase
(no hepato-specific absorption, low, subtle, iso).
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SS 201b
Methods and Materials: Forty-four histologically proven HCCs in 41 patients were
included in the study with a control group of 100 hemangiomas of 73 patients. All
patients underwent double contrast liver MR [superparamagnetic iron oxide (SPIO)
and then gadolinium (Gd) enhancement]. Qualitative analysis with visual inspection
was performed regarding the presence of arterial enhancement and washout of
HCCs. Regions-of-interest of each lesion and its adjacent liver parenchyma were
measured on T1W dynamic sequences after Gd enhancement. Lesion-to-liver ratio
on all sequences and the difference of lesion-to-liver ratio among each dynamic
phase were calculated. Data from all lesions were analyzed using the Student t-test
and receiver operating curve (ROC) analysis.
Results: Lesion-to-liver ratio on dynamic T1W images over time revealed decrease
in 91% of HCCs whereas visual inspection revealed washout pattern in only 23%
of HCCs. As a control group, 86% of hemangiomas showed increase of lesion-toliver ration during dynamic phases. The most significant parameter between HCCs
and hemangiomas was lesion-to-liver ratio difference between arterial phase and
3 minute-delayed sequences (p=0.001, Az=0.94).
Conclusion: Quantitative analysis of tumoral enhancement on dynamic phases
may overcome the major pitfall of double-contrast liver MRI.
Scientific Sessions
Results: DW protocol allowed correct characterization of 28 (84.8%) liver nodules,
with a superiority in identifying foci of M-PD HCC within WD HCC. Liver-specific
contrast agent protocol characterized 26 (78.7%) liver nodules, displaying higher
accuracy in distinguishing between DN and WD-HCC. The combined assessment
improved the characterization performance by up to 96.9 %.
Conclusion: Liver nodules characterization in chronic liver disease significantly benefits from the association of DW sequences and liver-specific Gd-EOB-DTPA.
B-096
11:15
Intraindividual comparison of gadoxetic acid (Gd-EOB-DTPA) enhanced
MR imaging and multiphasic 64-slice CT for the detection of hepatocellular
carcinoma (HCC) in patients with cirrhosis
M. Di Martino, D. Marin, A. Guerrisi, D. Geiger, C. Catalano, R. Passariello;
Rome/IT (dimase81_6@hotmail.com)
Purpose: To intraindividually compare Gadoxetic acid (Gd-EOB-DTPA) enhanced
MRI and 64-slice CT for the detection of HCC in patients with cirrhosis.
Methods and Materials: Informed consent and ethical approval were obtained.
Thirty-seven consecutive patients with 67 HCC nodules underwent MRI at 1.5 T
(Avanto, Siemens) and 64-slice CT (Sensation 64, Siemens) at a mean interval of
14 days (range 10-20 days). MR acquisitions comprised unenhanced breath-hold
T2W images and volumetric 3D Gd-EOB-DTPA-enhanced (0.1 mmol/kg; Primovist®)
T1W GRE images acquired at 25, 60, 180 s (dynamic phase) and 20 min (hepatobiliary phase). 64-slice CT was performed with 0.6 x 64 mm collimation, 3-mm
section thickness, 250 mAs, 120 kVp. A triple-phase protocol was started 18, 60
and 180s after reaching a trigger threshold of 150 HU above baseline CT number
of the aorta. Image analysis was independently performed by three observers in
two sessions separated by 4 weeks. Diagnostic accuracy was evaluated using
the alternative-free response receiver operating characteristic (AFROC) method.
Sensitivity, specificity and positive predictive value (PPV) with corresponding 95%
confidence intervals were determined.
Results: On a lesion-by-lesion basis, the mean area under the AFROC curve for
Gd-EOB-DTPA MRI (0.88) was significantly higher than that of CT (0.77) (P 0.05),
the mean sensitivity (81.1%) and specificity (94.7%) of Gd-EOB-DTPA MRI was
significantly higher than that of CT (65.5%,) and (84.2%) (P 0.05). No statistical
significant difference was obtained in terms of PPV.
Conclusion: Gd-EOB-DTPA-enhanced MRI is significantly more accurate, sensitive
and specific than 64-slice CT for the diagnosis of HCC in patients with cirrhosis.
B-097
11:24
A two-centre study for the comparison of GD-EOB-DTPA (PRIMOVIST)enhanced MRI versus triple-phase MDCT for the detection of
hepatocellular carcinoma in cirrhosis
A. Luca1, L. Grazioli2, S. Caruso1, R. Tinti2, M. Milazzo1, M. Bondioni2;
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Palermo/IT, 2Brescia/IT (aluca@ismett.edu)
Purpose: To compare the diagnostic performance of MRI using gadoxetic acid
(Gd-EOB-DTPA, Primovist, Bayer-Schering Pharma, Berlin, Germany) with triplephase multidetector CT for the detection of HCC in cirrhotic patients.
Methods and Materials: 110 cirrhotic patients with HCC underwent MRI and
MDCT. Images were acquired before and after contrast agent administration in
arterial, portal venous and equilibrium phases. Hepatobiliary phase images were
obtained 5, 15 and 20 minutes after Gd-EOB-DTPA. The diagnostic accuracy for
HCC was evaluated with nodule-by-nodule and patient-by-patient analyses. Sensitivity analyses were performed according to overall HCC, main HCC and secondary
(satellite or metastatic) HCC.
Results: On a per nodule basis, overall sensitivity of Gd-EOB-DTPA-MRI for the diagnosis of HCC was significantly superior to triple-phase MDCT (178/185 [96%] vs.
156/185 [84%], P = 0.009). Gd-EOB-DTPA-MRI and MDCT detected 106/110 [96%]
and 107/110 [97%] main HCC, respectively (NS). Sensitivity of Gd-EOB-DTPA-MRI
for detection of secondary HCC was significantly superior to MDCT (72/75 [95%] vs.
49/75 [65%], respectively, P 0.005). On a per patient basis, in 86 (78%) patients
there was a concordance between MRI and MDCT, in 20 (18%) patients MRI alone
detected 29 HCC and in 4 (4%) patients MDCT alone detected 7 HCC; the mean
diameter of lesions detected with a single imaging modality was 19.3 mm and the
size class was 10 mm (n=3), 10-20 mm (n=24) and 20 mm (n=9).
Conclusion: In patients with cirrhosis, Gd-EOB-DTPA-enhanced MRI is more accurate than triple-phase MDCT for detection and characterization of small satellite
or metastatic HCC.
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B-098
11:33
Evaluation of additional value of SPIO-enhanced MR imaging for
noninvasive imaging diagnosis of hepatocellular carcinoma in cirrhotic
liver: Validation of EASL diagnostic criteria
H. Yoo, J. Lee, J. Lee, S. Kim, S. Kim, J. Han, B. Choi; Seoul/KR
(jmsh@snu.ac.kr)
Purpose: To validate the EASL diagnostic criteria for Hepatocellular Carcinoma
(HCC) in cirrhotic liver and to determine the additional value of superparamagnetic
iron oxide (SPIO)-enhanced MRI in the diagnosis of HCC.
Methods and Materials: This study included 108 patients with 153 histologically
confirmed hepatocellular nodules, i.e. 26 dysplastic nodules (DNs), and 127 HCCs,
who underwent dynamic-CT and double-contrast-enhanced (DCE) MRI with SPIO
and gadobenate-dimeglumine. Two reviewers analyzed the hypervascularity of
the nodules on dynamic CT and MR images, and their signal intensity on SPIOenhanced images using consensus. First, the reviewers were requested to make a
diagnosis of HCC according to EASL recommendation. Second, among the nodules
that did not meet the EASL-criteria using CT and dynamic-MRI, nodules with a low
uptake of SPIO on MRI were also considered as HCCs. Sensitivity, specificity were
assessed based on EASL diagnostic criteria for HCC using both CT and dynamicMRI and then, reassessed in combination with SPIO-enhanced MRI.
Results: Of 127 HCCs, 79 HCCs were larger than 2 cm in diameter, 37 HCCs were
between 1 and 2 cm, and 11 HCCs were smaller than 1 cm. A significant improvement
in the sensitivity (78-95%) was achieved by adding SPIO-enhanced MR images to
EASL-criteria (p 0.01). When EASL-criteria were applied for the HCCs between 1
and 2 cm, of 37 HCCs, diagnosis was correct for 21 lesions (57%) with EASL criteria,
and 30 lesions (81%) with combined SPIO-enhanced MR images.
Conclusion: Adding SPIO-enhanced images to the two dynamic imaging modalities, provides improvements in the non-invasive diagnosis of HCCs compared with
only EASL criteria, especially in making a diagnosis of non-hypervascular HCCs.
B-099
11:42
Prospective validation of AASLD guidelines for the early diagnosis of
hepatocellular carcinoma in cirrhotic patients
L.V. Forzenigo, A. Sangiovanni, M.A. Manini, M. Iavarone, M. Fraquelli,
R. Romeo, P. Biondetti, M. Colombo; Milan/IT (laura.v.f@libero.it)
Purpose: Confident diagnosis of HCC in cirrhotics under US surveillance is currently
based on invasive and non-invasive imaging criteria. We evaluated the sensitivity,
specificity and positive and negative predictive values (PPV, NPV) of contrast-enhanced
ultrasound (CE-US), CT and MRI in patients with de-novo liver nodes (LN).
Methods and Materials: A total of 46 Child-Pugh A cirrhotics, mean age 65 yr,
with 33 (72%) males, under US surveillance at 6-month intervals, who developed
an LN, underwent CE-US, TC, MRI and fine-needle biopsy (FNB). FNB was the
diagnostic gold standard.
Results: A total of 48 LN were identified: 1 (2%) 1 cm, 42 (88%) 1-2 cm, 5
(10%) 2 cm; 28 (58%) HCC: 1 (4%) 1 cm, 23 (82%) 1-2 cm, 4 (14%) 2 cm; 1
(2%) cholangiocarcinoma; 17 (36%) macroregenerative nodes; 2 (4%) low-grade
dysplastic nodes. Among the 1-2 cm LN, a typical vascular pattern for HCC was
detected in seven (17%) by CE-US, in nine (21%) by CT and in nine (21%) by MRI,
all showing absolute specificity for HCC. Among the 1-2 cm HCC, a typical vascular
pattern was detected at least one imaging technique in 14 (61%), and a coincidental
typical vascular pattern at two techniques (AASLD criteria) in 9 (39%). Among the
1-2 cm LN, sensitivity and NPV were 30 and 54% for CE-US, 39 and 58% for CT,
41 and 59% for MRI, with specificity and PPV for all the techniques.
Conclusion: The study validates the AASLD guidelines for HCC diagnosis in cirrhotic patients. One single contrast imaging technique may be enough to diagnose
HCC not only in 2 cm nodes, but also within 1-2 cm diameter.
B-100
11:51
Hepatocellular carcinoma associated with Budd-Chiari syndrome
B.-K. Kang, D.-I. Gwon, G.-Y. Ko, K.-B. Sung, H.-K. Yoon, J.-H. Shin, J.-H. Kim,
J.-M. Lee, J.-Y. Ohm; Seoul/KR (msbbogri@naver.com)
Purpose: To analyze the clinical and imaging features of hepatocellular carcinoma
(HCC) associated with Budd-Chiari syndrome (BCS).
Methods and Materials: From March 1996 to March 2008, 98 patients with BCS
were retrospectively evaluated. All the patients had membranous obstruction of the
inferior vena cava. Liver nodules were evaluated using serum A-fetoprotein (AFP)
level and imaging features such as computed tomography (CT) and magnetic resonance imaging (MRI). The clinical, radiological and histopathological characteristics
of liver nodules were analyzed.
Scientific Sessions
attenuations of GGNs were measured by using a commercial software. Interscan
variability with theses three different reconstruction algorithms was established
using the Bland and Altman method.
Results: Nodule segmentation was successful in 27 (64%), 42 (100%) and 42
(100%) measurements with B30f, B50f and B60f, respectively. Low success rate of
segmentation with B30 hindered further analysis of reproducibility. In terms of the
volume measurements, interscan variability was -13.50 to 14.38% (mean relative
difference, 0.44%), and -16.27 to 13.63% (mean relative difference, -1.32%) with
B50f and B60f, respectively. With respect to attenuation measurements, interscan
variability was -9.89 to 5.10% (mean relative difference, -2.3%), and -2.86% to
5.49% (mean relative difference, 1.36%) with B50f and B60f, respectively.
Conclusion: With either sharp or medium sharp reconstruction algorithm, variation
of volume and attenuation measurements of GGNs using commercial software is
sufficiently minimal to allow the detection of their clinically relevant growth.
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B-103
Room P
Chest
SS 204
Pulmonary nodule detection and evaluation
Moderators:
N. Karabulut; Denizli/TR
A.R. Larici; Rome/IT
B-101
10:30
Pulmonary nodules with or without ground-glass opacity on 64 detectorsrow CT: Performance comparison of radiologists and computer-aided
detection
M. Yanagawa1, O. Honda1, N. Tomiyama1, S. Yoshida1, A. Inoue1, H. Sumikawa1,
T. Daimon2, T. Johkoh3, H. Nakamura1; 1Suita/JP, 2Shimotsuke/JP, 3Itami/JP
(m-yanagawa@radiol.med.osaka-u.ac.jp)
Purpose: To evaluate the performance of a computer-aided detection (CAD)
system in the detection of lung nodules by 64-detector-row CT compared to visual
interpretation.
Methods and Materials: CT examinations were performed in 48 patients (16 men,
32 women; age range, 42-85 years; mean age, 62.3 years) with suspicious pulmonary
nodules on chest radiographs. Three radiologists independently analyzed the CT
scans, reported the location and pattern (ground-glass opacity [GGO], solid, and
part-solid) of each nodule candidate, and assigned each a confidence score. All CT
scans were also analyzed by these radiologists using the commercially available
CAD system. A reference standard was established by a consensus panel of different
radiologists, who found 229 non-calcified nodules with a diameter of 4 mm or more.
True-positive and false-positive results and confidence levels were used to generate
alternative free-response receiver operating characteristic (AFROC) plots.
Results: The sensitivity of GGO for 3 radiologists (70, 60, and 80%, respectively) was significantly higher than that for CAD system (21%) (McNemar’s test,
p 0.0001). For solid nodules, the areas under the AFROC curves (Az) without
and with the CAD system were significantly different (two-tailed paired t test, p =
0.03). For GGO and part-solid nodules, the Az value with the CAD system were
greater than that without the CAD system, although there were no statistically
significant differences.
Conclusion: Radiologists are significantly superior to this CAD system in the
detection of GGO; however, the CAD system can still play a complementary role
in detecting nodules with or without GGO.
B-102
10:39
Persistent pulmonary ground-glass nodules: Interscan variability of
semiautomated volume and attenuation measurements
C. Park1, J. Goo1, H. Lee1, K. Kim2, C. Lee1; 1Seoul/KR, 2Gyeonggi-Do/KR
(cmpark@radiol.snu.ac.kr)
Purpose: To assess the interscan variability of semiautomated volume and attenuation measurements for pulmonary ground-glass nodules (GGNs) by using
commercial volumetry software.
Methods and Materials: A total of 21GGNs in 17 patients referred for known
GGNs were evaluated with two consecutive non-enhanced chest CT examinations (120 kVp, 100 mAs, collimation 16 x 0.75 mm, slice thickness 1 mm). For the
second limited scan including GGNs, patients got off and on the table to simulate
a follow-up examination. CT images were reconstructed using three different algorithms (sharp, B60f; medium sharp, B50f; and medium smooth, B30f). Volumes and
10:48
Utility of 3D automatic exposure control for low-dose chest CT
examination: Dose optimization for detection of GGO and partly solid
nodule in chest phantom study
K. Matsumoto, Y. Ohno, A. Kono, H. Koyama, Y. Onishi, M. Nogami, D. Takenaka,
K. Sugimura; Kobe/JP
Purpose: The purpose of this study was to determine the utility of 3D automatic
exposure control (AEC) for radiation dose optimization in low-dose chest CT examination at 64-detector row CT system in chest phantom study.
Methods and Materials: A chest CT phantom including simulated focal GGOs
and partly solid nodules, whose diameters were from 2 to 14 mm, was scanned
using a 64-detector row CT with and without 3D AEC. On CT scan with 3D AEC,
SDs were changed from 40 to 200. All other parameters were fixed. Identification
and image quality of each simulated abnormality were visually assessed by two
chest radiologists with a five-point scoring system. Interobserver agreements were
assessed by kappa analysis. Then, identification and image quality of each SD were
compared with that of a fixed tube current by ROC analysis and ANOVA.
Results: All interobserver agreements were substantial (kappa 0.61). When SDs
more than 160 were adopted, Azs of CT scan with 3D AEC was significantly lower than
that without 3D AEC (P 0.05). When SDs more than 100 were adopted, the image
quality of CT scan with 3D AEC was significantly lower than that without 3D AEC
(P 0.05). The lowest radiation doses of CT scan with 3D AEC were determined as
2.59 mSv for identification (SD = 160) and 4.89 mSv for image quality (SD = 100).
Conclusion: 3D-AEC is useful for radiation dose optimization in low-dose chest CT
examination, and is able to achieve at least 50% dose reduction without significant
degradation of image quality as compared with routine clinical protocol.
B-104
10:57
Volumetric measurement of pulmonary nodules at low dose chest CT:
Effect of section thickness and reconstruction kernel on measurement
variability
Y. Wang1, G.H. De Bock1, R.J. van Klaveren2, W.G.J. Tukker1, Y. Zhao1,
M.D. Dorrius1, R. Vliegenthart Proença1, P.M.A. van Ooijen1, M. Oudkerk1;
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Groningen/NL, 2Rotterdam/NL (y.zhao@rad.umcg.nl)
Purpose: To assess the volumetric measurement variability in pulmonary nodules
detected at low-dose chest CT scans using different section thicknesses and
reconstruction kernels.
Methods and Materials: Two hundred small pulmonary nodules identified on 79
low-dose chest CT scans from a lung cancer screening project were selected for
volumetric analysis. All CT data were reconstructed in three different settings with
combination of section thickness and reconstruction kernel: 1 mm & soft kernel,
2 mm & soft kernel, 2 mm & sharp kernel. All nodules were measured three times
with LungCare® software by one radiologist in each setting. The variability of each
setting was assessed with repeatability coefficients, which were calculated using
the Bland and Altman method. The variability between settings was assessed with
relative volume difference (RVD). Univariate analysis was applied to test the impact
of nodule characteristics on variability between settings.
Results: The repeatability coefficients were 8.6, 19.3, and 31.9% for 1 mm & soft
kernel, 2 mm & soft kernel and 2 mm & sharp kernel, respectively. The mean RVD
was 21 p 20% between 1 vs 2 mm and -20 p 21% between soft kernel and sharp
kernel. Size had a significant impact on RVD between settings (p 0.05).
Conclusion: Low-dose CT reconstructed with 1 mm section thickness and soft
kernel provided most repeatable volume measurement. Section thickness and
reconstruction kernel resulted in significant differences in volume measurements,
especially in small nodules.
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Results: Liver nodules were found in 37 patients, 23 of whom had HCC and the
incidence of HCC associated with BCS was 23.5%. Mean age was 48 p 13 years
on diagnosis of BCS, and 49 p 11.6 years on diagnosis of HCC. Increased serum
AFP level had a high accuracy in distinguishing HCC from benign nodules. HCC
showed a female predominance (P = 0.004). The type of HCC was single nodular
in 16 (70%) and multinodular in the remaining 7 (30%) patients. Subcapsular or
exophytic location was documented on all patients, whereas multiple HCCs in three
patients showed intraparenchymal location. Two HCC patients had portal vein invasion, whereas no HCC patients showed bile duct invasion at the time of diagnosis.
The histology of all three HCC samples appeared to be well differentiated.
Conclusion: HCC, associated with BCS, tends to have female predominance
and is of the single nodular type. Most BCS-associated HCCs are located in the
subcapsular and/or exophytic region. Serum AFP appears to have a high utility for
HCC screening in patients with BCS.
Scientific Sessions
B-105
11:06
Linear and volume measurements of pulmonary nodules at different CT
dose levels: Intra- and inter-scan analysis
V.C. Romano1, P.A. Hein1, P. Rogalla1, C. Klessen1, A. Lembcke1, V. Dicken2,
L. Bornemann2, B. Hamm1, H.-C. Bauknecht1; 1Berlin/DE, 2Bremen/DE
(patrick.hein@charite.de)
Purpose: To compare interobserver variability of diameter and volume measurements of pulmonary nodules in intra- and inter-scan analysis using a semi-automated segmentation software on ultra-low-dose computed tomography (ULD-CT)
and standard-dose CT (SD-CT) data.
Methods and Materials: In 33 patients, two chest multi-slice CT (MSCT) data-sets
were consecutively acquired in ultra-low-dose (5 mAs) and in standard-dose technique (75 mAs). Data were analyzed using the segmentation software OncoTREAT
(MeVis, Bremen, Germany). The volume of 229 nodules was determined and the
largest diameter (RECIST) were measured by two radiologists. Interobserver variability was calculated and data compared in an intra- and inter-scan analysis.
Results: Median nodule diameter was 8.2 mm (range: 2.8-43.6 mm, mean:
10.8 mm). Nodule volume ranged between 0.01 and 49.1 ml. With respect to
interobserver variability, the intrascan analysis was not statistically different (p
0.05) between ULD-CT and SD-CT with broader limits of agreement for relative
differences of RECIST measurements (-31.0%; +27.0% mean -2.0% for SD-CT;
-27.0%;+38.6%, mean 5.8% for ULD-CT) than for volume measurements (-9.4%,
8.0%, mean 0.7% for SD-CT; -13%, 13%, mean 0.0% for ULD-CT). The inter-scan
analysis showed broadened 95% confidence intervals for volume measurements
(-26.5%; 29.1% mean 1.3%, and -25.2%, 29.6%, mean 2.2%, respectively) but
yielded in comparable limits of agreement for RECIST measurements.
Conclusion: The variability of nodule volumetry after semiautomated segmentation
as well as nodule size determination by RECIST appears to be independent of
the acquisition dose in the CT data set. This is of importance regarding follow-up
measurements of pulmonary nodules in screening trials using low-doseCT.
B-106
11:15
The effect of CAD on readers with various levels of expertise, analyzing
digital chest radiographs for lung nodules
D. Shaham1, N. Bogot1, I. Leichter1, R. Lederman1, R. Eliahou1, A. Manevitch1,
J. Stoeckel1, M. Dinesh2, M. Acharyya2; 1Jerusalem/IL, 2Bangalore/IN
(dshaham@hadassah.org.il)
Purpose: To evaluate the impact of a CAD-algorithm that detects lung nodules,
on the performance of readers with various expertises.
Methods and Materials: 76 digital chest-radiographs recruited from 3 sites were
retrospectively correlated to CT by 2 independent expert readers, who identified
46 findings (39 nodules [5-30 mm], 7 masses) in 36 radiographs. Each finding
was assigned a five-grade visibility-score. Three blinded-radiologists of different
expertise analyzed all 76 radiographs retrospectively, without and with a prototype
CAD-algorithm (Siemens) that marked suspicious findings on the images.
Results: Using CAD, the resident improved the detection rate from 14 to 16 nodule
cases, while ignoring 2 true CAD-marks. The thoracic radiologist (TR) improved
the sensitivity from 20 to 22 nodule cases while accepting all true CAD-marks. The
general radiologist (GR) ignored 4 true marks, with no change in the nodule detection rate. The resident and TR detected 5 masses without and with CAD, while the
GR improved the detection rate from 4 to 5 masses. The resident detected the most
visible of the nodules, with a mean visibility-score of 4.03, while the visibility-score
for the GR and TR were 3.72 and 3.44, respectively. The aided reading increased
the false findings by 0.29 for the resident, 0.08 for the GR and 0.38 for the TR.
Conclusion: CAD increased detection sensitivity for all readers, but least influenced the
GR. Both the resident and the GR failed to accept all true CAD-marks. The increase in
sensitivity was associated with a higher false mark rate compared to un-aided reading.
B-107
11:24
Evaluating the properties of pulmonary nodules missed by computer-aided
detection (CAD) in chest X-ray imaging
T. Achenbach, C. Dueber; Mainz/DE (achenbac@uni-mainz.de)
Purpose: The knowledge of localizations and morphologies of pulmonary nodules
that are typically missed or detected by CAD systems can help to improve the radiologists’ reading quality. This study aims to recognize the specific morphological
and topographic differences of nodules detected or missed by CAD.
Methods and Materials: We examined pulmonary nodules (n = 51, mean diameter
12 mm) with chest X-ray and MDCT (slice thickness 1-3 mm) as reference within 8
days (median). CAD was performed by the xLNA-system (Philips Medical Systems).
Morphological description was performed as well as assessment of Hounsfield units’
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histogram (mean, maximum, minimum), size, volume and localization (descriptive
statistics and comparison of means, Mann-Whitney U-test).
Results: xLNA detected 23 nodules (45.1%) and missed 28 (54.9%). A total of
13 nodules, which were not detected by the software could not be found by the
radiologist on X-ray images even in retrospective correlation with MDCT. Excluding
these nodules, xLNA detected 23 of the remaining 38 nodules (60.5%). Of the 38
nodules, 17 were classified as obvious and 21 as not obvious. The system found
13 of the 21 not obvious (61.9%). Detection rate was higher in blurred/irregular
nodules (69%) than in round/sharp and denser nodules (56%). The lowest detection
rate was found in the central nodules (2 of 12).
Conclusion: CAD performance is less sensitive in the central areas. Missed
nodules tended to be bigger, denser and more frequently of a round and sharp
morphology than correctly detected nodules. Of the nodules not obvious, 61.9%
were found by the CAD system suggesting a supportive function especially in
vaguely visible nodules.
B-108
11:33
Computer-aided pulmonary nodule detection: Performance of two CAD
systems at different CT dose levels
P.A. Hein, P. Rogalla, C. Klessen, A. Lembcke, V.C. Romano; Berlin/DE
Purpose: To evaluate the impact of dose reduction on the performance of computer
aided lung nodule detection systems (CAD) of two manufacturers by comparing
respective CAD results on ultra-low-dose computed tomography (ULD-CT) and
standard-dose CT (SD-CT).
Methods and Materials: Multi-slice computed tomography data sets of 26 patients
were retrospectively selected for CAD analysis. CT images had been consecutively
acquired at 5 mAs (ULD-CT) and 75 mAs (SD-CT) with 120 kV tube voltage (1 mm
slice thickness). Standard of reference was determined by three experienced readers
in consensus. CAD reading algorithms (pre-commercial CAD system, Philips, Netherlands: CAD-1; NEV, Siemens, Germany: CAD-2) were applied on CT data sets.
Results: Consensus reading identified 253 nodules on SD-CT and ULD-CT.
Nodules ranged in diameter between 2 and 41 mm (mean diameter 4.8 mm).
Detection rates were recorded with 72 and 62% (CAD-1 vs. CAD-2) for SD-CT
and with 73 and 56% for ULD-CT, respectively. Median false-positive rates per
patient were calculated with 6 and 5 (CAD-1 vs. CAD-2) for SD-CT and with 8
and 3, respectively for ULD-CT. After separate statistical analysis of nodules with
diameters of 5 mm and more, detection rates increased to 83 and 61% for SD-CT
and to 89 and 67% for ULD-CT (CAD-1 vs. CAD-2). For both CAD systems, there
were no significant differences between the detection rates for standard- und ultralow-dose data sets (p 0.05).
Conclusion: Dose reduction of the underlying CT scan and consecutive increased
image noise did not significantly influence nodule detection performance of the
tested CAD systems.
B-109
11:42
Evaluation of phenotype of lung cancer using micro-computed
tomography in K-ras transgenic living mice
H. Cho1, S.H. Park1, Y.H. Park2, H.S. Kim1, K.-H. Yoon1, D.-Y. Yu3; 1Iksan/KR,
2
Taegu/KR, 3Taejon/KR (imsilcho@daum.net)
Purpose: The purpose of this study is to evaluate phenotypes of lung cancer using
micro-computed tomography in two types of mK-ras transgenic living mice.
Methods and Materials: mK-ras transgenic mice were generated to express mutant
K-ras gene (GGT12GAT) to lung cells by the direction of surfactant protein C (SPC)
promoter. There are two types of mK-ras transgenic mice according to the genetic
background of the mice. One is B6mK-ras mice with C57BL/6, and the other is
hbmK-ras mice with a mixed hybrid between C57BL/6 and DBA. Five hbmK-ras
mice and three B6mK-ras mice underwent to perform micro-computed tomography.
Three dimensional CT data set were acquired at 10 µm isotropic resolution. We
obtained micro-CT images with one month intervals from sixth months to nine
months of age and then sacrificed for histopathologic correlation.
Results: The first type of mK-ras transgenic mice, hbmK-ras, was revealed to
have multiple nodules of lung on 6 month-CT and the number and size of nodules
were increased on 9 month-CT. On histopathology, the nodules were confirmed as
adenoma and low grade adenocarcinoma. The second type of mK-ras transgenic
mice, B6mK-ras, was revealed to have diffuse consolidation, ground glass opacity
and nodules of lung on micro-CT. On histopathology, numerous alveolar type 2
cells and macrophages were accumulated in the alveolar space of the lung and
the nodules were confirmed as adenomas.
Conclusion: Micro-computed tomography could evaluate phenotypes of lung
cancer model in mK-ras transgenic mice.
Scientific Sessions
B-110
11:51
Purpose: Lung cancer screening trials may provide information about cardiovascular risk. It is not yet clear whether coronary scores from non-gated scans or aortic
scores are more suited for this purpose. We examined whether risk stratification
based on aortic calcifications places patients into similar groups as risk based on
coronary calcium scores derived from non-gated lung cancer screening studies.
Methods and Materials: We included 1,091 baseline scans from subjects participating in a lung cancer screening trial (NELSON). Scans had been acquired at two
centers using 16 x 0.75 mm collimation and a low-dose, non-contrast, non-ECGgated scanning protocol. To control image noise, 3-mm sections were reconstructed
every 1.4 mm. Aortic and coronary calcifications were scored by two observers
(130 HU threshold). For coronary calcifications four atherosclerotic risk categories
were defined based on Agatston score (b10, 11-100, 101-400, 400). Since no
categorization is available for aortic scores we assigned four categories, each
containing the same number of subjects as the respective coronary categories. To
assess the agreement, we calculated linearly weighted kappa statistics (categories)
and Spearman rank correlation coefficients (scores).
Results: The number of subjects was 327, 156, 175 and 433 in the four coronary
risk categories, respectively. The aortic calcium score assigned 526 (48%) subjects
to the same risk category as the coronary score. Linearly weighted kappa statistic
was 0.37, and Spearman rank correlation between scores was 0.51.
Conclusion: While yielding similar results, aortic and coronary calcium scores
cannot be used interchangeably for assessing individual arteriosclerotic risk from
lung cancer screening studies.
10:30 - 12:00
Room Q
Interventional Radiology
SS 209
Upper body interventions
Moderators:
R.W. Günther; Aachen/DE
M. Rupreht; Maribor/SI
B-111
10:30
Laser ablation of lung metastases: Differences in survival according to
tumor entity
C. Rosenberg, K. Bock, N. Hosten; Greifswald/DE
(christian.rosenberg@uni-greifswald.de)
Purpose: The aim of the study was the measuring of survival after laser ablation of
lung metastases from different primary entities. Results were supposed to provide a
patient- and disease-specific outcome evaluation for laser-induced thermal ablation
as a complimentary modality in multimodal cancer therapy.
Methods and Materials: 64 patients underwent CT-guided laser ablative therapy
of pulmonary metastases using a miniaturized internally cooled applicator system
(Monocath, Trumpf Medizinsysteme, Umkirch, Germany). 20 patients suffered from
colorectal, 10 from renal cell carcinoma, 6 from melanoma, 4 from breast carcinoma
metastasis. Diverse entities accounted for metastatic disease in 24 other cases.
Kaplan-Meier analysis was performed.
Results: Median time to death was 12.2 months in all 64 cases, 24.3 months in the
group of patients suffering from renal cell carcinoma and 33.6 months for colorectal
carcinoma metastasis. No therapy-related deaths occurred in 129 procedures.
Pneumothorax drainage was needed in 5% (7/129) of the cases. Parenchymal
bleeding (13%, 17/129) always was self-limited. A median recurrence-free interval
of 10.9 months could be achieved for patients with colorectal metastasis.
Conclusion: Entity of the primary tumor causing pulmonary metastasis influences
prognosis and outcome after image-guided laser ablative therapy. Analogously to
the surgical experience performing local resection of secondary lung malignancies, best results could be achieved colorectal metastasis. Long-term outcome and
postinterventional survival do not necessarily correlate with the disease-specific
primary effectiveness rate.
B-112
10:39
Direct temperature measurements in an ex-vivo human lung model during
thermal ablation
F. Koch1, A. Vietze1, S. Fillmer1, C. Hoffmann1, U. Laskowski2, A. Linder2,
N. Hosten1; 1Greifswald/DE, 2Hemer/DE (franzi_koch@hotmail.com)
Purpose: To evaluate whether temperature measurements during laser ablation
and vital staining can provide information useful for planning treatment parameters
in patients.
Methods and Materials: A total of 39 tumor-bearing lung lobes (non-small cell lung
cancer) were connected to an isolated human lung perfusion model immediately
after surgery. This is an ex-vivo model that allows maintaining near-physiological
conditions (pH, PO2, pCO2, etc). for 5-7 hours by manipulating perfusion and ventilation. During this time period, a laser ablation was performed and the increases
in temperature induced by one or two laser fibers with diffuser tip were measured
invasively. These data were then compared with results of 2.3,5-triphenyltetrazolium
chloride (TTC) and hematoxylin-eosin staining.
Results: Individual temperature curves varied widely. A temperature of 60 °C was
reached in the tissue between two applicators after 5 min; towards the periphery,
at distances of 10 and 20 mm from the applicators, this temperature was reached
after 20 and 24 min, respectively. With one applicator, 60 °C was only surpassed
at 10 mm distance. The mean diameter of the necrotic tissue on TTC stains was
between 35 and 50 mm, larger than that seen macroscopically.
Conclusion: Interindividual variation was high, indicating the need for monitoring
parameters other than ablation time. Temperatures expected to be ablative were
induced by thermal ablation in an ex-vivo lung tumor model. Simultaneous treatment
with multiple applicators significantly increased the efficacy. Necrosis was seen in
areas where the maximum temperature was below 60 °C. Phenomena other than
direct thermal destruction must be responsible for cell death in this zone.
B-113
10:48
CT volumetric assessment of pulmonary neoplasms following
radiofrequency ablation: When to consider a second interference
N.-E.A. Nour-Eldin, T. Lehnert, N.N.N. Naguib, H. Korkusuz, R. Hammerstingl,
T.J. Vogl; Frankfurt a. Main/DE (nour410@hotmail.com)
Purpose: To identify the earliest CT follow-up period to judge the success or
failure of radiofrequency ablation of lung tumors and therefore to consider the
time of re-ablation.
Methods and Materials: Institutional ethical committee board approval was obtained, with informed consent from all patients. This retrospective study included
60 ablation sessions for 6 primary and 54 metastatic lung tumors in 44 patients
(32 males, 12 females; mean age 58.9 years, SD: 15.1). Both unipolar and bipolar
radiofrequency systems were used. Thin-section CT scanning with volumetric
measurement of lesions was performed immediately before ablation as a control
study and at regular post ablation intervals including 24 hours, 3-6 weeks and
3, 6, 9 and 12 months. Volume measurements of lesions were calculated by two
radiologists in consensus using formula for ellipsoid volumes.
Results: The preablation tumor volume ranges from 0.26 to 5.29 cm³ (mean
1.75 cm³, SD 1.59). Statistical correlation between the 12-month post ablation
period volume and the other follow-up periods were used. Nonsignificant (Spearman R = 0.06) and weak correlation (R = 0.44) values were detected between the
post ablation tumor volume in 24 h and the 3-6 weeks periods with the 12-month
period, respectively. The 3-month period showed the earliest strong correlation (R
= 0.72) with the 12-month period. The 6-month period and 9-month period revealed
stronger correlation with the end result (R = 0.86 and 0.93, respectively).
Conclusion: The earliest follow-up period that can predict the one year end result of
ablation is 3 months and earlier periods do not adequately reflect long-term results.
B-114
10:57
Single-center experience in radiofrequency ablation of lung malignancies:
Complications and side effects
L. Crocetti, R. Cioni, E. Bozzi, C. Bartolozzi; Pisa/IT (elenabozzi@libero.it)
Purpose: To determine major and minor complications and side effects of radiofrequency ablation (RFA) of lung malignancies and evaluate prognostic factors for
the development of complications.
Methods and Materials: All patients treated in a single center with RFA for lung
malignancies were entered into a prospective database. Major and minor complications and side effects were reported on a per-session basis.
Results: One hundred and sixty RFA procedures were performed in 114 patients
with 137 malignant lung tumors. Tumor size ranged 0.7-7 cm (mean 2.3 cm p1.0).
CT-guided RFA was performed under conscious sedation by using 150-200 W
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Cardiovascular risk assessment in lung cancer screening scans: Do
coronary and aortic calcium scores yield comparable risks for individual
subjects?
I. Isgum1, P.C.A. Jacobs1, M. Gondrie1, B. van Ginneken1, M. Oudkerk2,
W.P.T.M. Mali1, Y. van der Graaf1, M. Prokop1; 1Utrecht/NL, 2Groningen/NL
(ivana@isi.uu.nl)
Scientific Sessions
generators and multitined expandable electrodes (RITA Medical Systems). One
procedure-related death occurred. Major complications were observed in 13/160
procedures: eleven occurred during or immediately after the procedure (pneumothorax requiring drainage, n=8, and hemothorax treated conservatively, n=3) and two
occurred during the periprocedural time (a pneumomediastinum associated with
subcutaneous emphysema and a pneumothorax requiring surgery). Minor complications were observed in 29/160 procedures (pneumothorax and pleural effusion
not requiring drainage). Side effects were encountered in 51/160 procedures (pain,
limited intraparenchymal hemorrhage, lesion cavitation with bronchial drainage).
Conclusion: Percutaneous RFA of lung malignancies is associated with a low risk
of complications. Lesion size was the only statistically significant prognostic factor
for the development of complications. The procedure-specific major complication
rate is below 10% in experienced hands.
B-115
11:06
Is it possible to predict the end result of radiofrequency ablated lung
tumors by using contrast enhanced MRI follow-up?
N.-E.A. Nour-Eldin, N.N.N. Naguib, T. Lehnert, H. Korkusuz, S. Zangos, T.J. Vogl;
Frankfurt a. Main/DE (nour410@hotmail.com)
Purpose: To determine the effectiveness of contrast enhanced MRI (CE-MRI) lesion
marginal signal intensity to paraspinal signal intensity ratio in the determination of
end result of radiofrequency ablation of pulmonary neoplasms.
Methods and Materials: This retrospective study included 60 ablation sessions
for lung tumors in 44 patients (32 males,12 females; mean age 58.9 y). CE-MRI
scanning of pulmonary tumors was performed 1 week before ablation (as a control
study) and in the post ablation follow-up on 24 h, 3-6 weeks, 3 months, 6 months,
9 months and 12 months. The lesion marginal enhancement signal intensity to
paraspinal muscle signal (LMS) ratio was measured using T1 Fast Low Angle Shot
2 Dimensional (FLASH-2D) trans-axial breath holding sequence, using 1.5 Tesla
MRI unit as a parameter of assessment. Thin-section CT scanning with volumetric
measurement of lesions was performed at the same time periods. The correlation
between the LMS ratio at each follow-up period with the 12 month end result post
ablation follow-up tumor volume.
Results: The preablation tumor volumes range 0.26-5.29 cm3 (mean 1.75 cm³,
SD1.59), while 12 month post ablation tumor volume range 0.06-21.5 cm3. Weak
correlation was detected between the LMS ratios and 12 month CT volumetric result
in 24 h post ablation and 3-6 weeks (Spearman R:0.1, p=0.64 and R:0.2, p=0.08,
respectively). A strong correlation between the LMS ratios and the 12 month end
result CT tumor volume on the follow-up period on 3 months (R:0.63, p=0.001), 6
months (R:0.7, p=0.0002), 9 months (R:0.68, p=0.0003) and 12 months (R:0.75,
p=0.0). LMS ratio 1 was associated with post ablation reduction of tumor volume,
while LMS ratio 1 were associated with post ablation increase of tumor volume.
Conclusion: MRI contrast enhanced lesion marginal signal intensity to paraspinal
signal intensity ratio follow-up can effectively determine the tumor course post
ablation.
B-116
11:15
Pulmonary hemorrhage complicating radiofrequency ablation, from mild
haemoptysis to life-threatening pattern
N.-E.A. Nour-Eldin, S. Zangos, N.N.N. Naguib, K. Eichler, H. Korkusuz,
M.G. Mack, T.J. Vogl; Frankfurt a. Main/DE (nour410@hotmail.com)
Purpose: To assess risk factors and extent of pulmonary hemorrhage and haemothorax complicating radiofrequency (RF) ablation of pulmonary neoplasms.
Methods and Materials: Institutional ethical committee review board approval was
obtained, with informed consent from the patients. This study involved 248 ablation
sessions for lung tumors (20 primary lesions and 228 metastatic lesions) in 164
patients (92 males, 72 females; mean age 59.7 years) in the time period between
March 2004 and January 2008. The exclusion criteria for ablation therapy were
lesions with maximal diameter more than 5 cm, lesions more than five in number,
bleeding tendency (prothrombin concentration less than 75%, platelets count less
than 50,000/cc). Both unipolar and bipolar radiofrequency systems were used
under CT guidance.
Results: In our study, the incidence of intraparenchymal pulmonary haemorrhage
(perilesional and in the track between the site puncture and the lesion) and pleural
effusion were 19.3% (48 of 124 sessions) and 4% (8 of 124 sessions), respectively.
These complications were treated conservatively with complete resolution within
3-6 weeks.Univariate analysis of contributing risk factors revealed: lesion size (P =
0.015), pathology type (P = 0.007), direct subpleural lesions (P 0.0001), technical
factors necessitating excessive manipulations (including direct retrocostal lesions,
small size lesions and angular application of the electrode needle) and multiple
electrodes applications.
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Conclusion: Pulmonary haemorrhage and pleural effusion are self-limiting complications of radiofrequency ablation of lung neoplasms when precautions against
risk factors are strictly followed.
B-117
11:24
Prevention of pneumothorax following transthoracic needle biopsy (TTNB):
Feasibility study of safety and effectiveness of a new sealant system
S.G. Lindemayr1, M. Kreuter2, R. Hammerstingl1, T.J. Vogl1; 1Frankfurt a. Main/DE,
2
Heidelberg/DE (S.Lindemayr@gmx.net)
Purpose: To determine the safety effectiveness of a single transthoracic injection of PneuSeal sealant along the needle track in the lung parenchyma pleura
for prevention of a pneumothorax (PTx) following TTNB compared to baseline
historical controls.
Methods and Materials: Prospective, non-randomized, historical controlled
2-center-study. 38 patients underwent TTNB of the lung, followed by injection along
the needle track of PneuSeal (PneumRx, Mountain View, CA). Chest radiograph
CT was used to detect PTx within 3 14 days post biopsy. Hemoptysis and change
from baseline spirometry clinical status were recorded. Mean age was 65.6 (38-79)
years. Mean lesion diameter was 3.2 cm (range: 0.5 8.6 cm), mean lesion depth
was 1.4 cm (range: 0-4.3 cm).
Results: 1/38 (2.6%) required chest venting. 1 patient (pt) experienced parenchymal
bleed pre-sealant injection, which stopped post-injection. 1 pt suffered hemoptysis
pre-injection, with no additional pts experiencing hemoptysis, post-injection. 11/38
(29%) experienced a small PTx (range: 0.3 1.9 cm) post-sealant injection, 2/38
(5.3%) had medium PTx (1-2 cm) 0/38 (0%) had large ( 2 cm) PTx. This favorably
compares to historical data: of 8.3% small PTx, 8.3% medium PTx 5.6% large PTx.
Historical chest venting rate is 5.6%. All pts tolerated the sealant without SAEs. No
inflammatory reactions or changes in mean FEV1-values were found after treatment.
1 pt experienced significant pain during the procedure for unknown reason.
Conclusion: Injection of PneuSeal appears to reduce the rate of significant PTx
chest tube placement and appears safe well tolerated. Multicenter studies are
ongoing.
B-118
11:33
Percutaneous treatment of massive pulmonary embolism: Mechanical
fragmentation and fibrinolysis
S. Pieri, P. Agresti; Rome/IT (stepieri@excite.it)
Purpose: Massive pulmonary embolism is a severe clinical condition that requires
prompt therapeutic intervention. We report our experience with a hybrid treatment
involving systematic fragmentation of the embolus with an angiographic catheter
associated with fibrinolytic therapy over the following days.
Methods and Materials: From 1999 to 2005, we treated 172 patients with massive
pulmonary embolism. We used the same angiographic catheter for mechanical
fragmentation and for administration of the fibrinolytic agent (24-72 h). Results were
assessed on the basis of changes in mean pulmonary artery pressure.
Results: After fragmentation with the angiographic catheter, we observed four types
of haemodynamic behaviour: in 69 patients (41.4%), mean pulmonary artery pressure fell rapidly below 30 mmHg; in 39 patients (23.1%), two passes were required
to achieve the same result; in 32 patients (19.5%) three passes were required. In the
remaining 26 patients (15.8%), at no time did the mean pulmonary artery pressure
fall below 35 mmHg. The only two deaths occurred in this last group.
Conclusion: Mechanical fragmentation with the angiographic catheter and administration of fibrinolytic agents effectively brought about a rapid improvement in
patients’ clinical status by moving the embolus towards the periphery.
B-119
11:42
In vivo radio frequency ablation (RFA) in small breast cancer: Preliminairy
results
B.G. Looij1, D.L. Kreb2, J.C. van der Linden1, M.F. Ernst1, J.F.M. Pruijt1,
K. Bosscha1, G.J. Jager1, M.J.C.M. Rutten1; 1's-Hertogenbosch/NL, 2Utrecht/NL
(b.looij@gmail.com)
Purpose: Radiofrequency ablation may be an effective alternative treatment option
for breast cancer patients unsuitable/unfit for surgery. This study was designed
to assess the feasibility, efficacy and safety of radio frequency ablation (RFA) in
small breast cancer.
Methods and Materials: Eight patients with solitary small (< 1,5 cm) breast cancer
were included. All tumors were invasive ductal carcinoma. RFA was performed
under general anaesthesia followed by lumpectomy or mastectomy. A 17-gauge
Cool-Tip RF needle was placed in the centre of the tumor using real-time ultrasound
guidance. The tumor was ablated for 12 minutes. Whole mount sectioning of the
Scientific Sessions
B-120
11:51
Clinical efficacy of percutaneous ethanol injection of hypervascular cold
nodules of the thyroid
L. Tarantino1, I. Sordelli2, A. De Rosa2, F. Esposito2, M. Perrotta1, C. Ripa2,
A. Villanacci3, D. Parmeggiani3, P. Sperlongano2; 1Frattamaggiore/IT, 2Naples/IT,
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Rome/IT (lucianotarantino@ecografiainterventistica.it)
Purpose: Efficacy of percutaneous ethanol injection (PEI) as a technique for reducing neck swelling and subjective symptoms due to cold thyroid nodules.
Methods and Materials: 42 patients (36 females, 6 males; age 16 - 66 years) with
a single or multiple cold nodules of the thyroid (volume range 13 - 90 ml; mean:
23 ml), showing hypervascularity at color-doppler US, underwent ultrasound guided
PEI. 25/42 (59%) of the patients complained the following symptoms: sensation
of airway obstruction difficult swallowing pain. All nodules underwent echo guided
fine needle biopsy (3 passages for nodule) to rule out malignancy. Effectiveness of
PEI was evaluated with color-power-Doppler follow-up and assessment of patients’
satisfaction by a questionnaire.
Results: Fine needle biopsy excluded malignancy in all cases. We performed
2-11 sessions of PEI per patients with injection of 3 - 14 ml of ethanol per session
(total amount per patient: 17 - 120 ml). During the follow-up ranging 12 - 44 months
(median: 26 months), all nodules showed a marked decrease of the pretreatment
volume (50 - 95%). 6 - 12 months after the treatment, 29 patients showed a normal neck shape and the other 13 patients referred the aesthetical results as very
“satisfying”. 21/25 (84%) of symptomatic patients referred complete disappearance
of subjective symptoms. No complication was reported.
Conclusion: PEI seems to be an effective and safe therapy for treatment in patients
with neck swelling and symptoms due to cold nodules of the thyroid.
10:30 - 12:00
Room R
Cardiac
SS 203
Coronary CT angiography: Reconstruction
algorithms and dose reduction
Moderators:
D. Fleischmann; Stanford, CA/US
R. Marano; Rome/IT
B-121
10:30
Biological X-ray effects in coronary CT angiography: Comparison of helical
with sequential scan modes
M.A. Kuefner, S.A. Schwab, S. Azoulay, K. Anders, S. Achenbach, W. Bautz,
M. Löbrich, M. Uder; Erlangen/DE (michael.kuefner@uk-erlangen.de)
Purpose: Sequential scan modes should lead to a reduction of physical dose in
coronary CT angiography (CTA) compared to helical scans. The established physical
dose parameters determine exposition, but do not assess biological X-ray interactions. Determination of DNA double-strand breaks (DSBs) provides an accurate
estimate of biological radiation effects. Therefore, it was our aim to compare in-vivo
DNA lesions introduced during helical with sequential CTA.
Methods and Materials: 31 patients were examined with various scan protocols
using a 64-slice dual-source (helical scan: 100-120 kV, 330-438 mAs/rot, pitch
0.2-0.39, ECG-modulated tube current) or a 128-slice single-source CT scanner
(sequential scan: 120 kV, 150-300 mA, table feed 34.5 mm). Blood lymphocytes
were isolated, stained against the phosphorylated histone variant YH2 AX, and
DSBs were visualised using fluorescence microscopy.
Results: Dose length product (DLP) ranged from 155 to 402 (mean 249 mGy*cm)
in sequential and from 508 to 1700 mGy*cm (mean 958 mGy*cm) in spiral scans
(p=0.00003). Mean number of DSBs 30 minutes after CTA ranged from 0.11 to 0.71
per cell and was significantly lower after sequential (0.14 DSBs/cell) compared to
helical scans (0.39 DSBs/cell, p=0.0005). Number of DSBs showed a correlation
to DLP (R=0.73). Using a helical scan mode a 100 kV protocol led to a reduction
(p 0.05) whereas additional calcium scoring led to a significant elevation of DSB
levels (p=0.04).
Conclusion: A sequential coronary CTA can lead to a significant reduction of DLP
and X-ray induced DNA damages compared to helical scans.
B-122
10:39
Biological dose estimation in coronary angiography by determination of
X-ray induced DNA double-strand breaks
S.A. Schwab1, M.A. Kuefner1, S. Brunner1, S. Azoulay1, C.D. Garlichs1, W. Bautz1,
M. Loebrich2, M. Uder1; 1Erlangen/DE, 2Darmstadt/DE
(Siegfried.Schwab@uk-erlangen.de)
Purpose: During coronary angiography patients are exposed to rather high X-ray
doses and interventional cardiologists to scattered radiation. Physical dose parameters can determine exposition, but do not adequately evaluate dose deposition
in the patient. DNA double-strand breaks (DSBs) are among the most significant
genetic lesions introduced by ionising radiation. The aim of this study was to assess
radiation induced DSBs and to estimate biological dose in patients and cardiologists after angiography.
Methods and Materials: Blood samples were taken from 37 patients undergoing
coronary angiography and from 3 interventional cardiologists before and after the
examinations. DSBs were visualised using immunofluorescence microscopy after
staining against the phosphorylated histone variant gamma-H2 AX. Radiation dose
to the blood was estimated by relating in-vivo number of DSBs to those of individual
in-vitro irradiated samples (50 mGy).
Results: Dose area product (DAP) ranged from 1337 to 12448 µGy*m2, fluoroscopy
time ranged from 1.5 to 14.4 minutes. In all patients, an irradiation induced increase
of DSBs was detected. Number of DSBs at the end of fluoroscopy ranged from
0.49 to 1.08 per cell, thereafter a rapid loss of foci was observed. Radiation dose
to the blood ranged from 23.4 to 56.4 mGy. In cardiologists, no significant increase
of DSBs during a working day was found.
Conclusion: Gamma-H2 AX immunofluorescence microscopy is suitable for biological dose estimation in coronary angiography. High damage levels were found
in patients, whereas after a working day in interventional cardiologists no biological
X-ray effects due to scattered irradiation could be detected.
B-123
10:48
Coronary artery calcium quantification based on virtual non-contrast
enhanced dual energy CT coronary angiography
F. Schwarz, G. Bastarrika, B. Ruzsics, A. Sterzik, R. Brothers, P. Costello,
U.J. Schoepf; Charleston, SC/US (schwarz@musc.edu)
Purpose: Coronary CT angiography (CCTA) is often performed in conjunction with
non-contrast coronary artery calcium scoring. We aimed to investigate whether
coronary calcium can be quantified based on virtual non-contrast reconstructions
obtained from contrast-enhanced dual energy CCTA.
Methods and Materials: With IRB approval, 25 patients (18 male, mean age
60.4p11.2 years, mean heart-rate 60.9p11.5 bpm) underwent conventional noncontrast coronary calcium scoring followed by contrast-enhanced CCTA performed
in dual energy mode (A-tube: 140 kV, B-tube: 100 kV). From the dual energy CCTA
data, 3 mm sections of both energy spectra were reconstructed. Virtual non-contrast
series were generated using commercially available software (Syngo-Dual-Energy,
Siemens). Image series were analyzed in random order by two blinded, independent
observers who performed calcium quantification on both, conventional calcium scoring scans and virtual non-contrast reconstructions. Results were used to generate
a regression model correlating the Agatston scores obtained with both methods.
Results: Mean Agatston scores from virtual non-contrast enhanced reconstructions
were systematically lower (mean 181p402) than from conventional non-contrast
scans (mean 555p843). After log-transformation virtual and conventional scores
followed normal distribution and showed excellent linear regression (R=0.94,
p 0.001). Predicted Agatston scores using this regression model and conventional
Agatston scores demonstrated excellent linear correlation (R=0.90, p 0.0001,
n=25) and agreement (CCC=0.85 [0.73-0.92]).
Conclusion: There is excellent correlation between coronary calcium scores based
on virtual non-contrast reconstructions from dual energy CCTA data and conventional calcium scoring. Therefore, this approach may have potential to quantify coronary artery calcium and assess coronary artery anatomy with a single dual energy
CCTA scan without the need for a prior non-contrast calcium scoring scan.
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ablated region was performed and the specimens were stained with cytokeratine
8 (C-8) method to assess tumor cell viability.
Results: Mean patient age was 67 years (range 56-77). All procedures were
technically successful. A median end temperature of 65°C (range 55°-80°) was
reached. At histopathological examination the diameter of the ablated region
ranged from 23 to 44 mm (mean 30) and the mean tumor size was 14 mm (range
8-24). C-8 staining revealed complete cell death in all 8 lesions. One procedure
was complicated by a superficial skin burn as a result of heat conducting to the
skin along a metal localisation wire.
Conclusion: (1) US guided RFA can result in complete cell death in small breast
cancer. (2) US guided RFA in small breast cancer is a safe procedure but can lead
to superficial skin burn.
Scientific Sessions
B-124
10:57
320-slice computed tomography using minimal amount of contrast
material and low radiation dose: Feasibility and resulting image quality
A. Lembcke, P. Hein, M. Wagner, C. Kloeters, B. Hamm, P. Rogalla; Berlin/DE
(Alexander.Lembcke@gmx.de)
Purpose: To establish a scanning protocol and to evaluate the resulting image
quality in 320-slice cardiac CT with 35 ml of contrast material and low radiation
exposure.
Methods and Materials: 24 patients (16 males, 36-74 years, body mass index
18-26, heart rate 54-69/min) were scanned with array detector CT (320 detector
rows, AquilionOne, Toshiba) at 100 kV, 300-450 mA, 0.5 mm collimation with 0.25
reconstruction increment, 350 ms rotation time. A single beat acquisition with
punctual exposure at 75% of the RR-interval was performed following intravenous
administration of 35 ml iodinated contrast material at a flow rate of 7.5 ml/s. Scanning was initiated using real-time bolus tracking. Vessel attenuation, image noise
and contrast-to-noise ratio were measured and the overall image quality and
diagnostic confidence was rated.
Results: All scans had diagnostic quality. Attenuation values (density in the aortic
root) ranged between 312 and 523 HU, image noise (standard deviation in aortic
root) ranged from 28 to 56 HU and respective contrast-to-noise ratio ranged from
7.8 to 16.3. All data sets were rated to have good (n = 14) or excellent image
quality (n = 10)) and diagnostic confidence was rated as high (n = 11) or very high
(n = 13). Calculated radiation dose (based an the displayed dose-length-product)
ranged between 1.3 and 2.2 mSv.
Conclusion: 320-slice CT offers the possibility to dramatically reduce radiation dose
in cardiac CT. At the same time, the amount of contrast material can be reduced,
mainly due to the snapshot like data acquisition.
B-125
11:06
Effective patient radiation doses and skin organ doses at coronary CT
angiography and invasive coronary angiography
A. Sterzik, J. Abro, U.J. Schoepf, W. Huda; Charleston, SC/US (sterzik@musc.edu)
Purpose: To compare overall effective patient radiation doses and skin doses at coronary CT angiography (cCTA) with those at invasive coronary angiography (ICA).
Methods and Materials: A total of 104 consecutive patients underwent cCTA
on a 64-slice CT scanner. Effective radiation dose was quantified using the Dose
Length Product (DLP). Average skin organ dose was quantified using the volume
Computed Tomography Dose Index (CTDIvol). A total of 102 different consecutive
patients underwent ICA. Data were obtained pertaining to a reference dose 15 cm
from the isocenter and to the number of runs, fluoroscopy time and Kerma-Area
Product (KAP).
Results: Mean DLP for cCTA was 1,120 p 200 mGy-cm with an average effective dose equivalent to 21 mSv. For ICA, the mean number of imaging runs was
12.2 p 7.6 and the mean fluoroscopy time was 9.9 p 11.5 min. Average KAP was
84.1 p 83.7 Gy-cm2 with an average effective dose equivalent to 15 mSv. The median
CTDIvol was 58 mGy with 10th and 90th percentiles at 58 and 69 mGy, respectively.
For cCTA, the skin dose is approximately 2.5 times higher than CTDIvol and the
average skin dose is thus estimated at ~150 mGy. For ICA, the average reference
point dose was 1,420 p 1,440 mGy. The median reference point dose was 960 mGy
with 10th and 90th percentiles at 300 and 2,940 mGy, respectively.
Conclusion: Average effective patient radiation doses at cCTA are somewhat
higher than those of ICA, but the latter show much more variation between patients.
Average skin doses at ICA are an order of magnitude higher than those associated with cCTA and may exceed the threshold dose (2,000 mGy) for inducing
skin damage.
B-126
11:15
Lower radiation dose with 320 MDCT volume coronary angiography using
prospective ECG gating (pECG)
J. Hoe; Singapore/SG (jhoe@pacific.net.sg)
Purpose: To determine radiation dose using 320MDCT volume scanning, which
can be performed using pECG.
Methods and Materials: 201 patients were scanned using 100 or 120 kVp tube
voltage. Radiation dose was measured as extended dose length product (DLPe)
and estimated effective dose (mSv) calculated. DLPe not DLP is used because of
16 cm scan coverage with 320MDCT. For heart rates (HR) 65 bpm, exposure
phase was 65% till end of R wave of cardiac cycle, using a one heart beat (HB)
acquisition. For HR 66-85 bpm scanning used a 2 or 3 HB scan.
Results: For one HB acquisition, with HR 65 bpm and with no arrhythmias, the
mean effective dose was 6.9 mSv p2.0 mSv (lowest dose was 1.9 mSv). The per-
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centage reduction in effective dose (difference between predicted DLP and DLPe
using pECG) was -51p11%. Qualitative image quality was also assessed to be in
good to excellent range while uniform image quality was assessed to be in low to
medium mottle range. Mean estimated radiation dose for patients scanned using
2 or 3 HB scans was 18.5 mSv.
Conclusion: pECG scanning using 320MDCT, in patients with HR 65 bpm,
results in significantly lower radiation compared with conventional 64MDCT and
similar doses to 64MDCT with step and shoot scanning using padding. Heart rate
reduction using betablockers is necessary to ensure one HB scan to achieve the
lower radiation dose. Further reduction in dose can likely be achieved by narrowing
the exposure phase currently being used with also more consistent use of lower
tube voltages e.g. 80 & 100 kVp.
B-127
11:24
Impact of heart rate on radiation dose in ECG-gated dual-source-CT
coronary angiography
P. Blanke, U. Saueressig, G. Pache, T. Bley, E. Kotter, M. Langer; Freiburg/DE
(philipp.blanke@uniklinik-freiburg.de)
Purpose: Dual source CT (DSCT) scanners allow for an increase in pitch with
increasing heart rates. The effect of increasing heart rate on the dose performance
of DSCT coronary angiography was investigated.
Methods and Materials: 95 consecutive patients underwent retrospectively gated
DSCT coronary angiography (Siemens Definiton) with ECG controlled pulsing windows
with reduced systolic tube current and automatic pitch adaption (120 kV, 2 x 350 mAs
maximum tube current, minimal tube current 4% of maximum outside the pulsing window). Depending on heart rate, two different pulsing windows were employed: a narrow
window around 70% of RR cycle in patients with heart rates below 75 bpm (n=52),
or a wider window between 35 to 70% of RR cycle for heart rates between 75 and
90 bpm (n=43). CTDI, DLP, and effective dose were compared between both groups.
Diagnostic quality of the images was assessed on a per segment basis.
Results: Radiation dose exposure was significantly higher in the group with the
wider pulsing window compared to the narrow pulsing window; CTDI 42.6 p 9.3
vs. 31.5 p 8.7 mGy; effective dose 11.1 p 3.3 vs. 7.9 p 2.6 mSv, p 0.001. Both
systolic and diastolic reconstructions were needed for diagnostic assessment in
the group with the wider pulsing window.
Conclusion: The dose increment caused by a wider pulsing window at higher heart
rates seems to override the dose saving effect of higher pitch values leading to an
overall higher radiation dose in patients with higher heart rates.
B-128
11:33
Quantification of radiation dose savings in cardiac-computed
tomography using prospectively triggered scan mode and ECG pulsing:
A phantom study
L. Lehmkuhl1, D. Gosch1, H.-D. Nagel2, T. Kahn1, M. Gutberlet1; 1Leipzig/DE,
2
Hamburg/DE (lukas.lehmkuhl@med.uni-leipzig.de)
Purpose: The aim of this phantom study was to quantify radiation dose reduction in cardiac computed tomography (CT) using a prospectively triggered scan
mode (“step-and-shoot”) in comparison to a retrospectively ECG-gated helical
scan mode.
Methods and Materials: Absorbed organ doses in cardiac CT scans (64-row)
were quantified using an anthropomorphic male Alderson phantom. A total of 74
thermoluminescence dosimeters (TLD) were placed into the phantom (63) and on
its surface (11). Three different scan protocols were applied, and each measurement was performed three times. Protocol 1: retrospectively ECG-gated mode
(800 mAs;120 kV; scan length = 12.4 cm; pitch = 0.2; rotation = 0.4 sec) as used in
clinical routine. Protocol 2: similar to protocol 1 using additional ECG pulsing of the
tube current with dose maximum at 75% of the R-R interval. Protocol 3: prospectively
triggered mode (“step-and-shoot”), with data acquisition at 75% (R-R). To guarantee
equal image quality, image noise and mAs settings of the prospectively triggered
mode were evaluated in a pre-test. Tube current was then set to 210 mAs. The
scan length and tube voltage were similar to the other protocols. In all protocols,
an ECG simulator was used (heart rate 60/min).
Results: Compared to the retrospectively ECG-gated mode, mean relative organ
doses could be reduced to about 43.8% using ECG pulsing and about 75.9%
using the prospectively triggered mode, respectively. The range of dose savings
varied from 33.6 to 48.6% using ECG pulsing and from 65.3% to 87.2% using
step-and-shoot mode.
Conclusion: TLD measurements approved the relevance of dose-saving protocols
in cardiac CT. Prospectively triggered cardiac CT, with the recently introduced
step-and-shoot protocol, demonstrated the best performance compared to ECG
pulsing with a dose reduction of up to 87.2%.
Scientific Sessions
B-129
11:42
Impact of advanced reconstruction and workflow techniques on coronary
CT diagnostic and productivity performance: A prospective study
B. Merlino, R. Marano, A. Simeone, G. Savino, L. Natale, L. Bonomo; Rome/IT
(bmerlino@rm.unicatt.it)
B-130
11:51
The impact of high temporal resolution on low heart rates: Comparison
between dual-source and 64-slice CT coronary angiography
S. Baumüller; Zürich/CH (stephan.baumueller@usz.ch)
Purpose: To compare the diagnostic performance of dual-source computed
tomography (DSCT) and 64-slice CT for the assessment of significant coronary
artery stenoses at low heart rates (HR).
Methods and Materials: 200 patients with HR 65 bpm were enrolled in this
retrospective study. Each of the 100 patients underwent dual-source and 64-slice
CT coronary angiography. Each patient underwent invasive coronary angiography
(ICA) within 4 weeks of CT. Two blinded observers independently assessed image
quality of all coronary segments with a diameter r1.5 mm as being assessable or
not, and assessed presence of significant stenoses (defined as luminal diameter
narrowing of 50%) in each coronary segment. Patient-based accuracy, sensitivity,
specificity, positive predictive (PPV) and negative predictive value (NPV) for the
detection of significant coronary stenoses with CT were calculated using ICA as
standard of reference.
Results: No significant differences were found regarding gender (p=0.88), age
(p=0.54), body weight (p=0.9) cardiovascular risk profile (p=0.90), mean HR
(p=0.18), variability of HR (p=0.14), Agatston-score (p=0.88) between the patients
in the DSCT and those in the 64-slice CT group. There was no significant difference in the rate of non-assessable coronary artery segments between 64-slice
CT (1.8%, 25/1387) and DSCT (1.0%, 14/1405; p=0.08). Patient-based accuracy,
sensitivity, specificity, PPV, and NPV, respectively, were as follows: 97, 96, 97, 83,
100% at DSCT and 95, 92, 95, 75, 99% at 64-slice CT. Overall accuracy (p 0.05)
as well as specificity (p 0.05) were significantly higher with DSCT as compared
with 64-slice CT.
Conclusion: In patients with low HR, the higher temporal resolution of DSCT
results in an improved diagnostic performance when compared to 64-slice CT
coronary angiography.
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Purpose: To assess advanced 3D workstation (WS) solutions impact on workflow,
diagnostic performance and productivity in coronary CT angiography.
Methods and Materials: A total of 82 CT data sets (64-MDCT, VCT GE; Milwaukee,
MI, USA) were randomly evaluated by 2 experienced observers using two different
3D WS system: TeraRecon, Inc Intuition (WS-A) and Advantage 4.3-GE (WS-B),
according to a predefined standard assessment protocol. For each study, several
parameters were recorded related to technical (load-to-record, VRT, MPR, MIP,
editing, standard projection rendering times), workflow (step-by-step timing, GUI
user response, recon and analysis time), diagnostic (lesion number and location,
grading) and ergonomic performance (user required action-URA time). An overall
3D time and a semiquantitative user score (1-poor to 4-high) were also recorded.
Results: No significant difference in accuracy was observed. Nevertheless, WS-A
was slightly faster in loading and rendering data and more effective in managing
progressive processing steps due to the optimized integration in the GUI environment (22% reduced time, p 0.05). URA was correspondently minimized for WS-A
(30%, p 0.05). The need for radiologist to review initial recon data was also lower
for WS-A, mostly due to the easiness to correct data "on-the-fly" during recon and
view them even from thinner network client. Overall time from scanner to report
was 23 min for WS-A, 38 min for WS-B (p 0.01).
Conclusion: Fast scanner provides huge amount of data, whose management
is critical for overall performance and productivity. Improvement of hardware, but
especially more powerful and refined software solutions are the major determinant
of coronary CT success.
14:00 - 15:30
Liver: MR diffusion and spectroscopy
Moderators:
G.M. Bongartz; Basle/CH
M. Lewin; Paris/FR
B-131
14:00
Contribution of echo planar imaging with diffusion-sensitising gradient on
detection of small colorectal liver metastases
M. Mignon, F. Zech, Y. Maréchal, J.-F. Gigot, C. Hubert, L. Annet; Brussels/BE
(manumignon@hotmail.com)
Purpose: To assess the contribution of diffusion-weighted sequence (DW-EPI)
during a standard Gadolinium-enhanced magnetic resonance examination (MRE)
for colorectal liver metastases (CLM) detection.
Methods and Materials: Sixty-two MRE of patients surgically treated for CLM were
retrospectively reviewed. The standard examination included TSE T2-weighted fat
saturated, T1-weighted dual-echo and dynamic T1-weighted Gadolinium-enhanced
sequences. DW-EPI (b = 20 sec/mm2) was additionally performed for all patients.
Three independent observers reviewed the MRE first without and then with the
additional DW-EPI sequences. The number, diameter, nature and localisation of all
detected lesions were recorded. The inter-observer reproducibility was calculated.
The sensitivity of MRE without and with DW-EPI was assessed considering the
number and the size of the lesions. The positive predictive value was calculated.
Pathological sampling was obtained for each CLM.
Results: Pathological analysis recorded 150 metastases. The inter-observer
reproducibility was high without (r = 0.849) and with DW-EPI (r = 0.870), with no
significant difference between the two methods. The sensitivity was significantly
influenced by DW-EPI (p = 0.0046) and by the number of lesions (p = 0.00083).
No significant difference was found for lesions larger than one centimeter. The
mean value of false positive per patient was 0.089 without DW-EPI and 0.202 with
DW-EPI (p = 0.0073).
Conclusion: The additional DW-EPI sequence to a standard Gadolinium-enhanced
MRE improves the sensitivity for infracentimetric and numerous CLM at the cost
of a decrease in the specificity.
B-132
14:09
Detection and characterization of liver lesions in patients with
gastrointestinal cancer with diffusion-weighted MR imaging
M. Eiber, K. Holzapfel, M. Bruegel, C. Ganter, J. Gaa, E. Rummeny; Munich/DE
(matthias.eiber@gmx.de)
Purpose: To compare DW-MRI with multi-detector row CT (MS-CT) for lesion
detection in patients with gastrointestinal cancer and to analyze DWI-MRI for lesion characterization.
Methods and Materials: We evaluated 116 consecutive patients with colorectal
(n = 82), gastric (n = 16) or oesophageal adenocarcinoma (n = 18) and suspected
liver metastases with MRI at 1.5 T and contrast-enhanced 64-row MS-CT. For MRI,
T1- and T2-weighted pulse sequences as well as DWI with respiratory-triggered
single-shot echo-planar-imaging (SSEPI: TE 69 ms, SL 5 mm, b-values 50, 300 and
600 s/mm2) were employed. Images were analyzed by two experienced radiologists
blinded to the clinical results. Results for lesion detection of MS-CT and DWI-MRI
were compared using ROC analysis. In 60 patients, diffusion coefficients (ADCs)
were calculated for lesion differentiation.
Results: For lesion detection, ROC analysis showed superiority (P b 0.01) of DWI
as compared to MS-CT. Especially, metastases with diameters of smaller than 1 cm
were better detected with DWI-MRI as compared to MS-CT (P b 0.01). Results for
differentiation showed mean ADC values of 1.24 for normal liver, while malignant
tumors had ADCs of 1.04-.1.22 and benign lesions such as hemangiomas or cysts
of 1.9-3.0, respectively. Furthermore, relevant therapeutic changes were made in
20 % of patients, based on DWI.
Conclusion: MR imaging using DWI is more sensitive than multi-detector row
CT in the detection and characterization of liver metastases from colorectal,
pancreatic, esophageal or gastric cancer. Thus, it can be used for optimal treatment planning.
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Scientific Sessions
B-133
14:18
Detection of liver metastases in patients with malignant pancreatic tumors
by diffusion-weighted MR imaging (DWI)
A.A. Fingerle, K. Holzapfel, C. Reiser-Erkan, M. Bruegel, E.J. Rummeny, J. Gaa;
Munich/DE (alexander.fingerle@gmx.de)
Purpose: To evaluate the usefulness of diffusion-weighted MR imaging (DWI)
for the detection of liver metastases in patients with malignant pancreatic tumors
compared to MDCT.
Methods and Materials: In 31 patients with pancreatic masses diffusion-weighted
MR imaging and MDCT of the liver were performed. For DWI, a respiratory-triggered,
single-shot echo planar imaging (SSEPI) sequence was acquired (TR = d, TE =
69 ms, matrix 256 x 256, slice thickness 5 mm, GRAPPA 2, b-values 50, 300 and
600 sec/mm2) combined with navigator echo technique (PACE). Imaging results
were correlated with histopathology and intraoperative US-findings.
Results: In 31 patients a total of 31 focal liver lesions in MDCT (14 benign, 7
malignant, 10 unclear) and 52 in DWI (39 benign, 9 malignant, 4 unclear) were
detected. In comparison to histopathology and intraoperative US-findings 33.3 %
of liver metastases were detected by MDCT whereas DWI could detect 88.9 % of
liver metastases. Specificity was 77.8 % for MDCT and 97.5 % for DWI. Therefore,
DWI would have altered the therapeutic management in 6 of 31 patients.
Conclusion: In patients with pancreatic tumors, diffusion-weighted MR imaging
(DWI) performs significantly better in the detection of liver metastases than MDCT.
This is of particular relevance to therapeutic management.
B-134
14:27
MR imaging of focal liver lesions: Diffusion-weighted imaging versus
gadoxetate-enhanced MRI. Preliminary results
N. Bastati-Huber, W. Matzek, S. Baroud, C. Koelblinger, C.J. Herold, W. Schima,
A. Ba-Ssalamah; Vienna/AT (nina.bastati@meduniwien.ac.at)
Purpose: To compare diffusion-weighted imaging (DWI) with gadoxetate-enhanced
T1w 3D GRE MR imaging for focal liver lesion (FLL) detection and characterization
using consensus evaluation, histology and follow-up as reference standard.
Methods and Materials: Thirty-eight patients (21 men,17 women; mean age 69.2
years) with at least one FLL (mean size 21 mm) were examined at 3 Tesla Siemens
for FLL detection and characterization. DWI (b values 50, 400 and 800 sec/mm2)
and dynamic gadoxetate-enhanced 3D-GRE MRI in the arterial-, portal venous and
equilibrium phase as well as 20 min post-contrast in the hepatospecific phase were
performed. Reference standard for diagnosis was obtained from consensus review
by two observers of DW and dynamic contrast-enhanced images, pathologic data
and follow-up imaging results. Apparent diffusion coefficient (ADC) was measured
for FLLs identified at consensus review. DWI and gadoxetate-enhanced 3D GRE
images were compared.
Results: From a total of 92 FLLs (71 malignant, 21 benign), only 83 lesions could
be detected on gadoxetate-enhanced MR imaging (90%) and only 78 lesions
(85%) were detected on DWI at consensus review. The difference between both
sequences was not statistically significant (P 0.59). However, FLL characterization was significantly better for gadoxetate-enhanced T1w 3D GRE (94.8%) than
with DWI (71.8%, P 0.05). ADCs of malignant FLLs were significantly lower than
those of benign FLLs (P 0.05).
Conclusion: 3 Tesla MRI gadoxetate-enhanced T1w 3D GRE MR imaging is
slightly better than DWI for detection and significantly superior for the characterization of FLL.
B-135
14:36
Diffusion-weighted MR imaging of focal hepatic lesion on 3 T: Effect of
intravenous gadoxate disodium (Gd-EOB-DTPA)
J. Choi, M.-J. Kim, J. Lim, J.-Y. Choi, K. Kim; Seoul/KR (pipi927@yuhs.ac)
Purpose: To assess whether administration of gadoxate disodium (Gd-EOB-DTPA)
might affect lesion conspicuity and ADC values on diffusion weighted imaging (DWI)
for hepatic magnetic resonance imaging (MRI) on 3-T system.
Methods and Materials: Twenty patients with 29 focal hepatic lesions (hepatocellular carcinoma 18, metastasis 6, hemangioma 5) underwent DWI on 3-T system
before and after administration Gd-EOB-DTPA (0.025 mmol/kg). Non-breath hold
DWI was performed with b values of 200, 400 and 800 s/mm2. Signal-to-noise ratio
(SNR), contrast-to-noise ratio (CNR) of each lesion, and ADC values of the liver
and lesion were calculated for precontrast and postcontrast images. The differences
between precontrast and postcontrast data were assessed with paired t test.
Results: The CNRs and ADC values of focal hepatic lesions were not significantly
different before and after administration of contrast agent. Mean CNRs and ADC
values of focal hepatic lesions were (46.71 p 29.72 and 1.20 p 0.40, respectively)
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for precontrast and (45.69 p 29.66 and 1.23 p 0.35) for postcontrast images.
Mean SNRs and ADC values of the liver on precontrast images (19.34 p 7.59 and
1.23 p 0.15, respectively) were significantly lower (p 0.05) on postcontrast images
(15.65 p 6.78 and 1.16 p 0.14).
Conclusion: Postcontrast DWI after Gd-EOB-DTPA administration can be used
as a substitute for precontrast DWI on 3-T system.
B-136
14:45
Comparison of three methods for the construction of liver and spleen
apparent diffusion coefficient color parametric maps
T.G. Maris1, S. Gourtsoyianni1, K. Karolemeas2, N. Papanikolaou1, S.D. Yarmenitis1,
N. Gourtsoyiannis1; 1Iraklion/GR, 2Athens/GR (tmaris@med.uoc.gr)
Purpose: To compare three mathematical techniques for the calculation of apparent
diffusion coefficient (ADC) of normal liver, liver focal lesions and normal spleen.
Methods and Materials: Fifty consecutive patients underwent MRI examination of
the liver and spleen, utilizing a spin-echo echo planar imaging diffusion sequence
with four b-values (0, 50, 500, 1000). ADC calculated colour image maps were
post-proccessingly reconstructed using (a) a commercially available, (b) a standard
linear and (c) a weighted linear regression fitting model with b-values of 50, 500
and 1000. The three analytical methods (a, b, c) were compared in terms of their
precision in the ADC calculations.
Results: Differences amongst all ADC values were considered significant (ANOVA,
p 0.01) using either methods. Post-hoc pairwise comparisons showed a better
discrimination between normal liver and focal liver lesions when using method (c)
(p 0.01). ADC measurements were performed with method (c) that showed a better
precision (mean CV=3.6%) when compared with methods (a) and (b) (mean CV
= 8.5%). CV was considered stable throughout the whole range of ADC measurements when method (c) was used (CV discrepancy = 1.13 %). Bland-Altman plots
showed a 4% increment of the mean ADC values when method (c) was used and
a random statistical variation within the 95% confidence intervals indicating that
all three methods could be used interchangeably.
Conclusion: ADC quantification of the liver and spleen may be performed with
both linear and weighted regression analysis methods; however, the precision in
ADC measurements is significantly improved when weighted regression analysis
methods are utilized.
B-137
14:54
Hepatic transit time analysis using contrast-enhanced MRI: Comparison
of patients with liver metastases from colorectal cancer and healthy
volunteers
J. Hohmann1, C. Müller2, A. Oldenburg2, J. Skrok2, K.-J. Wolf2, T. Albrecht2;
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Basle/CH, 2Berlin/DE (jhohmann@uhbs.ch)
Purpose: During the evolution of liver metastases, the hepatic blood supply changes
in favour of the arterial fraction. HTT analysis may enable the detection of such
changes. The aim of this study was to evaluate if HTT analysis with MRI can reveal
differences between patients with liver metastases from colorectal cancer (patient
group) and healthy volunteers (control group).
Methods and Materials: A total of 20 patients (11 f, 9 m, mean age: 68 y) and 22
volunteers (9 f, 13 m, mean age: 50 y) were studied using a bolus test sequence
(T1-Turbo-FLASH, Siemens Magnetom Vision 1.5 T, frame rate: 1/s). After 15 s
baseline imaging, a bolus of 3.0 ml MultiHance (Bracco, Milano, Italy) followed by
a 10 ml saline flash was injected and postcontrast images were acquired over 85
s. HTT were calculated as differences of the arrival times of the abdominal aorta
(AA), hepatic artery (HA), portal vein (PV) and one hepatic vein (PV). Statistical
evaluation included comparison of both groups and evaluation of an age dependency in the control group.
Results: The patients showed significant shorter HTT values (HV-AA: 12.88 p 2.79
s versus 17.79 p 3.96 s, P = 0.02; HV-HA 10.85 p 3.06 s versus 15.71 p 3.75 s, P =
0.02) except for HV-PV HTT (6.80 p 1.40 s versus 9.23 p 3.35 s, P = 0.12). There
was no significant slope of the regression line in the control group (P 0.05).
Conclusion: MRI can show HTT differences due to changes in blood supply. No
age dependency was found in the control group. There seems a need for more
liver-specific contrast agents, which may result in longer and therefore more
stable HTT.
Scientific Sessions
B-138
15:03
Quantification of liver fat content: Comparison of triple-echo chemicalshift gradient-echo imaging and in vivo proton MR spectroscopy
B. Guiu, R. Loffroy, J.-M. Petit, S. Aho, D. Ben Salem, P. Hillon, J.-P. Cercueil,
D. Krausé; Dijon/FR (Bguiu@hotmail.fr)
B-139
15:12
MR quantitation of liver lipids after partial hepatectomy in a mouse model
at a clinical 3 T system
H. Ittrich, J. Heeren, J. Herkel, M. Merkel, K. Peldschus, A. Koops, U. Beisiegel,
G. Adam; Hamburg/DE (koops@uke.uni-hamburg.de)
Purpose: To compare different MR fat imaging sequences for a non-invasive in
vivo measurement of liver lipid accumulation after partial hepatectomy in different
mice models.
Methods and Materials: In vivo MRI was performed before 6h, and 24h after partial
hepatectomy (PH) in apolipoprotein E (ApoE) deficient and wildtype mice (WT,
control) using a clinical 3 T scanner with a small animal solenoid coil. Four different
T1w sequences were estimated: TSE, fat-saturated (fat-sat) TSE, water-saturated
(wat-sat) TSE, and an in- or opposed-phase (iop) FFE. SNR was measured in liver
at all time points corrected by standardized external control tubes filled with water
and oil using ImageJ (NIH). Liver lipid concentrations (LLC, µg/mg protein) were
measured at each time point after liver removal by standard laboratory methods.
Differences in liver fat content after PH between both animal groups were tested for
statistical significance (t test, p 0.05). Pearson's correlation coefficient (r) between
SNR and fat concentrations was calculated for all sequences.
Results: In vivo measurements showed time-dependent SNR changes in both
groups correlating to the LLC changes after PH. LLC showed an accelerated
increase in ApoE mice of 123.2 p 8.8% after 6 h and 240.0 p 25.8% after 24 h in
comparison to WT mice (6 h: 39.0 p 17.1%, 24 h: 166.2 p 16.8%). R between SNR
and LLC showed the best correlation for T1w wat-sat TSE (r=0.98), followed by iop
FFE (r=-0.95), fat-sat TSE (r=0.84), and normal T1w TSE (r=0.75).
Conclusion: Liver lipid concentrations and defects in liver lipid metabolism in
preclinical small animal models can be measured and detected by non-invasive
MRI at a clinical 3 T MR system.
B-140
15:21
Diagnosis of rejection after liver transplantation: Use of phosphorus-31
magnetic resonance spectroscopy (31P-MRS)
T. Jiang, S. Liu, X. Zheng; Shanghai/CN (laijiangtaotao@yahoo.com.cn)
Purpose: To delineate 31P-MRS abnormalities in patients with chronic rejection
and to characterize spectral changes by pathology.
Methods and Materials: 66 liver transplant recipients (18 with chronic rejection
and 48 with normal graft function) and 38 controls (23 healthy volunteers and fifteen
patients with biliary duct stricture) were studied with in vivo 31P-MRS.
Results: (a) The mean value of PME/B-ATP ratio of the rejection group was
1.15p0.07 and 95% confidence interval (CI) was 1.08-1.16 vs 0.84p0.09 and
0.81-0.87 of the normal liver trans-plantation group. According to the results of
ROC curve fitting, given the threshold 1.01, the diagnostic sensitivity was 100%,
14:00 - 15:30
Room B
Musculoskeletal
SS 310
Arthritis
Moderators:
A. Chevrot; Paris/FR
P. Peloschek; Vienna/AT
B-141
14:00
Phase-contrast radiography in a clinical setting, using a high-resolution
digital imaging system with a small-focus X-ray tube instead of
synchrotron radiation: Quantitative analysis of bone mass processed by
wavelet transformation for the earlier detection of rheumatoid arthritis
J. Tanaka, H. Oda, T. Mimura, C. Honda, H. Oohara, Y. Wada, H. Kawasaki,
A. Kondou, N. Funakoshi; Iruma-gun/JP (jtanaka@saitama-med.ac.jp)
Purpose: To establish a method for the quantitative evaluation of osteoporosis
in early-stage rheumatoid arthritis (RA) using phase-contrast radiographic (PCR)
technology instead of synchrotron radiation.
Methods and Materials: A new X-ray imaging system consisted of a tungstenanode X-ray tube with a 123-µm focal spot and a computed radiography (CR) system
with a spatial resolution of 43.75 µm. The distances between the focal spot and
object, and the object and CR plate were 0.65 and 0.49 meters, respectively. The
distance from the object to the CR plate creates an edge-enhancement effect due
to phase-shift of the X-ray after passing through the object, to give sharper X-ray
images, i.e., PCR technology.
PCR as well as conventional X-ray imaging were performed on the hands of 40
patients with stage 1 and 2 RA, and in 34 healthy volunteers. Raw image data of
hands in a fixed area were processed by wavelet transformation. Pixels in images
that exceeded a fixed threshold were counted as bone trabeculae, and the percentages of extracted pixels were considered area ratios (AR) to indicate bone mass.
Results: Average AR values were 27.3% for patients and 33.0% for volunteers
(p 0.05). The conventional X-ray system did not reveal this difference among
the same subjects.
Conclusion: A decrease in bone mass in patients with RA was detected quantitatively by PCR technology. This technique may be used for the early detection of
RA due to its high image-sharpness.
B-143
14:09
MRI assessment of hand involvement from the very early to established
rheumatoid arthritis
P.E. Kosta, P. Voulgari, A.G. Zikou, C. Tsampoulas, A. Drosos, M.I. Argyropoulou;
Ioannina/GR (parkosta@yahoo.gr)
Purpose: To detect differences in MRI findings of hand involvement in patients
with very early (disease duration 3 months), early ( 12 months) and established RA.
Methods and Materials: Fifty-seven patients fulfilling the American College of
Rheumatology (ACR) criteria for RA, 26 with very early (group 1), 18 with early
(group 2) and 13 with established disease (group 3) were enrolled in the study. MRI
using T1, fat-suppressed T2 and contrast-enhanced T1-weighted sequences were
performed in the dominant hand. Assessment of bone marrow edema, synovitis
and bone erosions was performed by volumetric analysis and by the Omeract RA
scoring system.
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Purpose: To validate a triple-echo gradient-echo sequence for measuring the fat
content of the liver, using 1H magnetic resonance spectroscopy (1H-MRS) as the
reference standard.
Methods and Materials: This prospective study was approved by the appropriate
ethics committee, and written informed consent was obtained from all patients. In
107 patients with type 2 diabetes (46 men; 61 women; mean age, 59 years), 3.0-T
single-voxel point-resolved 1H-MRS of the liver (segment VII) was performed to
calculate the liver fat fraction from the water (4.3 ppm) and methylene (1.3 ppm)
peaks, corrected for T1 and T2 decays. Liver fat fraction was also computed from
triple-echo (consecutive in-phase, opposed-phase and in-phase echo times)
breath-hold spoiled gradient-echo sequence (flip angle, 20°), by estimating T2*
and relative signal loss between in- and opposed-phase corrected for T2* decay.
Pearson’s correlation coefficient, Bland-Altman’s 95% limit of agreement and Lin’s
concordance coefficient were calculated.
Results: Mean fat fractions calculated from the triple-echo sequence and 1H-MRS
were 8.8% (range, 0.7-33.6) and 8.7% (range, 0.2-34.1), respectively. Mean T2*
time was 14.7 msec (range, 4.4-25.4). Pearson’s correlation coefficient was 0.987
(P 0.0001) and Lin’s concordance coefficient was 0.986 (P 0.0001).
Conclusion: A breath-hold triple-echo gradient-echo sequence with a low flip angle
and corrections for T2* decay is accurate for quantifying fat in segment seven of the
liver. Given its excellent correlation and concordance with 1H-MRS, this triple-echo
sequence could replace 1H-MRS in longitudinal studies.
specificity was 93.7%, the positive predictive value was 85.7%, and the negative
predictive value was 100%. The mean value of PDE/B-ATP ratio was 5.06p0.62,
and 95% CI was 4.75-5.37 in the rejection group vs. 3.21p0.49 and 3.07-3.35 in
the normal liver transplantation group. Given the threshold 4.17, the diagnostic accuracy was 100%, specificity was 97.9%, the positive predictive value was 94.7%,
and the negative predictive value was 100%. (b) The ratios of B-ATP/Pi decreased
in biliary duct stricture group, while they increased in chronic rejection group. There
were similar changes in the ratios of PME/Pi. (c) pH values increased in biliary duct
stricture group and chronic rejection group. (d) Histological specimens showed focal
loss of hepatocytes, degeneration, and hepatocytic atrophy.
Conclusion: 31P-MRS imaging is valuable in detecting the metabolism of the liver
after transplantation, and suggests that alterations in the phospholipid metabolism
may be a useful future direction of research.
Scientific Sessions
Results: Analysis of variance (ANOVA) followed by the Least Significant Difference
(LSD) test showed significant difference in edema and erosions between early and
established RA, p 0.05. No significant difference was found in synovitis.
Conclusion: Edema, erosions and synovitis are findings in very early RA. Significant
worsening of edema and erosions takes place during the first year of disease.
B-144
14:18
A simplified MRI score of one hand to monitor rheumatoid arthritis in daily
practice
C. Cyteval1, A. Miquel2, D. Hoa1, J.-P. Daures1, X. Mariette2, B. Combe1;
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Montpellier/FR, 2Le Kremlin-Bicêtre/FR (c-cyteval@chu-montpellier.fr)
Purpose: To develop an easy, reproductive and workable method for hand MRI
scoring of arthritis correlate with the referential OMERACT rheumatoid arthritis
magnetic resonance imaging score (RAMRIS).
Methods and Materials: Of the 813 patients from the ESPOIR cohort (a French multicentric cohort of adults with early arthritis), 43 underwent baseline MRI examinations.
A simplified score was defined by statistically identifying the data of high influence
in RAMRIS. Then its correlation with RAMRIS was test using the spearman method.
Last, intra and inter-observer reproducibility of the 2 scores were calculated.
Results: Only the right hand was analysed for the new score. Bone areas for the
study of erosions and oedema were reduced from 23 to 9 corresponding to the
most eroded bones found with RAMRIS. The scale for erosions was reduce to 5
grades, synovitis graded as absent, mild or important and oedema absent or present.
The simplified score was highly correlated with RAMRIS (r=0.88, 0.88 and 0.90,
respectively, for erosion, synovitis, and oedema). Intra-reader kappas were good to
excellent for RAMRIS and the simplified score for erosion (K=0.67, 0.85) synovitis
(K=0.81, 0.89) and oedema (K=0.94, 0.97). Inter-reader kappas were moderate
to good for RAMRIS (K= 0.58 to 0.74), while kappas were good to excellent using
the simplified score (K= 0.72 to 0.78) with high significant difference compared to
RAMRIS for erosion and oedema.
Conclusion: This reproductive simplified score could be helpful for the use of MRI
in daily practice to monitor joint damage in rheumatoid arthritis.
B-145
14:27
Only erosions - but not bone marrow edema or contrast-medium
enhancement - are specific features in pre-diagnosis MRI of ankylosing
spondylitis
M.C. Wick1, R.J. Weiss2, W. Jaschke1, A. Klauser1; 1Innsbruck/AT, 2Stockholm/SE
(marius.wick@i-med.ac.at)
Purpose: To determine the most relevant diagnostic radiological features in prediagnosis magnetic resonance imaging (MRI) of patients with ankylosing spondylitis
(AS) compared to patients with sacroiliac involvement of other rheumatic diseases
or unspecific degenerative cause.
Methods and Materials: We prospectively collected and systematically analyzed
laboratory values, clinical data and initial pre-diagnosis contrast-medium enhanced
MRIs of 179 patients (46 male/133 female) admitted to the Radiology Department
between 2003 and 2006 for evaluation of the cause of low back pain. Standardized
pre-diagnosis MRI sequences were semi-quantitatively assessed for statistical
comparisons.
Results: Of all the 179 patients, 27 (15.1%) were diagnosed with AS at a mean
(SD) of 21.6 (40.5) days after the initial pre-diagnosis MRI. The remainder had
sacroiliac involvement of other rheumatic diseases or HLA-B27-negative unspecific
spondylarthropathies. While joint space irregularities, bone marrow edema, cysts
and contrast-medium enhancement could inconsistently be found in MRIs of all
patients, only erosions were statistically significantly (P 0.01) associated with
radiological findings in patients who were later diagnosed with AS. The presence
and score of erosions statistically significantly (P 0.01) correlated with laboratory
values of inflammation.
Conclusion: Only erosions, but not bone marrow edema or contrast-medium
enhancement, are specific measurable radiological findings in the pre-diagnosis
MRI of patients with AS.
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B-146
14:36
Are flexion views by computed tomography useful to evaluate anterior
atlantoaxial subluxation in rheumatoid arthritis?
T. Söderman, A. Sundin; Uppsala/SE (tomas.soderman@radiol.uu.se)
Purpose: This study compared computed radiography (CR) with computed tomography (CT) for evaluation of anterior atlantoaxial subluxation (AAS) in patients with
rheumatoid arthritis (RA).
Methods and Materials: A total of 23 RA patients visiting the outpatient clinic of
orthopaedic surgery entered this prospective study. CT examination was performed
with the patients supine, with the head and neck in the neutral and flexed positions.
Two routine CR of the cervical spine were performed in the neutral and flexed
positions. The amplitude of AAS was defined by measuring the distance between
the posterior surface of the anterior arch of the atlas and the ventral surface of the
dens. Unstable AAS was considered to be present when the difference between
AAs in the flexed and neutral position was r2 mm.
Results: Diagnostic CT images of the neck in neutral position and flexion were
obtained in 23 patients. None reported major symptoms during imaging and none
of the examinations was interrupted. Neutral and flexion CRs were obtained in 21
patients. In 12 cases, the magnitude of AAS in flexion was greater in radiography
than in CT. In five patients, CT was not able to demonstrate unstable AAS detected
by radiography. In two patients, radiography was not able to demonstrate unstable
AAS detected by CT.
Conclusion: The magnitude of AAS is often smaller when measured by functional
CT than by functional radiography. Therefore, the result of functional CT alone
is not reliable. Functional radiographs are needed to show the magnitude of the
AAS instability.
B-147
14:45
The validity of the New York radiological grading criteria in diagnosing
sacroiliitis by CT
M. Geijer, G. Gadeholt Göthlin, J. Göthlin; Gothenburg/SE
(ecrabstracts@geijer.info)
Purpose: To validate the New York criteria grading in CT of the sacroiliac joints.
Methods and Materials: With the aid of the NY criteria, in 1,304 CT studies,
perform an assessment of inflammatory and degenerative changes as well as of
normal anatomic variants: joint space width and shape; erosions; distribution, type
and width of sclerosis; involvement of the joints in sacroiliitis.
Results: There was definite radiological sacroiliitis in 420 joints of 251 patients. Of
these, more than 2/3 of the joint was involved in 71.0% of the joints. Sclerosis in the
ilium was much more prevalent than sacral sclerosis. With increasing NY grade, iliac
sclerosis width and extent increased, transition from sclerosis to normal bone was
indistinct at a higher rate, and the structure of sclerosis was more inhomogeneous.
Erosions in the joint surfaces were localized predominantly on the iliac side.
Conclusion: Only multiple or large erosions seem to be a valid solitary diagnostic
sign. Solitary erosions need supplemental evidence from other inflammatory signs.
Inflammatory sclerosis may be distinguished from degenerative sclerosis and can
sometimes support early diagnosis. Joint space width, joint shape, bone mineral
content, or enthesopathy have no place in sacroiliitis diagnosis on CT. The NY
criteria are not ideal for use with CT. A practical classification of sacroiliitis on CT
is proposed with the grading: no disease, suspect disease, and definite disease.
B-148
14:54
Initial experience of dual energy CT for the detection of UA deposition in
patient with gout
W. Liu, H.D. Xue, Z.Y. Jin, H. Sun, X. Wang; Beijing/CN (lw.pumch@hotmail.com)
Purpose: To assess the potential of dual energy CT (DECT) for the detection of
uric acid (UA) deposits in the feet of patients with gout.
Methods and Materials: A total of 17 patients (male, mean age 50.9 years, range
29-85 years) with known gout and 10 healthy subjects (male, 28-82 years old, mean
age 47.8 years) were scanned on a dual source CT scanner (Definition, Siemens
Healthcare, Forchheim, Germany) from ankle to toe in dual energy (DECT) mode
(tube voltage 80 and 140 kV). Calculation was done with a ratio value of 1.25. Color
coding was used to display the localization of UA deposits in the patient cohort.
Results: With DECT,17/17, 8/17, 8/17, 5/17, 2/17 and 4/17 of patients with gout
were found to have UA deposits in the metatarsophalangeal joints, medial malleolus,
lateral malleolus, tarsal bones, phalanges of the toes and around the calcaneus,
respectively. In gouty patients, 44.1% (75 of 170) of metatarsophalangeal joints
were affected, though with no palpable tophus in most cases.UA deposits in the
first metatarsophalangeal joints were found in all gouty patients. No UA deposit
was found in healthy subjects.
Scientific Sessions
Conclusion: With DECT techniques, localization of UA deposits can be demonstrated in gouty patients. Further investigations need to be done for accuracy
evaluation.
15:03
Dual energy computed tomography: A promising new technique for
assessment of gout
S. Nicolaou, J. Grebenyuk, A. Eftekhari, S. Galea-Soler, C. Yong-Hing, W. Wan,
T. Orton, P. Munk; Vancouver, BC/CA
Purpose: The dual energy CT (DECT) application has been proven to accurately
confirm uric acid deposition within kidneys. The authors of this pilot study worked
to expand this application to allow visualization of monosodium urate (MSU)
crystal deposition in gout arthropathy. It is vital for clinicians to differentiate gout
from other inflammatory arthropathies such that specific and timely treatment can
be provided.
Methods and Materials: This study was approved by the institutional review board.
Retrospective analysis of 13 patients with aspiration-proven gout (11 males, 2
females; mean age 61.2 years) and 10 control subjects with no history of gout who
underwent DECT evaluation of hands/wrists, elbows, knees and feet/ankles was
performed. Images were reviewed independently by two DECT-trained radiologists.
A rheumatologic assessment of subjects with aspiration-proven gout and a complete
chart review of all study participants were performed.
Results: DECT was more accurate in identifying the degree of disease burden in
gout. The number of MSU crystal deposition sites found in patients was four times
higher in DECT (200) than by clinical assessment (53) (P = 0.002). DECT was
significantly better at identifying disease in the hand/wrist, knees and feet/ankles
(P 0.015). Subclinical sites, such as deep ligaments and tendons not previously
described in literature, were also appreciated on DECT.
Conclusion: Our study suggests that DECT is highly accurate in diagnosing gout
and delineating the extent of subclinical disease. DECT has further potential to be
used as a tool to monitor the response to urate-lowering therapy in tophaceous
gout.
B-150
15:12
Vertebral fractures in patients with ankylosing spondylitis: A retrospective
analysis of 66 patients
S. Sterl, J. Altenbernd, S.P. Lemburg, S.A. Peters, V. Nicolas, C.M. Heyer;
Bochum/DE (christoph.heyer@rub.de)
Purpose: Retrospective analysis of vertebral fractures in patients with ankylosing
spondylitis (AS) for evaluation of associations with mortality, concurrent neurological
deficits, and other complications.
Methods and Materials: Image analysis (conventional radiographs, CT, MRI) was
applied to all patients with AS admitted between 1997 and 2007 due to vertebral
fractures pertaining to fracture localisation and classification. Patient characteristics, trauma mechanism, neurological symptoms, and other complications were
documented.
Results: 66 patients (58% male, age 64p11 years) were enrolled in the study.
74% of patients suffered from minor trauma. 51 and 56% had cervicothoracic and
thoracolumbar fractures, respectively, while 8% had multi-level fractures. 63% of
patients suffered combined vertebrodiscal fractures. 70% revealed neurological
symptoms, significantly correlating with spinal stenosis (p=.024; Odds Ratio 4.265)
and hyperlordosis (p=.014; OR 4.806). 68% developed complications with noncombined fractures (p=.042; OR 4.954) and paravertebral hematomas (p=.009;
OR 16.969) representing independent risk factors. Female gender (p=.005; OR
15.617) and conservative therapy (p=.040; OR.094) exerted significant influence
on the mortality rate.
Conclusion: Vertebral fractures frequently occur in patients with AS after minor
trauma and often lead to neurological symptoms, which in turn are associated with
spinal stenosis and hyperlordosis. Paravertebral hematomas and non-combined
fractures are accompanied by higher incidences of other complications. Female
gender entails higher mortality.
Room C
GI Tract
SS 301b
Friday
B-149
14:00 - 15:30
CT colonography
Moderators:
S. Agostini; Marseille/FR
T. Mang; Vienna/AT
B-151
14:00
Full-laxative versus minimum-laxative CT colonography: Prospective
comparison of diagnostic performance
K. Nagata1, T. Oikawa2, S. Kudo3, H. Yoshida1; 1Boston, MA/US, 2Tokyo/JP,
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Yokohama/JP (Yoshida.Hiro@mgh.harvard.edu)
Purpose: To prospectively compare the full-laxative fecal-tagging virtual colonoscopy (VC) with minimum-laxative fecal-tagging VC in the detection of polyps with
64-detector computed tomography (CT).
Methods and Materials: One-hundred and one patients with high risk for developing
colorectal cancer were alternately allocated to either a full-laxative fecal-tagging
group (n = 51) or a minimum-laxative fecal-tagging group (n = 50) before undergoing
VC. The full-laxative regimen consisted of the administration of 2 L of polyethylene
glycol solution with 20 mL of Gastrografin for fecal tagging. The minimum-laxative
regimen consisted of the ingestion of 45 mL Gastrografin over 3 days and 10 mL
of sodium picosulfate solution the night before the CT scanning. We assessed the
accuracy of polyp detection in each preparation group using optical colonoscopy
as the reference standard.
Results: In the full-laxative fecal-tagging group, per-patient sensitivity, specificity,
and positive and negative predictive values for polyps r6 mm were 97, 92, 88,
and 98%, respectively, while those of the minimum-laxative fecal-tagging group
were 88, 68, 56, and 92%, respectively. There was no statistically significant difference in the sensitivities (p 0.05), whereas the specificities were statistically
significantly different (p 0.05). For polyps r10 mm, sensitivity was 100% in both
the full-laxative fecal-tagging (15/15 polyps) and minimum-laxative fecal-tagging
(9/9 polyps) groups.
Conclusion: Full-laxative and minimum-laxative fecal-tagging VC yielded an equally
high sensitivity in the detection of polyps r6 mm; thus, both can be options for all
patients who undergo colorectal cancer screening.
B-152
14:09
Virtual tagging for better laxative-free CT colonography
J. Näppi1, H. Yoshida1, M.E. Zalis1, S. Gryspeerdt2, P. Lefere2; 1Boston, MA/US,
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Roeselare/BE (jnappi@partners.org)
Purpose: To assess the potential of virtual tagging (VTG) in improving the detection
accuracy of laxative-free CT colonography (CTC).
Methods and Materials: Forty-six patients were prepared for 1-2 days prior to CTC
in two institutions by dietary tagging with barium (from 12.5 mL with 40% to 250 mL
with 2.1% w/v concentrations) or non-ionic iodine (10 mL diluted in 150 mL of
beverages). No bowel cleansing or laxatives were used. The CTC was performed
in supine and prone positions by 3 CT scanners with 1.0-2.5 mm collimations,
0.7-2.5 mm reconstruction intervals, 28-110 mA currents, and 120-140 kVp voltages. The findings of post-CTC colonoscopy were correlated with the CTC data.
A fully automated VTG method was used to highlight poorly tagged materials and
partial-volume artifacts. A previously validated fully automated scheme was used
to detect polyps without and with the VTG. The detection accuracy was evaluated
by use of the jack-knife free-response receiver operating characteristic test. The
sources of false positives (FPs) were identified.
Results: All cases were tested regardless of diagnostic quality. There were 10
adenomas: 6 were 6-9 mm and 4 were 10 mm. The accuracy of automated
detection with (without) VTG was 90% at 2.7 FPs (70% at 2.4 FPs) per scan for
adenomas 6 mm. The improvement by VTG was statistically significant (p 0.05).
With VTG, the leading sources of FPs were completely untagged feces (55%) and
thickened folds (10%).
Conclusion: The application of VTG can yield significant improvement in the accuracy of polyp detection in laxative-free CTC.
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B-153
14:18
Electronic cleansing for CT colonography: Does it help the performance of
computer-aided detection software in a high-risk population for colorectal
cancer?
J. Wi, S. Kim, J. Lee, J. Lee, J. Han, B. Choi, S. Kim; Seoul/KR (jywi@radiol.snu.ac.kr)
Purpose: To compare the performance of computer-aided detection (CAD) software
for CT colonography (CTC) with and without the use of electronic cleansing (EC)
in a high-risk population for colorectal cancer tagged with robust fecal tagging
(FT) protocol.
Methods and Materials: A total of 32 patients suspected of having colonic polyps
underwent CTC followed by a same-day optical colonoscopy (OC). All patients
underwent a dry preparation using magnesium citrate and FT with 24-28 g barium
and 50 ml of gastrografin. Each CTC data set was processed with colon CAD
(Philips) with and without the use of EC. Per-polyp sensitivity was calculated using colonoscopy as a reference standard. The average number and cause of false
positives (FPs) were also analyzed.
Results: A total of 86 polyps (54 polyps, 6 mm; 16, 6-9 mm; 16, r10 mm) were
detected in 29 of 32 patients by OC. Per-polyp sensitivities of the data sets with
and without EC were 93.8 and 84.4% for polyps r6 mm and 100 and 87.5% for
polyps r10 mm, respectively. Per-polyp sensitivities were not significantly different
between the two data sets. The average number of FPs with EC was 6.3, which
was significantly larger than that (3.1) without EC (P 0.0001). The most common cause of FPs was ileocecal valve in both data sets (29.7% with EC, 32.1%
without EC). However, untagged feces was a significantly less common cause of
FPs (5.9% with EC, 11.6% without EC) with EC, EC-related artifacts being more
common (28.7% with EC, 0% without EC; P 0.05).
Conclusion: Comparable per-polyp sensitivity can be achieved when CTC CAD is
used with EC as compared to without EC. However, the significantly larger number
of FPs with EC remains to be improved.
B-154
14:27
CT colonography: Computer-assisted detection (CAD) of colorectal cancer
in 132 patients
C. Robinson1, G. Iinuma2, W. Topping1, S. Punwani1, S.A. Taylor1, L. Honeyfield1,
S. Halligan1; 1London/UK, 2Tokyo/JP (charlotterobinson@mac.com)
Purpose:CT colonography (CTC) is well established for polyp detection in colorectal cancer screening. Detection of polyps has recently been enhanced by the
introduction of computer-assisted detection (CAD). However, the potential for CAD
detection of established cancer in symptomatic patients has attracted less attention.
Large case series are especially needed in this context, especially since most CAD
algorithms have not been developed with cancer in mind.
Methods and Materials: A total of 132 symptomatic patients with proven colorectal
cancer were recruited from 6 centres. Multi-detector CTC colonography had been
performed in each using a standard technique, but with variable bowel preparation.
DICOM data was uploaded to a PC workstation and a proprietary CAD algorithm
(Medicsight ColonCAD 3.1) applied to all data sets. A single observer interrogated
each CTC, classifying individual CAD prompts as either true-positive if related to
a cancer or false-positive if elsewhere (including those on polyps). Colonoscopic
data were used to aid matching.
Results: Of the 132 cancers, 119 (90.2%), 117 (88.6%), 115 (87.1%) and 98
(74.2%) were detected at filter settings of 0, 50, 75 and 100, respectively. Of those
cancers detected, 42.9, 41.9, 47.8 and 54.1% were only prompted by CAD on either
the prone or supine acquisition at filter settings of 0, 50, 75 and 100, respectively.
False-positive prompts decreased with increasing filter value (median 65, 57, 45
and 24 per patient at values of 0, 50, 75 and 100, respectively), but many data
sets were poorly prepped.
Conclusion:CAD is sensitive for the detection of symptomatic colorectal cancer,
but must be applied to both prone and supine data sets.
B-155
14:36
Influence of a CAR software on different experienced readers: Primary 3D
fly-through approach versus 3D + CAR approach
M. Rengo, R. Ferrari, F. Vecchietti, D. Bellini, D. Caruso, P. Paolantonio, A. Laghi;
Latina/IT (ferraririccardo@gmail.com)
Purpose: To compare the performances of different experienced readers using a
primary 3D fly-through approach with and without the use of a CAR analysis.
Methods and Materials: Three readers evaluated 50 patients with 100 endoscopically proven polyps (ranging from 3 to 40 mm) and different colonic preparations
(18 fluid tagging, 32 full cathartic preparation). Data set analysis was performed on
a VIATRONIX workstation equipped with V3D colon (version 1.3) software and with
Medicsight Colon CAR 1.3 software. Per-polyp sensitivity, inter-reader agreement,
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mean reporting time and false positive were evaluated for each approach.
Results: Less experienced readers had increased per-polyp sensitivity respectively
from 75 and 61% for 3D analysis to 86 and 74% for primary 3D + CAR analysis
with a significant difference (P = 0.001 and P = 0.01), while no significant differences were found for the expert ones (P = 0.06). Less experienced readers were
faster when assisted by CAR, but no significant differences were found in the
mean reading time of all readers (P = 0.5/0.07/0.1). Mean false-positive findings
for CAR analysis were 12 (SD 13). There was a decrease in the false positive for
all readers when assisted by CAR, especially for the less experienced ones. Interreader agreement was higher among all readers when assisted by CAR (0.33 to
0.63/0.39 to 0.62/0.58 to 0.65)
Conclusion: Our study demonstrated that less experienced readers, if assisted
by CAR, can significantly increase their sensitivity. They have other not significant
advantages like the reduction in the false-positive rate and mean reporting time.
B-156
14:45
CT colonography polyp matching: Differences between experienced
readers
M.H. Liedenbaum, A.H. de Vries, P.M.M. Bossuyt, E. Dekker, J. Stoker;
Amsterdam/NL (M.H.Liedenbaum@amc.uva.nl)
Purpose: To investigate if experienced readers differ in the matching of CT
colonography (CTC) and optical colonoscopy (OC) polyp cases and to explore the
reasons for these differences.
Methods and Materials: A total of 28 pre-selected CTC-OC matching cases were
presented to eight experienced CTC readers. The cases represented a broad
spectrum of findings, not completely fulfilling the often-used matching criteria: CTC
and OC polyp within 50% size range, similar morphology, location in the same
or adjacent colonic segment. Matching was performed using CTC examinations,
videotaped OCs and OC reports. In 21 cases, one OC and CTC polyp were shown
(single polyp cases). In seven cases, multiple polyps per case had to be matched
(38 CTC polyps and 44 OC polyps).
Results: The number of matches per reader varied from 13 to 19 in single polyp
cases. Almost complete matching agreement was observed in 15 cases: seven or
eight readers indicated a match. Low agreement was found in the remaining six
cases: only four or five readers indicated a match. In five of these six cases, a large
size difference ( 50%) existed between the CTC and OC polyp. In the multiple
polyp cases, matching varied from 27 to 35 CTC polyps; 9-11 matches for polyps
r10 mm, 8-11 for polyps 6-9 mm and 7-14 for polyps 6 mm.
Conclusion: Experienced CTC readers agree to a considerable extent in the matching of selected cases, but non-negligible differences in matching exist. Our proposal
is to consider consensus matching for difficult cases. This study was performed in
collaboration with the International CTC Matching Group.
B-157
14:54
Defining the optimal operating point for colon computer-aided detection
in clinical practice: Influence of CAD-generated false positives on reader
performance and diagnostic confidence for CT colonography
S.A. Taylor1, J. Brittenden2, J. Lenton3, H. Lambie3, A. Goldstone3, P. Wylie4,
D. Tolan3, D. Burling4, S. Halligan1; 1London/UK, 2Wakefield/UK, 3Leeds/UK,
4
Harrow/UK (csytaylor@yahoo.co.uk)
Purpose: The optimum operating point for computer-aided-detection (CAD) software in CT colonongraphy (CTC) is poorly defined. The purpose was to investigate
whether increasing numbers of false positive (FP) CAD prompts are detrimental to
reader sensitivity and diagnostic confidence for non-expert readers.
Methods and Materials: A total of 50 CTC data sets (male 29, mean age 65 years;
25 containing 35 polyps r 5 mm) were selected where CAD had 100% polyp sensitivity at each of the two sphericity settings (0 and 75), but differed greatly in FP
number. Data sets were read by five trained readers twice, once at each sphericity,
at an interval of 6 weeks. Findings, report time and confidence pre and post secondread CAD were noted. Sensitivity, specificity, reading times and confidence were
compared using the paired exact test and t test, respectively. Receivers operating
characteristic curves were generated based on case classification.
Results: CAD generated a mean 15 and 42 FP at sphericity 75 and 0, respectively. CAD at both settings increased per patient sensitivity (from 82 to 87%, P =
0.03), and per polyp sensitivity (by 8 and 10% for sphericity 0 and 75, respectively,
P 0.001), although specificity decreased (84-79%). There was no difference in
reader sensitivity, specificity or confidence between CAD sphericity settings (P =
1.0, 1.0, 0.11, respectively). AUC was 0.78 [95% CI 0.70-0.86] and 0.77 [95% CI
0.68-0.85] for sphericity 0 and 75, respectively. CAD added median 4.4 (IQR 2.7-6.5)
and 2.2 minutes (IQR 1.2-4.0) for sphericity 0 and 75, respectively (P 0.001).
Conclusion: Larger numbers of false positives do not negate the beneficial effect
of CAD on reader sensitivity or confidence, but reduce efficiency.
Scientific Sessions
B-158
15:03
Colonic flat lesions detection using 64-MDCT colonography and a CAD
system: Preliminary results
F. Iafrate, A. Stagnitti, A. Pichi, R. Ferrari, D. Caruso, F. Vecchietti, A. Laghi;
Rome/IT (francoiafrate@gmail.com)
B-159
15:12
Using CT colonography as a triage technique after a positive faecal occult
blood test in colorectal cancer screening
M.H. Liedenbaum1, A.F. van Rijn1, A.H. de Vries1, H.M. Dekker2, M. Thomeer3,
P. Fockens1, P.M.M. Bossuyt1, E. Dekker1, J. Stoker1; 1Amsterdam/NL,
2
Nijmegen/NL, 3Rotterdam/NL (M.H.Liedenbaum@amc.uva.nl)
Purpose: To determine whether CT colonography (CTC) is an effective triage
technique in faecal occult blood test (FOBT) positives.
Methods and Materials: Consecutive guiac (G-FOBT) and immunochemical (IFOBT) FOBT positive screening participants scheduled for colonoscopy underwent
CTC with iodine tagging bowel preparation in three different institutions. Each CTC
was read by two independent, experienced observers. Per-patient positive and
negative predictive values (PPV and NPV) were calculated based on double reading
with a 10 mm CTC cut-off lesion size (polyp or carcinoma) and comparison with
segmental unblinded colonoscopy. Patient acceptance was evaluated with questionnaires. The costs of initial clinical management were calculated for a strategy with
CTC triage and a strategy without triage before colonoscopy.
Results: A total of 302 FOBT positives were included (54 g-FOBT and 248 I-FOBT).
Of all, 22 FOBT positives (7%) had a colorectal carcinoma, 142 (47%) had a lesion
r10 mm and 210 (70%) had a lesion r6 mm. The participants considered colonoscopy to be significantly more burdensome than CTC. The per patient PPV of CTC
for the detection of colonoscopy lesions r10 mm was 84% (95% CI: 77-91%; 90%
for g-FOBT positives and 82% for I-FOBT positives); the NPV was 84% (95% CI:
77-91%; 83 and 84%, respectively). Costs with CTC as triage technique were 17%
higher compared to performing direct colonoscopy in all FOBT positives.
Conclusion: CTC with limited bowel preparation has reasonable predictive values
in an FOBT-positive population, but due to the high prevalence of clinically relevant
polyps in FOBT positives, the total costs will increase if CTC is used as a triage
technique.
B-160
15:21
CT colonography: C-RADS 2 - which is the patient’s preferred follow-up
colon test and interval?
F. Turini, E. Neri, F. Cerri, P. Vagli, M. Barattini, C. Bartolozzi; Pisa/IT
(f.turini@med.unipi.it)
Purpose: According to the CT Colonography (CTC) Reporting and Data System (CRADS), the category 2 is the presence of 3 medium sized polyps. In these patients
a follow-up at 3 years, is reasonable, taking into account age, sex, comorbidities,
patient's preference. The aim of this study was to evaluate the patient's preferred
follow-up colon test and the time interval in case of C-RADS 2.
Methods and Materials: We retrospectively reviewed the data of 673 patients
who underwent CTC between 2005 and 2008. A total of 445 patients were negative at CTC (C-RADS 1; 66%), 133 were found to have 3 medium size polyps
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Room F1
Genitourinary
SS 307
Kidney: Morphological and functional studies
Moderators:
G. Manenti; Rome/IT
C. Roy; Strasbourg/FR
B-161
14:00
The extrinsic ureteropelvic junction obstruction caused by “anomalous”
crossing vessels: Does it exist?
J. Petersen, P. Rehder, K. Rapf, B. Glodny; Innsbruck/AT
(johannes.petersen@i-med.ac.at)
Purpose: To investigate whether or not “anomalous” crossing vessels (CVs) may
have an influence on the drainage and width of the renal pelvis and ureters.
Methods and Materials: 1043 subsequent patients were enrolled into the study.
0.625 mm collimated 64-slice-MDCTs with different phases, including an arterial
phase, have been assessed by two observers in consensus.
Results: 2077 kidneys were supplied by 2656 arteries and 2411 veins. The width
of the kidney pelvis was 8.8p4.4 mm on the right, and 8.6p6 mm on the left side. On
the right side, in 12% of the patients at least one "additional" artery was crossing
the renal pelvis or ureters anteriorly, posteriorly (5.7%), anteriorly and posteriorly
(1.1%); in 8.6% at least 1 vein was crossing anteriorly, posteriorly (11.1%), anteriorly
and posteriorly (2.3%). On the left side, in 11.8%, an artery was crossing anteriorly, posteriorly (6.1%), and anteriorly and posteriorly (1.5%); in 1.5%, a vein was
crossing posteriorly, and in 0.2% anteriorly. Variance analyses did not reveal any
relations between CVs and the width of the renal pelvis or ureter. CVs did not have
any effects with respect to hydronephrosis either, as shown by multiple regression
analysis models. Gender, position and size of the kidneys show moderate positive
correlation with the width of the urinary tract (p 0.0001).
Conclusion: In this large cohort of unselected patients, “anomalous” crossing
vessels did not reveal any verifiable effects on the upper urinary tract. Therefore,
we disbelieve the existence of the so called “extrinsic urteropelvic junction obstruction” caused by CVs.
B-162
14:09
Feasibility study of blood oxygenation level-dependent MRI in chronic
kidney disease
X. Xu, H. Ling, W. Chai, K. Chen, W. Fang; Shanghai/CN
(xuxueqin1212@yahoo.com.cn)
Purpose: To evaluate feasibility of blood oxygenation level-dependent (BOLD)
MR imaging in assessment of renal functions in patients with chronic kidney
disease (CKD).
Methods and Materials: 57 patients with CKD and 70 healthy volunteers underwent
BOLD MR imaging of the kidneys. The patients were classified into 5 stages according to the K/DOQI CKD (kidney disease outcome quality initiative). R2* of the
cortical and medullar of the kidneys were calculated and compared. Reproducibility
was assessed by repeating the same protocol in 10 randomly selected volunteers
after 1-6 months. The R2* were compared between patients and volunteers ageand sex-matched. The R2*of patients were compared among different stages.
For statistical analysis, Student t tests, ANOVA, Pearson’s correlation tests and
Spearman’s correlation tests were used.
Results: In all volunteers, medullary R2* were higher than cortical R2* (18.14/
secp2.51, 12.63/secp1.40). No statistically significant difference was found in the
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Purpose: To evaluate the ability of CAD software to detect morphologically flat
lesions at CT colonography.
Methods and Materials: The CTC datasets of 31 patients with 34 endoscopically
proven flat lesions were loaded onto a workstation equipped with CTC viewing
software and reviewed with and without CAD by two radiologists experienced in
CTC interpretation fully aware of the colonoscopic report. A total of 28 patients
underwent fecal tagging preparation before CTC and remaining 3 patients underwent full cathartic prep.
Results: Eight of 34 lesions were missed by reading CTC examination using 2D
as primary approach and 3D as problem solving without CAD. CAD detected 32 of
34 flat lesions. Two radiologist in consensus using CAD software detected 30 of 34
lesions and two lesions detected by CAD was not reported as flat lesions due to
low conspicuity. Nineteen lesions were of 3 mm in height, and 11 ranging in height
between 1 and 2 mm. Two lesions with the height of 1 mm or less were not seen on
CT Colonography. Six lesions located on the haustral fold showed higher conspicuity
on the 3D endoluminal view than on the colon window setting 2D view.
Conclusion: In conclusion, 25% of flat lesion in our population was missed by
radiologists without CAD that improved flat lesion detection from 75 to 90% of
proven lesions. Visualized flat lesions were 3 mm or lower in height and 6 mm or
greater in diameter. Lesions with a height of 1 mm or less were not seen on CT
colonography.
(C-RADS 2; 20%) and 95 had r3 medium size polyp or larger lesions (C-RADS 3
and 4; 14%). In all C1 cases a 5-year follow-up was suggested; in C2 a 1-3 years
follow-up by means of CTC or colonoscopy. C3 and C4 were immediately referred
to colonscopy. We estimated the number of C-RADS 2 patients followed-up with
CTC or colonoscopy and the patient's preferred follow-up time interval.
Results: Data collected in a 3-year follow-up showed 64/133 (48%) patients who
accepted a follow-up and choosen CTC to repeat the colon test, with a maximum
of 18 months follow-up. Sixty-nine out of 133 (52%) underwent colonoscopy. Among
these 18 (13%) preferred to undergo immediate colonoscopy and 51 (38%) accepted a maximum of 18 months follow-up.
Conclusion: The majority of patients classified as C-RADS 2 prefer to repeat
the colon test by means of CTC, but all patients accept a maximum of 18 months
follow-up, even when 3 years are proposed.
Scientific Sessions
repeat study of the volunteers (P 0.05). Patients with CKD had significantly lower
renal medullary R2* (t=-4.383, P =0.000) than did volunteers (16.35/secp2.72
vs. 18.14/secp2.67). The medullary R2* were lower in CKD1, CKD4 and CKD5
patients than volunteers (P 0.05). There was an appositive correlation between
the medullary R2* and sCr level (r=-0.250, P=0.011) in the patients.
Conclusion: BOLD MR imaging is feasible and reproducible in the assessment of
renal function, especially in the detection of early stage renal failure of CKD.
B-163
14:18
Diffusion-weighted MR imaging of kidneys in healthy volunteers and
patients with chronic kidney disease: Initial study
X. Xu, W. Fang, K. Chen, H. Ling, W. Chai; Shanghai/CN
(xuxueqin1212@yahoo.com.cn)
Purpose: To prospectively evaluate reproducibility of diffusion-weighted MR imaging
in assessment of renal functions in healthy volunteers and feasibility to differentiate
the renal functions of patients with chronic kidney disease (CKD).
Methods and Materials: Seventy-two healthy volunteers and 43 patients underwent
DW MR imaging of the kidneys with a single breath-hold. The patients were classified into 5 stages according to the K/DOQI CKD. Apparent diffusion coefficients
(ADC) value of the kidneys was calculated with b 500 sec/mm2. Reproducibility
was assessed by repeating the same protocol in 10 randomly selected volunteers
after 1-6 months. The ADC values were compared between patients and healthy
volunteers age- and sex-matched. The ADCs of patients were compared among
different stages. For statistical analysis, Student t tests, ANOVA, Pearson’s correlation tests and Spearman’s correlation tests were used.
Results: In all volunteers, difference between the cortex and medulla could not
be observed in DW images. No statistically significant difference was found in the
repeat study of the volunteers (P 0.05). Patients with CKD had significantly lower
renal ADC (t=-4.383, P =0.000) than did volunteers. A liner correlation was found
between the renal ADCs and stages of CKD (r=-0.492, P=0.000). There was an
appositive correlation between the ADCs and sCr level (r=-0.374, P=0.000) in the
patients. Compared with the volunteers, the lower ADCs was only found in the
patients with sCr level higher (P 0.05).
Conclusion: DW MR imaging is feasible and reproducible in the assessment of
renal function, especially in the detection of early stage renal failure of CKD.
B-164
14:27
MR diffusion-weighted imaging with apparent diffusion coefficient value in
renal insufficiency at 3 T
C. Roy, G. Bierry, A. Matau, M. Jeung, H. Lang; Strasbourg/FR
(Guillaume.Bierry@chru-strasbourg.fr)
Purpose: To investigate the relationship between apparent diffusion coefficient
(ADC) values measured by MR diffusion-weighted imaging (DW-MRI) in cases of
renal insufficiency (RI).
Methods and Materials: A total of 200 patients with various pathologies including 120
patients with moderate (GFR 40 mL· min) or severe (GFR 40 mL· min) RI were
explored at 3 T (Achieva, Philips) with axial DWI SE-EPI (TR/TE : 5,546/53 ms, 5 mm, b
value 0 and 1,000 s/mm2). They were divided into “control 50 pts”, “normal unique kidney
30 pts” and four groups of 30 pts: “moderate RI unique kidney”, “severe RI unique kidney“,
“moderate RI both kidney “, “ severe RI both kidney “. ADC was measured at 150 mm2
ROI by two experienced radiologists, as well as images analysis performed. Statistical
analysis was performed using SPSS software. ADC mean values and standard deviation
of each group were calculated and compared using Student’s t-test.
Results: Mean ADCs in control and normal unique kidney groups were both 1.9 x
10-3 mm2/ s. Mean ADCs of the four groups were as follows: 1.87 p 0.11, 1.82 p 0.17,
1.91 p 0.11 and 1.86 p 0.11 x 10-3 mm2/s, respectively. There was no statistically
significant difference in renal ADCs among the four groups of RI and control group.
On DWImages signal intensity was homogeneous for all types.
Conclusion: The ADCs were no significantly different in impaired kidneys and
normal functional kidneys. There was no correlation between the ADCs and GFR.
DW-MRI of the kidney does not seem to be a reliable method to differentiate normal
renal parenchyma and different renal diseases.
B-165
14:36
MRI-based functional evaluation of the kidneys in patients with renal artery
stenosis: Renal perfusion and blood flow analysis and their correlation
with biochemical markers
V. Zampa, S. Ortori, L. Faggioni, E. Guidi, V. Positano, S. Pinto, C. Bartolozzi;
Pisa/IT (virnazampa@hotmail.com)
Purpose: To evaluate the usefulness of MRI-based perfusion and renal blood
flow (RBF) analysis for renal function assessment in patients with suspected
renovascular hypertension.
Methods and Materials: Thirty-four patients (M:F=14:20, age 17-80 years, mean
58 years) with arterial hypertension underwent MRI of the upper abdomen on a
GE Signa Excite HDx 1.5 T scanner. Perfusion-weighted imaging was performed
running a free-breath multiphase T1-weighted fast-spoiled gradient-echo LAVA
sequence starting after intravenous administration of a 3-ml bolus of Gd-BOPTA
injected at 3 ml/s. Flow data were acquired through a 2D ECG-gated phase-contrast
sequence centered perpendicularly to the course of each renal artery, eventually
distal to stenosis site. Perfusion and flow analysis were carried out using homemade
software (HippoKidney vers. 1.0, IFC-CNR, Pisa) and a dedicated plug-in (CV Flow
4, GE Medical Systems), respectively.
Results: In kidneys with renal artery stenosis (RAS) compared with non-stenotic
ones, RBF was significantly decreased (p=0.0104, Mann-Whitney test), timeto-peak (TTP) and mean transit time (MTT) were longer (p=0.0094, p=0.0009),
while maximum upslope (MUS) and maximum signal intensity (MSI) were reduced
(p=0.0281, p=0.04). In kidneys with RAS, both glomerular filtration rate (GFR) and
serum creatinine levels correlated significantly with MTT, MUS, and MSI (rs=-0.4284/
p=0.04 and rs=0.5896/p=0.0039; rs=0.4838/p=0.0226 and rs=-0.6857/p=0.0004;
rs=0.5001/p=0.0179 and rs=-0.6897/p=0.004, Spearman rank test), and a significant
correlation was also detected between GFR and RBF (rs=0.4457/p=0.0429).
Conclusion: Perfusion and blood flow analysis of the kidneys can provide information about renal function and could be incorporated in a routine MRI protocol for the
assessment of patients with suspected renovascular hypertension.
B-166
14:45
Drug-induced MR-pyelography in the evaluation of non-excreting kidneys
M. Di Girolamo, G. Scavone, G. Argentieri, V. Vitale, L. Greco, V. David; Rome/IT
(digirolamomarco@hotmail.com)
Purpose: To evaluate the accuracy of this technique in the visualization of nonexcreting-kidneys.
Methods and Materials: 25 patients with non-excreting kidneys underwent druginduced MR-pyelography. 23 patients had undergone intravenous urography in
the 10 days preceding MRI while 2 patients had undergone contrast-enhanced
excretory MR-urography the day before. The examination was performed with a
3-D non-breath holding fat-suppressed Turbo SE sequence on coronal planes. To
obtain maximum filling of both the collecting system, the diuresis was pharmacologically induced by administering saline solution together with furosemide. Two
MR acquisitions were performed 5 and 10 minutes after diuresis induction. All the
patients underwent abdominal plain radiograph and urinary cytology. Retrograde
pyelography was performed twice at the beginning of the experience.
Results: In 24 patients, non-excreting kidney was related to obstructive uropathy
and in these cases drug-induced MR-pyelography allowed to detect the site of obstruction. Using conventional MR images, abdominal plain radiograph and urinary
citology, the cause of the obstruction was always determined (8 renal collecting
system tumors, 5 ureteral calculi, 3 retroperitoneal fibrosis, 1 ureteral obstruction
due to lumbar lymphadenopathy and 7 uretero-pelvic junction syndromes). In one
case, non-functioning kidney was due to renal tuberculosis.
Conclusion: Drug-induced MR-pyelography allowed a morphological study of renal
collecting system in patients with of non-excreting kidneys, avoiding the need to perform invasive retrograde pyelography, and could be considered the best diagnostic
imaging modality to perform after US, especially in case of ureteral obstruction.
B-167
14:54
Calculation of renal function by dynamic volume CT: Comparison with
scintigraphy in renal donors
C. Kloeters, S. Kandel, H. Meyer, L. Liefeldt, M. Johannsen, P. Rogalla; Berlin/DE
(c.kloeters@gmx.de)
Purpose: To evaluate the feasibility of renal function calculation based on perfusion imaging of the kidneys and to compare the results with scintigraphy in renal
donors.
Methods and Materials: 10 patients underwent a dynamic volume CT (320-slice
CT, Toshiba) of the kidneys. The imaging protocol consisted of 18 low-dose scans
covering both kidneys following intravenous injection of 60 ml of contrast material
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B-168
15:03
Comprehensive assessment of renal function and vessel morphology in
potential donors for kidney transplantation: An MRI-based approach
C. Rossi, A. Boss, F. Artunc, S. Yildiz, P. Martirosian, C.D. Claussen, H. Dittmann,
F. Schick, H.-P. Schlemmer; Tuebingen/DE
(heinz-peter.schlemmer@med.uni-tuebingen.de)
Purpose: Evaluation of potential living kidney donors is an expensive and timeconsuming procedure. In this study, an MR-based protocol for comprehensive
assessment of renal function and kidney vessel morphology in potential kidney
donors is presented.
Methods and Materials: Eleven healthy candidates for kidney transplantation
(mean age 46p14) participated in the study. Dynamic MR-nephrography was
performed using a navigator-gated T1-weighted saturation-recovery MR sequence
(trueFISP or turboFLASH). Images were acquired up to 60 minutes after a bolus
injection of 4 ml of gadobutrol. The glomerular filtration rate (GFR) was evaluated
from the renal clearance of gadobutrol within the extra-cellular fluid volume by
exponential fitting of time-signal curves measured over the liver. MR-angiography
(MRA) was performed using a T1-weighted 3D-Flash sequence. The overall
measuring time resulted in approx. 80 minutes. For each subject, GFR data were
compared to the results of radionuclide scintigraphy with Technetium-labeled DTPA
from the same day.
Results: Renal anatomy and vascular status could be successfully obtained in all
subjects. GFR values estimated by MR-nephrography showed a good agreement
to the scintigraphy data (mean GFR from MR-nephrography, 115p24 ml/min per
1.73 m2; mean GFR from scintigraphy, 112p24 ml/min per 1.73 m2). The BlandAltman plot showed a mean difference in measurements pairs of -2p12 ml/min per
1.73 m2. All measurement points were comprised within p2 standard deviations
from the mean value.
Conclusion: Comprehensive assessment of renal anatomy, function, and vessel
morphology is feasible within one single MR examination. The proposed protocol
may find immediate clinical application in the preoperative assessment of potential
kidney donors.
B-169
15:12
Early stage of renal dysfunction: Quantitative diagnosis with contrastenhanced ultrasonography, an initial experience
W. Wang, Y. Dong, H. Ding, C. Li; Shanghai/CN (puguang61@126.com)
Purpose: To prospectively estimate the value of contrast-enhanced ultrasonography (CEUS) in the quantitative evaluation of renal cortex perfusion in patients
suspected with early stage of renal dysfunction, with renal scintigraphy as the
golden standard.
Methods and Materials: The study protocol was approved by the hospital review
board and each patient gave written informed consent. A total of 41 right kidneys in
41 consecutive patients (26 men, 15 women; mean age, 35 p 2 years) suspected of
early renal dysfunction were examined with conventional Doppler ultrasonography
(US) and CEUS. By an intravenous bolus injection of 1 ml SonoVue, a time-intensity
curve (TIC) was created with QLAB software (PHILIPS iU22 system). The slope
rate of elevation curve (A), descending curve (A), area under curve (AUC), derived
peak intensity (DPI) and time to peak (TTP) were measured in the renal cortex
with 5×5 mm ROI. Receiver operating characteristic (ROC) curves were used to
predict the dignositc criteria of CEUS quantitative indexes.
Results: DPI less than 12, A greater than 2 and AUC greater than 1,300 had high
utility in the early stage of renal dysfunction, with 81, 73 and 78% specificity, 76,
73 and 77% sensitivity, and 79, 73 and 78% overall accuracy. These results were
significantly better than those obtained with RI and PSV in US, which had no significant difference between different stages of early renal dysfunction.
Conclusion: CEUS can improve the early diagnosis of renal dysfunction. DPI, A
and AUC might be valuable quantitative indexes.
B-170
15:21
Quantitative evaluation of contrast-enhanced ultrasonograhpy in the
diagnosis of chronic ischemic renal disease in a dog model
Y. Dong, W. Wang, H. Ding, C. Li; Shanghai/CN (drdaisydong@gmail.com)
Purpose: To prospectively test, in a dog model of chronic ischemic renal disease
(CIRD), the hypothesis that real-time contrast-enhanced ultrasonography (CEUS)
can quantitatively evaluate the perfusion changes of renal cortex in the early
period.
Methods and Materials: In this animal care and use committee-approved study, the
model of CIRD was established in healthy dogs (10.0-12.0 kg, n = 5), by placing an
Ameroid ring on the distal portion of the right renal artery through operation. CEUS
was performed for the right kidney with an intravenous bolus injection of 0.6 ml
SonoVue every 1 week after operation. The slope rate of elevation curve (A) and
descending curve (A), area under curve (AUC), derived peak intensity (DPI) and
time to peak (TTP) were measured in the renal cortex using QLab software (PHILIPS
iU22). Comparisons between different stages were performed using random-effects
regression. After 4-16 weeks of continuous observation, histopathologic examinations were performed. The sensitivity of CEUS was compared with the blood serum
urea nitrogen (BUN) and serum creatinine (SCr) level.
Results: With the progress of CIRD, the dogs showed decreased enhancement and
delayed perfusion in the renal CEUS curve. The earliest significant changes happened 4 weeks after operation on DPI and TTP from (13.04 p 2.71) to (15.58 p 4.75)
dB and (9.03 p 2.01) to (10.62 p 6.04) sec (P 0.05). Significant change happened
11 weeks later on BUN and SCr (P 0.05).
Conclusion: In this dog test experiment, CEUS can display the perfusion changes
of CIRD in the early period.
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Breast
SS 302
Screening and diagnosis
Moderators:
R. Gruber; Vienna/AT
R. Holland; Nijmegen/NL
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Mammography positioning and radiation dose
J. Peters; Frankfurt/DE (j.peters@em.uni-frankfurt.de)
Purpose: The ML view has been replaced by the MLO view because MLO positioning shows more of the axillary tail of the breast tissue than the ML view.In
mammography screening programs radiation dose is an important issue. Thus we
compared the dose required for MLO and ML views.
Methods and Materials: In our breast center 38,800 women received mammographies between March 2007 until August 2008. 30,272 screening and 8,538
clinical mammographies were done. Thus 77,600 MLO views were obtained. In 520
cases additional ML views were necessary for needle localization of non-palpable
lesions, preparation for vacuumbiopsies and identification of peudolesions caused
by MLO-positioning. Mammographies were obtained with the full-field digital device
by Sectra. Radiation dose required for MLO and ML views were compared.
Results: Radiation dose applied in MLO views ranged between 0.420 and
0.110 mGy with an average of 0.646 mGy. In ML views the dose ranged between
0.33 and 0.82 mGy with an average of 0.495 mGy. Thus the ML view required a
considerably lower radiation dose than the MLO view.
Conclusion: Since MLO requires more radiation than ML-positioning mammographies are obtained with higher doses than necessary. Thus ML-positioning might be
reconsidered. If the axillary tail is not included completely an additional MLO view
may be necessary. But for the large number of women where the entire breast tissue
is included in the ML view, exposure is minimized. In addition spatial orientation for
surgeons and radiotherapists is more precise with ML-views.
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at 10 ml/s. Scanning parameters were 100 kV, 20-40 mAs, 0.5 s rotation time,
16 cm collimation, and 0.5 mm slice thickness for all dynamic scans. Patients were
pre-oxygenated through a mask. All patients were imaged routinely before living
kidney donation for complete renal evaluation. The study had ethics approval. Images were first registered for motion correction. ROIs were placed in the aorta as
the reference and within 10 levels in each kidney. The maximum-slope technique
was used for perfusion maps, Patlak-plot for calculation of renal clearance. Results
were compared to renal scintigraphy, performed within 2 days.
Results: All patients tolerated the scanning procedure well, including the 40 s
breathhold for the first 10 scans. Image registration failed in 2 patients necessitating
manual interaction. Perfusion images were colour-coded and showed little anatomical mismatch at the outer edges of the kidneys (1-3 mm). The CT clearance varied
from scintigraphy between p27%, the correlation was 0.66, the average clearance
in CT and scintigraphy were 91.4 and 103.5, respectively.
Conclusion: CT perfusion based on 320-slice dynamic volume CT allows for calculation of renal clearance with good correlation to scintigraphy. Image registration
appears to be crucial for motion correction.
Scientific Sessions
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14:09
Digital workflow for mammography screening purposes in Denmark
U. Anderrson; Helsingborg/SE (robert.ashby@carestreamhealth.com)
Purpose: To develop and fully utilise IT technology in a digital workflow to benefit
mammography screening in Denmark. To improve booking and communication
for participants and improved workflow productivity for clinicians, while fulfilling
European guidelines for mammography double-blind reading. The project scope
included the three regions of Sjealland, Hovedstaden and MidtJylland, representing
more than two-thirds of the Danish population.
Methods and Materials: Following a successful bid for Government funding, Ringsted Sygehus in the Sjaelland Region of Denmark initiated the development work
for a digital workflow module for mammography screening. Other professionals from
Hovedstaden and MidtJylland regions were invited to participate to understand how
the community can scale and take advantage of a digital workflow. Data captured
were input into a research programme, resulting in development of the solution.
Results: A double-blind reading module for radiologists is running in a digital environment, fulfilling European guidelines. Productivity gains include remote reading
capabilities, helping to utilise the shortage of expert mammography radiologists and
an online portal that allows screening participants to directly cancel and reschedule
appointments resulting in reduced administration.
Conclusion: The efficiency of mammography screening workflow has improved
with the identification of commonalities and proven efficiency gains between
regions. The improvements in administration and productivity will support the
Danish government’s strategy of full mammography screening across the country
by the end of 2008.
B-173
14:18
Screening with digital mammography: Has it increased our rate of biopsy
for microcalcifications?
J.M. Kerr, G. Hargaden, H.M. Fenlon, M.M. McNicholas, F.L. Flanagan; Dublin/IE
Purpose: To determine the effect of introduction of digital mammography on recall
rates, biopsy rates and benign biopsy rates for microcalcifications in a breast cancer
screening programme.
Methods and Materials: The BreastCheck (Irish National Breast Screening Programme) database for the period January 2000 to March 2008 was reviewed. The
patients recalled to assessment for microcalcifications, those biopsied at assessment for microcalcifications and the biopsy outcome were identified for 2 groups,
those who had analogue and digital screening mammographies. Comparison was
made between the two groups in terms of recall rates and biopsy rates for microcalcifications, as well as the biopsy outcome.
Results: 44.8 per 1000 patients screened in the analogue group and 36.7 per 1000
patients screened in the digital group were recalled to assessment. 7 per 1000
were recalled for microcalcifications in the analogue group and 8.1 per 1000 in the
digital group. 5.1 biopsies were performed per 1000 screened in the analogue group
and 5.9 per 1000 in the digital group. In the analogue group, there were 0.01 per
1000 B1, 2.16 per 1000 B2, 0.71 per 1000 B3, 0.15 per 1000 B4 and 2 per 1000
B5 lesions. In the digital group there were 0 B1, 2.74 per 1000 B2, 0.56 per 1000
B3, 0.28 per 1000 B4 and 2.35 per 1000 B5.
Conclusion: The proportion of patients recalled to assessment for microcalcifications is higher in patients screened with digital mammography. The number of
biopsies for microcalcifications is also higher. As well as identifying more malignant
microcalcifications with digital screening, the benign biopsy rate is increased.
B-174
14:27
Screen detected breast cancers and computer aided detection (CAD)
prompting in a multicentre prospective evaluation of CAD in the UK breast
screening programme
F.J . Gilbert1, J. James2, M.G. Wallis3, C.R.M. Boggis4, S.M. Astley4,
M.G.C. Gillan1, O.F. Agbaje5, S.W. Duffy5; 1Aberdeen/UK, 2Nottingham/UK,
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Cambridge/UK, 4Manchester/UK, 5London/UK (f.j.gilbert@abdn.ac.uk)
Purpose: Computer aided detection (CAD) systems have been developed that
use software-based detection algorithms to attract the film reader’s attention to
potentially abnormal features on a mammogram. Data from CADET II (a multicentre
randomised evaluation of single reading with CAD and double reading in the UK
breast screening programme) has been analysed to compare reader recall decisions in relation to the accuracy of CAD prompting.
Methods and Materials: Mammograms from 28,204 women attending routine
two-view screening mammography were independently double read (DR) and
separately single read using CAD (SRCAD). Two experienced radiologists retrospectively reviewed the 227 screen-detected cancer cases prior mammograms
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and pathology reports recording the number and location of any CAD marks in
relation to the tumour location.
Results: Of the 227 cancers detected complete data were available for 200 (88%)
cases. The cancer was marked by CAD in 175/200 (80%) of cases. There were
57 discordant recall decisions by the two reading regimes. Complete prompt data
were available in 50 cases. The CAD prompt was correctly placed in 20/25 cases
recalled by SRCAD and 17/25 cases where SRCAD did not recall (P = 0.52).
Tumour characteristics were similar in both groups although slightly more masses
and calcifications were recalled by SRCAD than not recalled (23/28) compared
to 19/29 (P = 0.23).
Conclusion: This suggests that while the single reader is being influenced by CAD,
further work is required to understand why prompted tumours are being ignored.
B-175
14:36
Evaluation of the performance of independent expert reading after double
reading: Is there a higher detection rate of breast cancer in an analysis of
102,744 diagnostic processes?
F.K.W. Schaefer, A. Katalinic, P.J. Schäfer, B.M. Order, C. Wefelnberg, W. Jonat,
I. Schreer; Kiel/DE (fschaefer@email.uni-kiel.de)
Purpose: To determine the performance of expert reading in symptomatic or women
at risk. All patients were examined in the project ‘quality assurance in breast cancer
diagnosis’ (the QuaMaDi Project). In Schleswig-Holstein/Germany this processorientated and comprehensive quality management project was implemented to
improve the standard of breast cancer diagnosis.
Methods and Materials: A prospective cohort between 2001 and 2005 with a total
of 59,514 patients and 102,744 mammograms was initiated. For independent second
reading, the images of mammography p ultrasound documents were sent to a second
radiologist. If results were scored as BI-RADS 4 or 5 and in case of dissent between
BI-RADS1/2 vs 3 vs 4/5, the image materials were sent to expert reading for arbitration
purposes. Abnormalities were defined positive, if biopsy findings revealed malignancy
and negative if biopsy findings or all examinations turned out to be benign.
Results: According to the study protocol 24,470 cases (23.8%) of all radiological
examinations were third-read by expert reading at the reference centre. Expert
reading revealed 50 additional cancers (50/1019, 70% by US, 30% by mammography) out of 62,006 cases. That implies 5.2% extra detected cancers by expert
reading (2/1000 examinations).
Conclusion: Supplementary expert reading resulted in a significant breast cancer
detection rate increase of 5.2%.
B-176
14:45
Sensitivity of a computer-aided detection system (CAD) applied to full field
digital mammography (FFDM) based on breast density
C. Romero, I. Herrera, C. Varela, A. Almenar, M. Garcia Hidalgo, J. Pinto; Toledo/ES
(babel10100@hotmail.com)
Purpose: To show the results of a CAD system (R2 Technology, version 5.4) applied
to digital mammograms according to breast density in a diagnostic setting.
Methods and Materials: This is a 1-year prospective study run by two radiologists’
expert on breast imaging (8 and 4 years of experience). They did single reading
of 9000 FFDM (MAMMOMAT® Novation DR Siemens, Germany) cases, which
were reported including the BI-RADS assessment code and the mammographic
density (BI-RADS 1-4). In addition, any change in opinion due to CAD results was
registered. The BI-RADS 4 and 5 were biopsied. All cancers underwent MRI and
histopathology confirmation.
Results: Out of the 9,000 cases, 138 were cancers. The CAD system correctly
marked 118 (sensitivity 86.6%, 95% CI = 81.1-90.8), and missed 20 (14.5%). The
sensitivity of the CAD system based on breast density was overall 1: 91.2%; 2: 93%;
3: 82%; and 4: 80.2%. Sensitivity for microcalcifications was 1: 100%; 2: 100%; 3:
92.3%; 4: 95%. Sensitivity for mass, asymmetry, and architectural distortion was1:
93.3%; 2: 87.5%; 3: 78.8%; 4: 63.6%. The false-positive rate was less than 2 per case.
8 to 18 months follow-up were done for detection of new false-negative results.
Conclusion: Breast density did not have a significant effect on the detection of
microcalcifications but did on the detection of masses, asymmetry, and architectural
distortion. Based on our results, it may be possible to do pre-screening in BI-RADS
1 and 2 density cases. We will complete the study by doing a 2-year follow-up to
determine any additional false-negative results.
Scientific Sessions
B-177
14:54
Purpose: To prospectively determine frequency, pathology and causes of false
negative assessment (FNA) in women recalled for suspicious screening mammography.
Methods and Materials: We included all 290,943 screening mammograms of
women aged 50-75 years, who underwent biennial screening mammography
between January 1, 1995 and January 1, 2006 in the Southern Netherlands.
Radiologic, pathologic and surgical data were collected of all 3513 recalled
women during 2-year follow-up. Tumor stages of false negatively assessed breast
cancers, defined as cancers diagnosed more than 3 months following recall, were
compared with those of cancers diagnosed within 3 months following recall and
with interval cancers.
Results: FNA occurred in 6.5% (97/1503) of all screen-detected cancers. FNA
cases comprised more ductal cancers in situ (26.8%) than did cancers diagnosed
3 months after recall (15.5%, p=0.004) or interval cancers (3.7%, p 0.001).
Invasive FNA cancers were smaller than interval cancers (T1a-c, 87.3 vs. 46.4%;
p 0.001) and less often showed axillary lymph node metastases (22.5 vs 48.2%;
p 0.001). FNA percentages significantly varied between hospitals that had
evaluated at least 500 recalled women each (range: 5.0% (20/401 cancers) to
9.1% (29/320 cancers; p=0.03)). Improper classification of cancers at diagnostic
mammography was the major determinant of FNA in these hospitals and comprised
64.4% of false negative assessments.
Conclusion: 6.5% of recalled women experienced a delay in breast cancer diagnosis, with significant performance variations between hospitals. Although tumor
stages of FNA cases are more favourable than those of cancers without diagnostic
delay or interval cancers, FNA may negatively affect long-term outcome.
B-178
15:03
Is CAD effective in detecting high risk breast lesions?
I. Leichter1, R. Lederman1, N. Merlet1, E. Ratner1, A. Manevitch1, Z. Gallimidi2,
A. Heyman-Reiss2; 1Jerusalem/IL, 2Haifa/IL (isaac.leichter@siemens.com)
Purpose: To evaluate the detection sensitivity of a CAD device on high-risk lesions,
which should be marked in screening mammography, since most high-risk lesions,
especially those with atypia must be surgically excised.
Methods and Materials: 154 pathology-proven FFDM malignant cases (113 invasive, 41 non-invasive), 19 cases with high-risk lesions (12 ADH, 7 LS) and 2706
normal cases were culled retrospectively, in a consecutive manner, from 6 screening facilities. A non-blinded radiologist recorded, for each malignant and high-risk
case, the location of the biopsied finding. All cases were run on a prototype CAD
device (Siemens) that detected and marked suspicious findings on the images.
Detection was assessed by comparing each CAD mark to the biopsied finding. The
CAD performance for the high-risk cases was compared with that of the malignant
cases. Each CAD mark on normal cases was considered false.
Results: The overall sensitivity of CAD for high-risk cases was 84.21% [95% CI:
(66.15, 100%)]. Of the high-risk cases, the ADH lesions yielded a detection sensitivity of 83.33%, while for LS lesions it was 85.71%. The CAD sensitivity for highrisk lesions was not significantly different from the sensitivity for invasive lesions.
The sensitivity for non-invasive lesions was significantly higher (p 0.06) than for
high-risk lesions. The number of false marks per case marked on the 2706 normal
cases was 1.24 [95% CI: (1.177, 1.303)].
Conclusion: The CAD performance for high-risk lesions is comparable to malignant
lesions, allowing CAD to assist the radiologist in identifying these lesions, most of
which require excisional biopsy.
B-179
15:12
Comparison of the performance of different professional groups of film
readers using computer-aided detection (CAD) in the CADET II trial
M.G. Wallis1, J. James2, C.R.M. Boggis3, O.F. Agbaje4, M.G.C. Gillan5,
S.M. Astley3, S.W. Duffy4, F.J. Gilbert5; 1Cambridge/UK, 2Nottingham/UK,
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Manchester/UK, 4London/UK, 5Aberdeen/UK
(matthew.wallis@addenbrookes.nhs.uk)
Purpose: Double reading of screening mammograms is more sensitive for the
detection of small breast cancers, but there is a shortage of trained radiologist
film readers. The CADET II trial-demonstrated single read supplemented by CAD
(SRCAD) had an equivalent cancer detection as double read (DR), but with an
increase in the recall rate. Data from the trial provided an opportunity to compare
the performance of different professional groups of film readers.
Methods and Materials: The trial was based at three UK screening centres and
involved a total of 27 film reading personnel: 15 consultant radiologists; 4 breast
clinicians or registrar radiologists; 8 advanced practitioner radiographers. Mammograms from 28,204 women attending routine two-view screening mammography
were double read (DR) and single read using CAD (SRCAD).
Results: The SRCAD reader was significantly more likely to recommend recall
than either of the DR readers (P 0.001). For the first DR reader, recall rates were
significantly (P 0.001) higher for radiographers than for consultant radiologists
(5.1% vs 3.4%). The breast clinicians/registrars had a similar recall rate as the
consultant radiologists (3.7%). For the second DR reader, the radiographers and
breast clinicians had significantly (P = 0.04) lower rates of recall than the consultant
radiologists (2.9 and 2.8% vs 3.4%). For SRCAD, the breast clinicians/registrar
radiologists were significantly (P = 0.002) more likely to recommend recall than
either the radiologists or the radiographers (5.9 vs 3.8% and 3.9%).
Conclusion: This suggests that SCRAD using radiographers could be a viable
alternative to the current double reading practice where at least one reader is
medically trained.
B-180
15:21
Triple negative breast cancer: Clinical presentation and multimodality
imaging characteristics
O. Woo, S. Huh, A. Yi, Y. Kim, K. Cho, H. Yong, B. Seo, E.-Y. Kang; Seoul/KR
(wokhee@unitel.co.kr)
Purpose: Triple-negative breast cancer (TNBC) is defined by the lack of expression
of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth
factor receptor 2 (HER-2). In this study, we evaluated the clinical presentations and
multimodality imaging findings of TNBC.
Methods and Materials: The medical records of patients who underwent surgical
operations for primary breast cancer at our institute were retrospectively reviewed.
Patients received mammography (n = 58), breast ultrasound (n = 58) or MR imaging
(n = 38). Clinical presentations, pathologic results and staging were reviewed and the
multimodality imaging findings were analyzed by two radiologists in consensus.
Results: Among 390 breast cancer patients, 58 (15%) were diagnosed with TNBC.
The mean lesion size was 3.7 cm (range, 1.1- 10.7 cm). Of 58, 47 (81%) were
symptomatic, while 11/58 (19%) were detected during screening mammography
or ultrasound. On mammography, a round or lobular shape (45%), circumscribed
margin (40%) and absence of microcalcifications (89%) were the main findings.
On ultrasound, a round or lobular shape (48%), circumscribed margin (43%) and
hypoechogenecity (96%) were the prominent findings. On MR imaging, although
16/38 (42%) showed benign morphologic characteristics, 32/38 (84%) presented
type III wash-out dynamic enhancement pattern. Of the 58 TNBC, 54 (93%) were
invasive cancers and 4 were DCIS. Regarding histologic grading, high-grade carcinomas were found in 52/58 (89%) of the TNBC.
Conclusion: TNBC more often present as high-grade interval cancers that show
benign morphologic appearances on multimodality imaging. Knowledge of the
characteristics of TNBC may provide earlier detection and proper diagnosis.
14:00 - 15:30
Room G/H
Head and Neck
SS 308
New techniques in tumor management
Moderators:
B. Lombay; Miskolc/HU
P. Piñero; Sevilla/ES
B-181
14:00
Additional value of DCE-CT for combined FDG-PET/CT in the outcome
prediction of patients with head and neck tumors
A. Abramyuk1, K. Zöphel1, S. Tokalov1, U. Haberland2, E. Klotz2, T. Herrmann1,
M. Baumann1, N. Abolmaali1; 1Dresden/DE, 2Forchheim/DE
(Andrij.Abramyuk@OncoRay.de)
Purpose: The higher FDG uptake measured using PET in head and neck tumors
(HNT) is associated with shorter survival. At the same time, the tumor blood
volume (TBV), which could be measured with dynamic contrast-enhanced (DCE)
CT, is also an important characteristic influencing both radio- and chemotherapy
outcome. The attempt of this work was to clarify whether implementation of DCE-
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Delayed diagnosis of breast cancer in women recalled for suspicious
screening mammography
L.S.F. Yo1, L.E.M. Duijm1, J.H. Groenewoud2, H.J. de Koning2, J. Coebergh2,
M.J.H.H. Hooijen3, L.V. van de Poll-Fransse1; 1Eindhoven/NL, 2Rotterdam/NL,
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Geldrop/NL (RONLDM@cze.nl)
Scientific Sessions
CT in pre-therapeutical FDG-PET/CT protocol could be of clinical relevance in
patients with HNT.
Methods and Materials: A total of 10 consecutive patients with histologically proven
HNT had been included into the study. Patients underwent FDG-PET/CT with DCECT component before treatment using a combined PET/CT scanner Biograph 16
(Siemens) and a double head power injector Injectron CT 2 (MedTron). TBV was
determined using modified Patlak analysis with a pixel-based prototype software
(Siemens). Follow-up time was 24 months for all surviving patients.
Results: Using FDG-PET/CT, it was shown that three patients with low FDG uptake
(SUVmax: 8 p 1) and five to seven patients with higher FDG uptake (SUVmax:15 p 4, P
= 0.004) were free of local recurrence. Using DCE-CT, it was found that all patients
with homogeneous tumor blood supply and high TBV (9.3 p 3.9 ml/100 ml tissue)
were without local recurrence, while two of three patients with heterogeneous tumor
blood supply and regions of low TBV (3.2 p 1.3 ml/100 ml tissue, P = 0.06) within
the tumor died during follow-up because of tumor recurrence.
Conclusion: According to our initial data, DCE-CT might possibly better predict
outcome of patients with HNT than FDG-PET/CT. The data justify initiating a more
extensive prospective study.
B-182
14:09
Quantitative modifications of TNM-staging and therapeutic intent by
18 FDG-PET/CT in patients scheduled for radiation therapy suffering from
head and neck-cancer
S. Kvasny, A. Abramyuk, A. Koch, K. Zoephel, S. Appold, N. Abolmaali; Dresden/DE
(Slavomir.Kvasny@mailbox.tu-dresden.de)
Purpose: To evaluate the modifications by 18 FDG-PET/CT on conventional pretreatment staging in patients suffering from head&neck-cancer (HNC)scheduled
for radiation therapy (RT).
Methods and Materials: 102 consecutive patients scheduled for RT suffering from
HNC who received no previous treatment underwent conventional morphologic
staging using CT and MRI and a subsequent 18 FDG-PET/CT staging. Pre-PET/
CT staging was done on an outpatient basis, PET/CT staging was done by three
board certified specialists (diagnostic radiologist, nuclear medicine physician,
radiation oncologist) in consensus.
Results: T-, N- and M-stage was increased in 10%, 8%, and 13%, reduced in 35%,
26%, and 1%, and remained unchanged in 55%, 66%, and 86%, respectively.
The clinical stage was increased in 8%, reduced in 16%, and not changed in 76%
of patients. Statistically, there was a significant improvement of T- and N-stage
(p=0.002; p=0.0006) and worsening of M-stage (p=0.001). The clinical stage was
not significantly modified d (p=0.1). As a result therapeutic intent was changed in
12% of the patients from curative to palliative, 2% of patients went from palliative
to curative intent. In 86% therapeutic intention remained unchanged. Overall, FDGPET/CT reduced radiation therapy volumes mainly in patients in which the T- and
N-stage was changed and modified the therapeutic intent in patients in which the
M-stage was changed.
Conclusion: 18 FDG-PET/CT in HNC-patients is advantageous to decide the
therapeutic intent before RT-planning in 14% of the patients. Additionally, side
effects of RT are reduced by shrinkage of RT-volumes. Studies on the prognostic
relevance for these patients are ongoing.
B-183
14:18
Modern imaging of head and neck tumours: 3 T-MRI, DWI, PET-CT
J. Frühwald-Pallamar, J.M. Patsch, A. Herneth, M. Formanek, C. Czerny; Vienna/AT
(julia.fruehwald-pallamar@meduniwien.ac.at)
Purpose: To assess the additional information of diffusion-weighted imaging
(DWI) and PET-CT in the preoperative evaluation of patients with biopsy-verified
ENT malignancy.
Methods and Materials: A total of 13 patients with proven ENT malignancies,
who underwent conventional MR imaging, DWI and PET-CT for preoperative
evaluation were retrospectively analysed. MR imaging at 3 Tesla (Philips, Archiva)
with a dedicated head and neck coil included coronal STIR, axial STIR and axial
T1-weighted sequences before and after i.v. contrast media application. Additional
two different types of diffusion-weighted sequences were measured: in the sagittal plane DWI_MSh FH and in the axial plane DWIBS was used (b-value: 0-800),
and the ADC was calculated. An 18-FDG-PET-CT was performed on a Siemens
biograph scanner after the i.v. application of CT contrast material and 18-FDG-PET
tracer to acquire additional information as pathological lymph nodes outside the
MR scanning range, metastasis and second primary tumours (as it often occurs
in patients with ENT squamous cell carcinomas).
Results: The final histopathological results included squamous cell carcinoma,
sarcoma, adenocarcinoma and metastasis. In most of the cases, PET-CT had a
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higher sensitivity and specificity in detecting lymph node metastasis because of a
higher glucose metabolism. In one case of an angiosarcoma, neither the tumour
nor the lymph node metastasis showed an increased tracer uptake in FDG-PETCT, whereas in the DWI sequences the pathologic lymph node could be clearly
diagnosed.
Conclusion: DWI offers a higher diagnostic accuracy than conventional MRI
sequences in detecting lymph node metastasis, especially in tumours that are
negative on PET-CT.
B-184
14:27
Dynamic contrast-enhanced MR imaging: A reliable diagnostic tool for
recurrent head and neck tumors
E. Kamel, P. Pasche, R. Meuli, P. Hauser, I. Borchardt, P. Schnyder, B. Duvoisin;
Lausanne/CH (Mohamed-ehab.kamel@chuv.ch)
Purpose: To investigate the role of Dynamic Contrast-Enhanced MR Imaging
(DCE-MRI) in the follow-up of patients with head and neck tumors.
Methods and Materials: Twenty-seven patients were recruited. DCE-MRI was
performed as a part of regular posttherapy follow-up (n = 20) or for clinical suspicion
of local disease recurrence (n = 7). Axial dynamic T1-weighted fat sat sequences
were performed in a 3-T MR scanner for a total duration of 10 minutes after contrast
administration. An operator-defined region of interest was placed in the maximal
enhancement area (s) of the tumor bed. A time-intensity curve was constructed.
The time to maximal enhancement (Tmax), enhancement ratio at 3 min (ER3 min), and
washout ratio at 10 min (WR10 min) were measured. Per-lesion DCE-MRI findings were
correlated with histologic analysis or with clinical and radiological follow-up.
Results: There was a significant difference between Tmax, ER3 min and WR10 min of
recurrent lesions and those of posttherapy tissue remodeling (2.2 min, 19%, and
20% vs. 8.3 min, 12%, and 6%, P 0.05). Among 12 recurrent lesions in 9 patients,
DCE-MRI detected 11/12 (91%) of these foci. One false negative result was due to
microscopic disease residue. Two radionecrotic lesions were responsible for false
positive DCE-MRI results in 2 patients. In the remaining 16 patients, true negative
DCE-MRI findings were confirmed. Accordingly, the sensitivity, specificity, and accuracy of DCE-MRI were 91%, 89% and 90%, respectively.
Conclusion: DCE-MRI can be integrated in the diagnostic work-up of patients with
or without clinical or radiological suspicion of recurrent head and neck tumors.
B-185
14:36
Outcome prediction after surgery and chemoradiation of squamous cell
carcinoma in the upper aerodigestive tract: Comparison of perfusion CT
versus tumor volume
S. Bisdas1, I. Burck2, S.K. Anand3, T. Day3, G. Glavina4, M.G. Mack2,
Z. Rumboldt3; 1Tübingen/DE, 2Frankfurt a. Main/DE, 3Charleston, SC/US,
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Split/HR (sbisdas@yahoo.com)
Purpose: To examine whether perfusion CT (PCT) may predict outcome in patients
with squamous cell carcinoma (SCCA) of the upper aerodigestive tract after surgical
excision with chemoradiation.
Methods and Materials: Twenty-six patients with SCCA were examined before
treatment. The primary site was oral cavity in 6, oropharynx in 7, and hypopharynx
in 8 patients; there were eleven T2, six T3 and four T4 tumors. The PCT data was
processed to obtain blood flow (BF), blood volume (BV), mean transit time (MTT),
and permeability surface area product (PS). Tumor volume was also calculated.
Follow-up was performed with PET/CT and endoscopy. Pearson correlation coefficient was used for comparison between the subgroups. A regression model was
constructed to predict recurrence based on the following predictors: age, gender,
tumor (T) and nodal (N) stage, tumor volume, and PCT parameters.
Results: BFmean, BFmax, BVmean, BVmax, MTTmean, PSmean, and PSmax values were
significantly different between patients with and without tumor recurrence
(0.0001p 0.04). T stage, tumor volume, N stage, BFmax, BVmax, MTTmean, and
radiation dose (p 0.001) were independent predictors for recurrence. Cox proportional hazards model for tumor recurrence revealed significantly increased risk
with high tumor volume (p=0.00001, relative risk [RR] 7.1), low PSmean (p=0.0001,
RR 14), and low BFmax (p=0.002, RR 5.6).
Conclusion: PCT parameters have a predictive role in patients with SCCA treated
with surgical surgery and adjuvant chemoradiation.
Scientific Sessions
B-186
14:45
Purpose: The aim was to determine the diagnostic accuracy and additional value
of diffusion-weighted imaging (DWI) for detection of malignant lymph nodes in head
and neck squamous cell carcinoma (HNSCC).
Methods and Materials: A total of 219 lymph nodes, predominantly smaller than
10 mm (95.4%), in 16 consecutive patients were evaluated on MRI (1.5 Tesla).
Lymph nodes were evaluated for maximum short axial diameter, morphological
criteria and apparent diffusion coefficient (ADC) values (b = 0 and b = 1,000 sec/
mm2). Diagnostic parameters, sensitivity and specificity with diagnostic odds ratio
(DOR), were compared for the various MRI criteria. The AUCs of ROC curves were
derived from multivariate logistic regression models, which included different sets
of MRI criteria. The AUCs were compared to evaluate the added value of ADC to
the other MRI criteria.
Results: The optimal ADC threshold was 1.0 × 10-3 mm2/sec. Using this value
as the cut-off point, sensitivity and specificity were 92.3 and 83.9%, respectively.
When used in combination with size and morphological criteria, ADC value 1.0
× 10-3 mm2/sec was the strongest predictor of the presence of metastasis (DOR =
97.6; 95% CI: 97-982). A model that added ADC values to the other MRI criteria
performed significantly better than a model without ADC values: AUC = 0.98 versus
AUC = 0.91 (P = 0.036).
Conclusion: In this study, with predominantly small lymph nodes, the ADC criterion
is the strongest independent predictor of the presence of metastasis, followed by
the border criterion. The use of ADC values in combination with other MRI criteria
can significantly improve the discrimination between cervical lymph nodes with
and without metastasis.
B-188
14:54
Differentiation of primary parotid gland tumors: Does a combination of
diffusion-weighted echo-planar MRI and magnetization transfer imaging
offer diagnostic improvement?
C.R. Habermann, C. Arndt, J. Graessner, F. Reitmeier, M. Jaehne, G. Adam;
Hamburg/DE (c.habermann@uke.uni-hamburg.de)
Purpose: To investigate the potential of diffusion-weighted (DW) echo-planar
imaging (EPI) in combination with magnetization transfer imaging in differentiating
primary parotid gland tumors.
Methods and Materials: A total of 145 consecutive patients with suspected primary
tumor of the parotid gland were prospectively examined. A DW EPI sequence and a
single-slice T1-weighted GRE sequence in in-phase and opposed-phase technique
prior and post 1 kHz off-resonance pulse were acquired. ADC maps and MT images
were digitally transferred to MRIcro and evaluated with a manually placed irregular
region of interest (ROI) containing the entire tumor. For comparison of the results,
the two-tailed Student’s t test with Bonferroni correction for multiple testing was
used, based on the mean ADC values for each patient.
Results: In 129 patients, 14 different subtypes of primary neoplasms of the parotid
glands could be verified histologically. Based on the ADC values, pleomorphic
adenomas could be differentiated from all entities (P 0.001) except myoepithelial
adenomas (P = 0.054). Using MTR, these two entities could not be discriminated as
well (P = 0.394). DW imaging failed to differentiate Warthin tumors from mucoepidermoid carcinomas, acinic cell carcinomas and basal cell adenomas (P = 0.094
to 0.604), whereas MTI was able to differentiate Warthin tumors and basal cell
adenomas (P = 0.004). DW imaging failed in differentiating myoepithelial adenomas
and mucoepidermoid carcinomas from basal cell adenocarcinomas (P = 0.082;
0.569), whereas MTI was able to differentiate these entities (P = 0.032; 0.014).
Conclusion: DW imaging has a potential in differentiating subtypes of parotid gland
tumors. Combining this technique with MTI improves the noninvasive approach.
B-189
15:03
Can quantitative diffusion-weighted MRI differentiate benign and malignant
cold thyroid nodules? Initial results in 25 patients
C. Schueller-Weidekamm, G. Schueller-Weidekamm, C. Czerny, A. Herneth;
Vienna/AT (claudia.schueller-weidekamm@meduniwien.ac.at)
Purpose: The characterization of cold nodules of the thyroid gland is mandatory
as approximately 20% of these nodules are of malignant origin. The purpose of
this study was to evaluate the dignity of cold thyroid nodules using quantitative
diffusion-weighted MRI (DWI).
Methods and Materials: In 25 patients with cold nodules on scintigraphy and
suspicious findings at fine-needle aspiration, thyroid carcinoma was suspected. In
these patients, cold nodules and the normal parenchyma of the contralateral thyroid
lobe were prospectively investigated with quantitative DWI (echo-planar imaging
sequence; maximum b-value 800 sec/mm2) prior to surgery. The differences in the
mean apparent diffusion coefficient (ADC) values in benign and malignant nodules
were tested by using a Mann-Whitney-U test.
Results: Histologically, there were 20 carcinomas with a minimum size of 8 mm
and five adenomas. The mean ADC values (in 10-3 mm2/sec) differed significantly
between carcinoma, adenoma, and normal parenchyma (P 0.05). The ranges
(95% confidence interval) of the ADC values for carcinoma (2.43-3.037), adenoma
(1.626-2.233), and normal parenchyma (1.253-1.602) showed no overlap. When
an ADC value of 2.25 or higher was used for predicting malignancy, the highest
accuracy of 88%, with 85% sensitivity and 100% specificity, was obtained.
Conclusion: Quantitative DWI seems to be a feasible tool by which to differentiate
thyroid carcinomas from adenomas; however, further studies are required including
larger number of patients to confirm our results.
B-190
15:12
Interobserver agreement at the malignant thyroid nodules with
conventional ultrasound (US) and US elastography: Prospective study
S. Park; Incheon/KR (shpark@gilhospital.com)
Purpose: To investigate interobserver agreement at the malignant thyroid nodules
with conventional B-mode US and real-time free hand US elastography.
Methods and Materials: Between December 2007 and February 2008, 42
patients (19-73 years; 45.0p 12.2 years) with 52 thyroid nodules were examined
with conventional B-mode US and real-time free hand US elastography. All the
patients were scheduled to undergo thyroid surgery due to thyroid nodule having
been proven to be malignant on aspiration cytology. Three experienced, board
certified radiologists independently performed conventional US and elastography
and analyzed US images. Analysis in conventional US included composition
(solid, cyst, mixed-echoic, sponge), nodular echogenicity (hyperechoic, isoechoic,
hypoechoic, marked hypoechoic), margin (well-circumscribed, microlobulated or
irregular), calcification (micro, macro, negative, mixed), shape (parallel, non-parallel)
and final assessment (cyst, probably benign, low suspicious, suspicious). Ueno
classification and odds ratio were made by using US elastography. Interobserver
agreement was evaluated with Spearman correlation analysis except the area ratio
(using Pearson correlation analysis).
Results: Stastistically significant (p .05) concordance between 3 radiologists was
found for most US features except for nodular echogenicity and margin of thyroid
nodules on conventional US. The highest value of concordance was achieved in
composition, followed by underlying parenchymal echogenicity, shape, calcification and final assessment. The least concordant finding was margin and nodular
echogenicity on conventional US. However, there was no stastistically significant
concordance in Ueno classification and area ratio on elastography.
Conclusion: Conventional US made stastistically significant concordance between
radiologists in most of US features; however, US elastography did not make reliable
interobserver agreement at malignant thyroid nodule.
14:00 - 15:30
Room I
Vascular
SS 315
Magnetic resonance angiography
Moderators:
V. Iaccarino; Naples/IT
A. Tóth; Budapest/HU
B-191
14:00
Intraindividual comparison of time-of-flight (TOF)- and phase-contrast
angiography (PCA) with time-resolving 4D-keyhole angiography of
cerebral vessels
B. Buerke, T. Niederstadt, C. Bremer, W. Heindel, B. Tombach, T. Allkemper;
Münster/DE
Purpose: To investigate the feasibility of high-resolution four-dimensional (4D)
CE-MRA of the brain using a combination of keyhole data acquisition and parallel
imaging (SENSE) compared to non-enhanced techniques (TOF- and PC-MRA).
Methods and Materials: A total of 46 patients suspected with intracranial vascular
pathologies were examined on a 1.5 T scanner (Intera 1.5, Philips, The Netherlands) with the help of a SENSE-capable head coil. Contrast-enhanced MRA of
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Diagnostic accuracy of diffusion-weighted imaging for discrimination of
malignant lymph nodes in head and neck squamous cell carcinoma
R.B.J. de Bondt1, M.C. Hoeberigs1, P.J. Nelemans1, W.M.L.L. Deserno2,
C. Peutz-Kootstra1, B. Kremer1, R.G.H. Beets-Tan 1; 1Maastricht/NL, 2Almelo/NL
(rbj.de.bondt@mumc.nl)
Scientific Sessions
the intracranial vessels was performed with 1M Gadobutrol (0.1 mmol/kg bw, flow
rate 2 cc/sec, followed by 20 ml saline flush, fixed delay 10 sec) using a 4D-keyhole
acquisition technique (temporal resolution 7.3 sec, spatial resolution 0.39 x 0.39 x
0.7 mm). Comparative TOF-MRA (voxel size 0.31 x 0.31 x 0.70 mm) and PCA (0.90
x 0.90 x 0.80 mm) were performed in the same session. Qualitative evaluation was
performed by two experienced radiologists with regard to vessel contrast, venous
overlay and overall image quality. Quantitative evaluation included SNR and CNR
measurements in arterial and venous intracranial vessels.
Results: The high temporal and spatial resolution of the 4D-keyhole acquisition
technique enabled proper discrimination of arterial and venous vessel enhancement
in 40/46 patients, providing an excellent image quality in most of the cases (38/46).
Compared to non-enhanced techniques, the diagnostic impact of the 4D-keyhole
technique was significantly higher due to discrimination of arterial and venous vessels. Furthermore, its total acquisition time was significantly shorter (4D-keyhole:63
sec,TOF-MRA: 6 min 17 sec, PCA: 8 min 18 sec). Quantitative analysis revealed
comparable SNR and CNR values of keyhole, TOF- and PC-MRA data sets.
Conclusion: The 4D-keyhole CE-MRA of the intracranial vessels is a robust diagnostic imaging tool that enables proper discrimination of the arterial and venous
vessels within a total acquisition time of 63 sec, offering the potential to replace
TOF- and PC-angiography.
B-192
14:09
Determination of the optimal keyhole percentage for time-resolved, highresolution 3D keyhole CE-MRA: Results of an experimental study
B. Buerke1, C. Bremer1, D. Maintz1, H. Kooijman2, B. Tombach1, W. Heindel1,
T. Allkemper1; 1Münster/DE, 2Hamburg/DE
Purpose: To experimentally determine the optimal keyhole-percentage (ratio
between the central, dynamic and the peripheral, static part of k-space) for timeresolved, 3D CE-MR angiography using the CENTRA keyhole technique combined
with parallel imaging (SENSE).
Methods and Materials: Plastic tubes with diameters of 2; 5; 7; 9; 13; 15 mm were
embedded in an agarose gel. Saline solution was pumped through these tubes
with a pulsatile flow (450 ml/s,70 BPM) to simulate physiological conditions. Timeresolved 3D-keyhole CE-MRA scans were performed on a 1.5 T clinical imaging
system (Gyroscan Intera®, Philips Medical Systems, The Netherlands) immediately
after manual injection of 2 ml 1M Gadobutrol® (Bayer Schering Pharma, Berlin,
Germany). CE-MRA was repeated using different keyhole percentages of 6; 9;
14; 18; and 27% (temporal resolution: 1.3 s; 2 s; 3.1s; 3.9 s; 5.9 s) at a constant
spatial resolution of 0.39x0.39x0.7 mm. Qualitative evaluation was performed by
two experienced radiologists with regard to tube delineation, artifacts, and image
contrast. Spatial accuracy was quantitatively assessed by measuring the apparent
MRA tube diameter and comparing it to the genuine diameter.
Results: The spatial accuracy decreased with increasing temporal resolution. Data
sets acquired with keyhole percentages 14% suffered from severe pulsation artifacts, image blurring and insufficient spatial accuracy due to apparently increased
tube diameters, especially for smaller tube diameters 5 mm. None of these effects was noticeable for data sets acquired with keyhole percentages r14%. Best
image quality and highest spatial accuracy was observed for the lowest temporal
resolution (keyhole percentage 27%).
Conclusion: To guarantee for optimal spatial accuracy, temporal resolution, and
image quality, time-resolved, high-resolution 3D keyhole CE-MRA data sets should
be acquired with a keyhole percentage of 14-18%.
B-193
14:18
Pre-surgical localisation of the artery of Adamkiewicz with time-resolved
MRA at 3.0 T
T.A. Bley, C. Duffek, C. Francois, M. Schiebler, T. Grist, S. Reeder; Madison, WI/US
(tbley@uwhealth.org)
Purpose: Patients undergoing thoracic aortic aneurysm (TAA) repair are at risk
of paraplegia resulting from injury to the great radiculomedullary artery, “artery of
Adamkiewicz” (AOA). Visualization of the AOA is challenging because this artery is
0.5 mm in diameter and its origin is highly variable. Preoperative visualization for
surgical planning may be helpful to avoid paralysis. The purpose of this work was to
use time-resolved MRA for visualization of the artery of Adamkiewicz at 3 T.
Methods and Materials: A total of 55 patients were scanned on a 3.0 T scanner
(HDx, TwinSpeed, GE) using time-resolved MR. Imaging parameters included: sagittal acquisition from T7 to L2, TR/TE = 4.4/1.7 ms, fractional TE, “whole” gradient
mode, flip = 23o, BW = p50 kHz, FOV = 24 x 17 cm, slice = 1.4 mm, 256 x 256 x
54 matrix and 12 phases. True spatial resolution was 0.9 x 0.9 x 1.4 mm3, zero-filled
to 0.5 x 0.5 x 0.7 mm3. Effective temporal resolution was 12.0 s; 0.2 mmol/kg of
gadobenate dimeglumine (Bracco, Princeton).
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Results: Excellent visualization of the AOA was achieved in over 85% of cases.
Utilizing time-resolved imaging, the AOA could be discerned from the anterior
spinal vein that had the strongest opacification in later time phases of the timeresolved MRA.
Conclusion: Time-resolved imaging is needed because timing of the arterial phase
is difficult in the presence of large aneurysms. Arterial phases were achieved that
help to distinguish the ASA from the anterior spinal vein, which has a similar course
and can be confused with the anterior spinal artery. High spatial resolution imaging
at 3.0 T using a dedicated spine coil, double dose contrast and nitroglycerine were
steps taken to maximize visualization of the AOA.
B-194
14:27
A total atherosclerotic score for whole-body MRA is related to traditional
cardiovascular risk factors, IMT and manifest cardiovascular disease
T. Hansen1, H. Ahlström1, J. Wikström1, L. Lind1, L. Johansson2; 1Uppsala/SE,
2
Mölndal/SE (tomas.hansen@radiol.uu.se)
Purpose: To create a scoring system for whole body magnetic resonance angiography (WBMRA) that allows estimation of atherosclerotic-induced luminal narrowing
in the arterial tree and to determine whether the traditional cardiovascular (CV)
risk factors included in the Framingham risk score (FRS), intima media thickness
(IMT) and manifest CV disease were related to the total atherosclerotic score (TAS)
in an elderly population.
Methods and Materials: A total of 306 subjects aged 70 were recruited from the
general population and underwent WBMRA with a clinical 1.5 T scanner (Gyroscan
Intera, Philips Medical system) and with administration of i.v. injection of 40 ml
gadodiamide (Omniscan, GE Healthcare). The arterial tree was assessed according to its degree of stenosis or occlusion and a TAS was created. The IMT were
measured in the common carotid artery with ultrasound.
Results: FRS correlated with TAS (r = 0.30, P 0.0001). Of the parameters included
in the FRS, male gender (P 0.0001), systolic blood pressure (P = 0.0002), cigarette
pack years (P = 0.0008) and HDL cholesterol (P = 0.008) contributed to the significance, while blood glucose and LDL cholesterol did not. The IMT were correlated
to TAS (P 0.0001). The group with CV disease had a significantly higher mean
TAS value (38.8) than the group without CV disease (23.3; P = 0.0006).
Conclusion: The significant relation towards traditional CV risk factors, IMT and
manifest CV disease indicates that the proposed scoring system could be of value
for assessing atherosclerotic-induced luminal narrowing.
B-195
14:36
Detection of reperfused pulmonary arteriovenous malformations with
contrast-enhanced magnetic resonance angiography
G.K. Schneider1, A. Massmann1, M. Katoh1, U.W. Geisthoff2, A. Buecker1;
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Homburg a.d. Saar/DE, 2Cologne/DE (dr.guenther.schneider@uks.eu)
Purpose: To evaluate contrast-enhanced magnetic resonance angiography (CE
MRA) for detection of reperfused pulmonary arteriovenous malformations (PAVMs)
after coil embolization in patients with hereditary hemorrhagic telangiectasia
(HHT).
Methods and Materials: Between February 1999 and March 2008, 256 patients
with diagnosed HHT, or first degree relatives, underwent MRI screening for cerebral, pulmonary and visceral manifestations of HHT. Retrospective analysis was
performed for patients with reperfused PAVMs after coil embolization. CE-MRA
(gadobenate dimeglumine, 0.1 mmol/kg body weight) diagnosis of reperfused
PAVM was confirmed by catheter angiography (CA).
Results: A total of 128 PAVM in 48 patients were embolized using platinum coils.
Complete occlusion of the feeding vessels was achieved in each case. Follow-up
CE-MRA revealed reperfusion of 6/128 embolized PAVMs in 5/48 patients. Additionally, CE-MRA revealed six reperfused PAVMs in three patients who had undergone
embolization elsewhere. All patients with reperfused PAVMs underwent CA and
reembolization. No additional reperfused PAVMs were detected on CA. Reperfusion
was due to biodegradation of coils caused by corrosion of tungsten filaments (two
PAVMs in one patient), insufficient coil packing (eight PAVMs in five patients) and
opening of collateral feeding vessels (two PAVMs in two patients).
Conclusion: Reperfusion of PAVMs may occur over an extended time interval.
Consequently, regular follow-up is mandatory. Our study shows that CE-MRA
is a useful technique for follow-up of treated PAVMs. Unlike CT imaging, which
may be compromised by metal artifacts arising from the embolization material,
CE-MRA provides excellent image quality and is able to accurately detect PAVM
reperfusion.
Scientific Sessions
B-196
14:45
Purpose: To intraindividually compare 0.1 mmol/kg doses of gadobenate dimeglumine (Gd-BOPTA) and gadopentetate dimeglumine (Gd-DTPA) for contrastenhanced MRA (CE-MRA) in patients with peripheral arterial occlusive disease
(PAOD).
Methods and Materials: Ninety-six patients underwent two CE-MRA examinations at 1.5 T using standard 3D spoiled GRE sequences. Contrast administration
was randomized: 52 patients received Gd-BOPTA first; and 44 patients received
Gd-DTPA first. Images were evaluated on-site for technical adequacy and vessel
visualization quality and off-site (3 independent blinded readers) in matched-image
pairs for vessel delineation, pathology detection/exclusion and diagnostic preference. Quantitative contrast enhancement (contrast-to-noise ratio [CNR]) of the
pelvis, thigh and calf was assessed. Data were compared between groups using
the Wilcoxon signed-rank test while interreader agreement was assessed using
generalized + statistics.
Results: Gd-BOPTA was associated with significantly fewer technically inadequate segments (20/564 [4%] vs. 67/564 [12%]; p 0.0001) and with significantly
more segments of good or excellent quality (491/564 [87%] vs. 413/562 [73%];
p 0.0001). Off-site blinded readers 1, 2 and 3 preferred Gd-BOPTA overall in 75
(82%), 75 (82%) and 70 (76%) patients, respectively, compared with 4 (4%), 7 (8%)
and 8 (9%) patients for Gd-DTPA (pb0.0001; all readers). Similar highly significant
(pb0.0001) preference for Gd-BOPTA was expressed by each reader for all other
qualitative endpoints in each territory. Three-reader agreement was good to excellent
for each endpoint (+=0.46 [73% of patients] for diagnostic preference). Significantly
(pb0.0001) higher CNR was noted for Gd-BOPTA in each territory.
Conclusion: Gd-BOPTA at 0.1 mmol/kg bodyweight is significantly superior to
equivalent-dose Gd-DTPA for CE-MRA of PAOD.
B-197
14:54
Blood pool versus non-blood pool paramagnetic contrast agents in
the MRA evaluation of peripheral arterial occlusive disease (PAOD) in
comparison to digital subtraction angiography (DSA)
M. Di Terlizzi, R. Ambrosini, R. Fossaceca, A. Carriero; Novara/IT (mditer@gmail.com)
Purpose: To evaluate the diagnostic accuracy of high-resolution MRA sequences
in the assessment of PAOD using a blood pool versus a conventional paramagnetic
contrast agent, as compared to DSA.
Methods and Materials: A total of 13 consecutive Type I diabetic patients with
known PAOD (10 males, 3 females; mean age 62 years), scheduled for lower leg
PTA, underwent MRA twice on a 1.5 T system using both an extracellular contrast
agent (Gadobenate Dimeglumine, MultiHance, Bracco Diagnostic Inc, Italy) and
an intravascular contrast agent (Gadofosveset Trisodium, Vasovist; Bayer Schering
Pharma AG, Germany). 10 ml of Gadofosveset were injected at 1 ml/s; after the
first-pass, a steady-state high-resolution acquisition was performed (voxel size = 0.5
x 0.5 x 0.5 mm, AT = 3 min). Within 2 weeks, the same patients underwent a second
first pass MRA using 0.2 mmol/kg at 1 ml/s Gadobenate. All patients underwent
DSA. Vascular tree was divided into 16 segments, with a total of 416 segments to
be evaluated. Two experienced radiologists blindly evaluated the MRA datasets for
significant vascular stenoses ( 50%) on a per-segment basis.
Results: A total of 366/416 (87.9%) and 374/416 (89.9%) arterial segments
were visualized during first-pass MRA using Gadofosveset and Gadobenate,
respectively, with no statistically significant differences in detection and grading
of stenoses. Steady-state Gadofosveset MRA allowed the correct evaluation of
408/416 segments (98%). Sensitivity, specificity and diagnostic accuracy were 85%,
84%, and 88% for first-pass MRA and 92.2%, 92.4%, and 97.5%, for steady-state
Gadofosveset-MRA.
Conclusion: Steady-state Gadofosveset-MRA appears as a robust imaging
technique for the assessment of PAOD, with a diagnostic accuracy comparable
to DSA.
B-198
15:03
Asymptomatic deep vein thrombosis and incidental venous findings in 139
patients with peripheral artery disease referred for peripheral MRA with a
blood pool contrast agent
G.M. Kukuk, D.R. Hadizadeh, U. Fahlenkamp, A. Koscielny, F. Verrel, H.H. Schild,
W.A. Willinek; Bonn/DE (Guido.Kukuk@ukb.uni-bonn.de)
Purpose: Prospective assessment of lower extremity veins as an adjunct to peripheral MRA with a blood pool contrast agent (BPCA) in patients with suspected
or known peripheral artery disease (PAD).
Methods and Materials: 139 patients with PAD were examined after single injection of
the BPCA Gadofosveset Trisodium (Vasovist, Bayer Schering Healthcare, Germany)
on a 1.5 T whole body MRI. First pass and steady state MRA was acquired for the
evaluation of PAD with effective voxel sizes of 0.99 mm³ (upper legs) and 0.49 mm³
(lower legs). Steady state images were assessed by 2 radiologists in consensus in
order to identify venous disease (deep vein thrombosis (DVT), varicosis, fistulae, etc).
and to determine suitable veins for bypass graft surgery. Duplex ultrasound performed
by an independent third reader served as the standard of reference.
Results: In 49/139 (35%) MRA with BPCA revealed additional venous disease.
Incidental DVT was found in 3/139 (2%) patients, varicosis was present in 42/139
(30%) and arterio-venous fistula was diagnosed in 1/139 (0.7%). 43 of 139 patients
(31%) were scheduled for coronary bypass surgery (6/43) or peripheral bypass
surgery (37/43). MRA with BPCA allowed for mapping of veins suitable for bypass
surgery in all 43/43 patients eligible for bypass surgery. All imaging findings were
confirmed by Duplex US and intraoperative results.
Conclusion: Peripheral MRA with a BPCA allows for diagnosis of incidental, but
relevant venous disease including asymptomatic DVT in patients with PAD and
may become a promising clinical indication to determine concomitant arterial and
venous disease.
B-199
15:12
Steady state imaging with blood pool contrast agent MRA in patients
with critical lower limb ischaemia for venous mapping bypass graft
assessment: Initial experience
G.H. Roditi, D. Orr; Glasgow/UK (gilesroditi@mac.com)
Purpose: Assess potential of MRA with blood pool contrast agent compared to
ultrasound for lower limb vein mapping in assessing conduit suitability.
Methods and Materials: Ethics committee approved study with informed consent
from patients with Fontaine stage III or IV lower limb ischaemia. MRA with blood pool
contrast agent, hybrid dual injection technique with dynamic MRA at tibial station,
then stepping table bolus chase MRA and subsequent high resolution steady state
imaging of calves and thighs. Ultrasound assessment was with standard protocol
and descriptive report. Image quality assessed on a scale. Deep veins evaluated
for patency and evidence of thrombosis. Quality and calibre of the major superficial
veins, sites of division & major tributaries were recorded. Superficial leg vein quality
and diameter at reference points plus relevant variant anatomy were compared
between modalities. MRI studies were compared to the descriptive duplex reports
with a scale of utility.
Results: 20 patients. MRI image quality excellent in all but one where imaging was
corrupted by motion. All deep veins patient with no DVT. Vein diameters assessed
up to 20% smaller calibre on MRA (accounted for by the differences in technique supine with cuffs deflated for MRI, erect with tourniquets to aid venous distension
for ultrasound). MRA showed more superficial veins, more divisions and more large
perforating tributaries than ultrasound. MRA was judged more informative than the
descriptive ultrasound reports.
Conclusion: Lower limb MRA with blood pool contrast agent and steady state
imaging may obviate ultrasound in the assessment for vein bypass grafting.
B-200
15:21
MR-lymphangiography at 3.0 T: Correlation with lymphoscintigraphy
M. Notohamiprodjo, M. Weiss, R. Baumeister, T.F. Jakobs, C. Glaser, M.F. Reiser,
K.A. Herrmann; Munich/DE (mike.notohamiprodjo@med.uni-muenchen.de)
Purpose: To correlate the findings in contrast-enhanced MR-lymphangiography
(MRL) with lymphoscintigraphy for detection and visualization of pathologies of the
peripheral lymphatic system.
Methods and Materials: A total of 20 consecutive patients with various pathologies of the peripheral lymphatic system, including uni- or bilateral lymphedema,
lymphoceles and lymph-vessel-transplants were examined with a fat-saturated T1w3D-GRE-(FLASH)-sequence (TR3.76 ms/TE1.45 ms/FA30°/voxel-size 0.83 mm3)
after intracutaneous injection of Gd-DTPA on a 3.0 T-scanner (Magnetom VERIO).
Four anatomic levels were examined from the foot to the pelvis. Two radiologists
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Multicenter, double-blind, randomized, intraindividual crossover
comparison of gadobenate dimeglumine (MultiHance®) and gadopentetate
dimeglumine (Magnevist®) for MR angiography of the peripheral arteries
T. Leiner1, T. Le Maire2, S. Miller3, S. Thurnher4, A. Vanzulli5, J. Vymazal6,
M. Wasser7, M.A. Kirchin5, G. Pirovano8; 1Maastricht/NL, 2Eindhoven/NL,
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Tübingen/DE, 4Vienna/AT, 5Milan/IT, 6Prague/CZ, 7Leiden/NL,
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Princeton, NJ/US
Scientific Sessions
and one nuclear-physician evaluated the depiction of lymph-collectors, pattern
of drainage, number of visualized levels and lymph-nodes in consensus using
a 3-point scale. Conventional lymphoscintigraphy with a colloid-bound 99Tcmtracer served as standard of reference. Statistical analysis was performed using
intraclass-correlation.
Results: All MRL were well tolerated and diagnostic. Correlation between MRL and
lymphoscintigraphy was excellent (r=0.92). Normal and instant lymphatic drainage
was observed in unaffected extremities with both modalities shortly after contrast
application. Depiction of delayed drainage, lymph-transplants and lymphoceles was
overall concordant in both modalities. Reduced lymphatic-drainage in lymphoscintigraphy correlated with lymph-vessel ectasia in MRL (9/20 cases). In 5/20 cases
lymph-collectors were clearly visualized in MRL, whereas only hinted in lymphoscintigraphy. Depiction of inguinal lymph nodes was clearer in lymphoscintigraphy
in 4/20 cases. In one case inhomogeneous fat-saturation obscured detection of
diffuse drainage in MRL.
Conclusion: MRL and lymphoscintigraphy correlation is excellent. Lymphoscintigraphy seems to better visualize inguinal lymph-nodes, whereas MRL is superior to
depict lymph-collectors, anatomic details and morphological changes. MRL may
become a valuable tool for planning and monitoring the microsurgical therapy.
14:00 - 15:30
Room K
Computer Applications
SS 305
New trends in PACS and workstations
Moderators:
R.C. Sigal; Buc/FR
A. Simisker; Tartu/EE
B-201
14:00
A solution to find lost chest radiographs in PACS server
J. Morishita1, T. Hiwasa1, S. Katsuragawa2, Y. Sasaki3, Y. Sukenobu4, K. Doi5;
1
Fukuoka/JP, 2Kumamoto/JP, 3Morioka/JP, 4Suita/JP, 5Chicago, IL/US
(jm@shs.kyushu-u.ac.jp)
Purpose: To develop an automated search method by use of biological fingerprints,
i.e., some parts of chest radiographs, and image-matching technique in PACS
server. The assumption of this study is based on that radiology personnel will find
the occurrence of a missing current image in a specific patient folder before the
image reading.
Methods and Materials: We employed five biological fingerprints in a chest radiograph such as cardiac shadow, lung apex, the superior mediastinum, the right
lower lung, and a thoracic field. Each of the biological fingerprints was used as a
template for determination of the correlation value between the previous image
of the lost current image and each of all current images in a database including
36,210 patients. All images were acquired in the lung cancer screening program.
IRB approved and exempted from informed consent. Two hundred images were
selected randomly, and used hypothetically as lost images to examine the potential
usefulness of our method.
Results: 78.5% (157/200) of the lost images were correctly identified as the same
patient’s image from the large database. Moreover, it was possible to identify 89.0%
(178/200) with 21 additional lost images correctly, when previous images with the
top ten correlation index were examined. These results appear to be promising in
finding a patient with the lost images based on comparison with a large number
of images.
Conclusion: Our method by use of biological fingerprints and image-matching
technique would be a solution to find the lost chest radiographs automatically in
the PACS server.
B-202
14:09
Pseudonymization of DICOM data for clinical trials: A systematic review
A. Valentinitsch, F. Kampl, P. Peloschek, F. Kainberger; Vienna/AT
(alexander.valentinitsch@meduniwien.ac.at)
Purpose: To analyze the suitability of currently existing systems for de-identification
such as pseudonymization or anonymization of clinical data and the implementation in clinical trials.
Methods and Materials: A manual and electronic search of Medline and technical
databases was performed by using following keywords: de-identification, pseudonym, pseudonymization, anonymization, DICOM, clinical trials. Selected articles
were published from 1998 to 2008. The evaluation criteria towards de-identification
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architecture were: type of de-identification (pseudonymization or anonymization),
quantitative assessment of the encryption algorithm due to data security, development stage, DICOM data compatibility, PACS modularity, capability for clinical trials
and patient confidentiality according to the EU Directive (95/46/EC).
Results: Twenty-six articles fulfilled inclusion criteria: in 9 a pseudonymization
process is described, and 17 describe an anonymization process (predominantly
in form of k-anonymity). Only 3 studies describe possible model architectures of
pseudonymization, which were developed for medical research networks, but may
also be useful for clinical trials by considering the juridical aspects. Only one study
was designed to propose in clinical a pseudonymization model of cancer registry
that is in actual use in several German states. Unfortunately, only one study was
published to propose a de-identification scheme based on pseudonymization that
closely follows DICOM recommendation.
Conclusion: Few studies demonstrated a pseudonymization process suitable for
clinical trials. However, the studies about the reversible de-identification process
embedded in a clinical trial were not conclusive, because clinical trials predominantly
do not describe their de-identification methods due to patient confidentiality.
B-203
14:18
Web-based multi-lingual structured reporting
M. Fatehi1, A. Marashi2, A. Arjmand Shabestari1; 1Tehran/IR, 2Darmstadt/DE
(mansoor.fatehi@gmail.com)
Purpose: To introduce a web application, which provides multi-lingual structured
reporting services. The reports can be prepared in the language of the user, but
be printed in any other pre-defined language.
Methods and Materials: The concept of multi-lingual structured reporting by point
and click methods has been presented by the authors earlier, but this time a web
application is developed to provide the tree-structure, which consists of “regions”,
“blocks” and “items”. The interface is primarily designed in English language, but
it can be customized to any other language. The templates are constantly revised
to make them more applicable. Addition of a new language is possible through
webmaster, but after definition the new language will be available for both “interface” and “output”.
Results: Cardiac CT templates are now available for structured reporting in English
and German languages. The website requires sign up and currently provides free
reporting services to its users. The application relies on point and click methods,
and “regions of interest” for reporting are provided through a collection of mapped
images. The output report file can be printed or distributed as HTML file.
Conclusion: Web-based approach to structured reporting enables users of the
system to get the service from any location in the world and also get updated versions of SR platforms. In this way, since at the moment there is no international
consensus on standard radiology language, web-based solution will help developers
to update the list and content of their templates through time.
B-204
14:27
Compression of digital images in radiology: Results of a German
consensus conference
R.W.R. Loose1, R. Braunschweig2, E. Kotter3, P. Mildenberger4, R. Simmler1,
M. Wucherer1; 1Nuremberg/DE, 2Halle/DE, 3Freiburg/DE, 4Mainz/DE
(loose@klinikum-nuernberg.de)
Purpose: To find recommendations for “lossy” compression of digital radiological
DICOM images in Germany by means of a consensus conference. The compression
of digital radiological images was evaluated in many studies. Although the results
demonstrate full diagnostic image quality of modality dependent compression
between 1:5 and 1:200, there are only few clinical applications.
Methods and Materials: A consensus conference with approx. 80 interested participants (radiology, industry, physics, and organizations) without individual invitation
was organized by the working groups AGIT and APT of the German Roentgen
Society DRG to determine compression factors without loss of diagnostic image
quality for different anatomical regions of CT, CR/DR, MR, RF/XA examinations.
The consent level was specified on at least 66%.
Results: For individual modalities, the following compression factors were recommended: CT (brain) 1:5, CT (all other applications) 1:8, CR/DR (all applications
except mammography) 1:10, CR/DR (mammography) 1:15, MR (all applications)
1:7, RF/XA (fluoroscopy, DSA, cardiac angio) 1:6. The recommended compression
ratios are valid for JPEG and JPEG2000/Wavelet compressions.
Conclusion: The results may be understood as recommendations and indicate
upper limits of compression factors, where no reduction of diagnostic image quality
has to be expected. The results of the German consensus conference are similar
to actual national recommendations in Canada and England.
Scientific Sessions
B-205
14:36
Reconstruction of high-quality CTA from noisy cerebral CT perfusion data
E.J. Smit1, A.M. Mendrik1, A. Waaijer1, G. Bertolini2, E.-J. Vonken1,
B. van Ginneken1, M. Prokop1; 1Utrecht/NL, 2Padua/IT (ewoudsmit@gmail.com)
B-206
14:45
Ultrasound (US) and magnetic resonance (MR): Is fusion imaging the way
to the future of musculoskeletal imaging?
E. Silvestri1, L.M. Sconfienza2, F. Lacelli3, S. Pucci1, F. Paparo1, G. Garlaschi1;
1
Genova/IT, 2San Donato Milanese/IT, 3Pietra Ligure/IT
Purpose: US and MR are both valuable imaging techniques to study the musculoskeletal system. Nevertheless, each of them has several advantages and some
disadvantages. Their fusion with a new imaging software could represent a new
frontier in musculoskeletal radiology. The purpose of our paper is to present some
features of this new technique applied to the study of the hand.
Methods and Materials: 8 healthy volunteers underwent a MR scan of the hand (16
hands). T1-weighted sequences on axial, sagittal and coronal plans were acquired.
Registration between volunteers’ anatomy and their MR data was done by clicking
anatomic markers. Afterwards, these patients underwent a bilateral US scan of the
hand. The US system consists of a scanner integrated with a system that provides
the US image and its features such as the spatial dimension, orientation and probe
field of view. These data are provided by the US scanner by the network connection
and automatically updated at every change of position of the probe.
Results: The system permitted a right representation in size and orientation of the
MR images in real time during the US examination. There was a perfect correlation
between US and MR images, with a relevant anatomic adherence. Information
coming from MR scans was perfectly integrated with the US and readily available
to the radiologist.
Conclusion: Fusion imaging is a promising new technique in the study of musculoskeletal system in volunteers. However, further investigations are required to
understand if this method is valuable in daily clinical practice.
B-207
14:54
Multi-phase and multi-modality 3D visualization of CT and MR data sets
J. Fornaro, B. Marincek, T. Frauenfelder; Zurich/CH (juergenfornaro@gmail.com)
Purpose: With increasing spatial and temporal resolution of contrast-enhanced
multi-detector computed tomography (MD-CT) and magnetic resonance (MR)
imaging, acquisition of multiple well-timed data sets has become possible. Generally, these data sets are looked at individually or side by side. Often, it would be
beneficial to review two or more data sets simultaneously by superimposing them,
e.g. to relate pathology better appreciated in one data set to normal anatomy better
appreciated in another data set.
Methods and Materials: We implemented a two-step workflow for multi-volume
visualization in a tool running on a standard commercially available Windows computer: (1) The data sets were automatically registered using a mutual informationbased algorithm to compute the correct spatial alignment of the data sets, followed
by resampling to a common grid. (2) Concurrent direct multi-volume rendering of
the aligned data sets, where the user can adjust the color and opacity transfer
functions for the different data sets separately in real time.
B-208
15:03
Thin client technology for offsite expert reading of runoff CTA in a vascular
center
B.C. Meyer1, K.J. Wolf1, F.K. Wacker2; 1Berlin/DE, 2Baltimore, MD/US
(Bernhard.Meyer@Charite.de)
Purpose: To evaluate the benefits of thin client technology (TCT) for CTA reading
in an on-call situation.
Methods and Materials: A total of 20 CTA run-off data sets were read off-site in an
on-call situation using a thin client solution (VisageCS® ThinClient,Visageimaging)
and a digital subscriber line (6 Mbit/s). To assess the feasibility of using TCT by the
interventional radiologist on call at home, time from the initial phone call to study
availability on the client, and to final diagnosis were measured and compared to
the processing time in the hospital (1Gbit,LAN).
Results: DSL-based data transfer yielded an interactive experience with images
in diagnostic quality available within less than 1 minute. Time from the initial phone
call to study on screen ranged from 2:30 to 11 (median 6) minutes. The post processing time ranged from 5:30 to16:00 (median 12:30)minutes. The time from the
initial phone call to the final diagnosis given to the resident ranged from 12:30 to21
(median 15) minutes. There was no significant time difference for post processing
off-site and in the hospital (t-test, P 0.05). Off-site and on-site reading showed
100% agreement with regard to the therapeutic measures that were taken.
Conclusion: For vascular emergencies, CT angiography (CTA) has replaced
intra-arterial DSA in most cases. CTA data sets may comprise more than 3,000
images. In an on-call situation, however, data transfer and computing power can
be bottlenecks. With the thin client solution presented, heavy processing is done
at the server, and only the resulting screen content is transferred for reading.
Therefore, sophisticated post-processing can be performed on a basic laptop or
desktop computer.
B-209
15:12
Image interpretation with emerging handheld devices: A comparative
study of display performance
P. Mc Laughlin, C. Brennan, J. Coyle, K. O’Regan, S. Mc Williams,
A. Mc Garrigle, M. Maher; Cork/IE (mclaughlin.paddy@gmail.com)
Purpose: The potential role of handheld devices in the analysis of radiographic
images has been identified in the scientific literature. Image interpretation with these
handheld devices requires adequate display performance including sufficient detail
resolution and low contrast detectability.We aim to objectively compare the display
characteristics of a representative subset of handheld devices.
Methods and Materials: Using the Artinis contrast detail phantom type 2.0, 4
observers objectively scored the display performance of the Iphone (Apple), N73
cellphone (Nokia) and the Ipaq PDA (Hewlett Packard). Threshold contrast as a
function of object diameter was determined and the display performance of each
device was plotted on a contrast detail curve. As a reference, the display performance of a 0.8 and 3-Megapixel monochrome liquid crystal display was also
scored. CT images containing pulmonary nodules of size range 2-16 mm were
viewed and subjective reader confidence in nodule identification was recorded
using the visual analogue scale.
Results: Nodules greater than 7 mm were identified with 100% confidence in all
tested devices. Confidence for 7 mm nodule identification was greater for the
Iphone than other tested devices. Contrast detail curves varied widely among the
tested group. No significant interobserver variability existed p 0.001. The Iphone
had superior contrast detectability and detail resolution than other handhelds and
was comparable to that of the tested 0.8- Megapixel LCD Monitor.
Conclusion: We conclude that recent advances in technology have improved the
display performance of handheld devices such that their diagnostic efficacy may
soon approach that of 0.8 Megapixel LCD monitors.
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Purpose: Current techniques for reconstructing CT angiography (CTA) from CT
perfusion (CTP) data use single arterial phase (aCTP) or the temporal MIP (tMIP)
but such images suffer from the increased image noise in thin-section CTP data.
We developed and tested a technique that allows for reconstruction of high-quality
CTA from noisy cerebral CTP data.
Methods and Materials: We developed a novel method for reconstructing CTA
from CTP data that combines the advantages of tMIP (high vascular contrast) and
temporal mean (low image noise). This perfusion-derived CTA (pCTA) was tested on
17 patients with suspected subarachnoid haemorrhage who underwent CTP (80 kV,
150 mAs, 30 scans every 2s) and standard CTA with 64x0.625 mm collimation.
Standard CTA, aCTP, tMIP and pCTA were randomized and blindly presented to
an expert who was unaware of the techniques. All scans were scored on a 5-point
scale for arterial contrast, detail visibility, vascular noise and overall image quality.
Image noise was determined over a 100 mm2 homogenous ROI.
Results: pCTA yielded significantly superior visual scores for overall image quality
and vascular noise (p 0.05). Overall image quality with tMIP was significantly
superior to both CTA and aCTP. Detail visibility was similar to tMIP but significantly
better than CTA and aCTA. Arterial contrast was significantly higher than for standard CTA and similar to tMIP and aCTA. Image noise was significantly lowest on
pCTA and highest for aCTA.
Conclusion: Our CTA reconstruction algorithm appears superior to conventional
CTA of the brain and existing techniques for reconstructing CTA from CTP data.
Results: In a preliminary retrospective study, we successfully applied the described
technique to 10 clinical multi-phase MD-CT and MR data sets of the upper abdomen. The automatic registration of image data sets was reliable and time efficient
(mean time 5.5 seconds). User interaction for multi-volume rendering was similar
to single-volume rendering. Multi-volume rendering enabled concurrent and clearly
distinguishable visualization of upper abdominal pathology and anatomy of interest
in a single 3D image, without the need for tedious segmentation.
Conclusion: Multi-phase and multi-modality 3D visualization enhances the understanding of volumetric medical data.
Scientific Sessions
B-210
B-212
15:21
An autostereoscopic 3D display improves identification of intracranial
arteries in 3D models from time-of-flight MR-angiography
A. Abildgaard, A.K. Witwit, J.S. Karlsen, E.A. Jacobsen, B. Tennøe, G. Ringstad,
P. Due-Tønnessen; Oslo/NO (andreas.abildgaard@rikshospitalet.no)
Purpose: To evaluate whether the visual interpretation of 3D models from intracranial time-of-flight (TOF) MR-angiography (MRA) is improved by a new autostereoscopic 3D display.
Methods and Materials: Maximum intensity projection (MIP) and volume rendering
(VR) greyscale 3D models of intracranial arteries were created from ten anonymised
TOF MRA data sets. The models were displayed on a novel 20 inch autostereoscopic
3D display, which provides a true 3D perception without requiring specialized viewing
glasses. A predefined selection of 31 clinically relevant arteries or arterial segments
were digitally marked in the TOF source images. Each marking was displayed in
a separate 3D model as an overlying red dot. Three neuroradiologists viewed the
models in a randomized sequence, aiming to correctly identify the marked artery
in each model. A paired comparison was performed between arterial identifications
with the display operating either in 3D mode or in 2D mode.
Results: For all readers combined, 651 paired comparisons were done (314 MIP
and 337 VR). With MIP, 233 arterial markings (74 %) were identified correctly in
3D mode versus 179 (57%) in 2D mode. The odds ratio for correct identification
with 3D mode versus 2D mode was 2.17 (95% confidence interval 1.55-3.04,
P 0.001). With VR, 256 markings (75 %) were correctly identified using 3D mode
and 229 (68 %) using 2D (Odds ratio 1.49, 95% confidence interval 1.06-2.09, P
= 0.021).
Conclusion: Identification of intracranial arteries in 3D models from TOF MRA can
be improved by use of an autostereoscopic 3D display.
14:00 - 15:30
Room L/M
Neuro
SS 311
Functional magnetic resonance imaging
Moderators:
K. Aydin; Istanbul/TR
S. Sunaert; Leuven/BE
B-211
14:00
Compensatory brain activity of selective attention in patients with
postconcussion syndrome one month after minor head injury
M. Smits1, D.W.J. Dippel1, G.C. Houston2, P.A. Wielopolski1, P.J. Koudstaal1,
M.G.M. Hunink1, A. van der Lugt1; 1Rotterdam/NL, 2's Hertogenbosch/NL
(marion.smits@erasmusmc.nl)
Purpose: After minor head injury (MHI), postconcussive symptoms (PCS) such
as attention deficits frequently occur. It has been hypothesised that PCS are
caused by microstructural damage to the brain, causing a functional deficit. The
purpose of this study was to correlate functional MRI brain activation of selective
attention with PCS.
Methods and Materials: 21 patients 1 month after MHI and 12 healthy controls
(matched for age, gender and educational level) were scanned at 3 T. For functional
imaging, a T2*w GE-EPI sequence was used (TR/TE 2000/30 ms; acquisition
time 6:10 minutes), during which a Counting Stroop task was presented visually
to engage selective attention. Random effects group analyses were performed
using SPM2 (Wellcome department, London, UK), correlating brain activation with
the severity of PCS as evaluated with the Rivermead Postconcussion Symptoms
Questionnaire (RPSQ).
Results: Mean age was 28 years (range, 18-45 years), 20 were male. Median RPSQ
score was 8 (range, 0-46). In all subjects combined, significant (pcorrected 0.05) activation was seen in the dorsolateral and ventrolateral prefrontal cortex, the supplementary motor area, and in the inferior and superior parietal lobule and precuneus
(posterior parietal area). Increased activation (puncorrected 0.001), associated with
greater severity of PCS, was seen in the ventrolateral prefrontal cortex, anterior
and posterior cingulate cortex and precuneus (posterior parietal area).
Conclusion: Patients with PCS 1 month after MHI show increased activation during performance of a selective attention task. Such increased brain activity may be
considered a reflection of the brain’s compensatory response to - microstructural
- injury in patients with PCS.
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14:09
fMRI monitoring of mirror visual feedback therapy in phantom limb pain
G. Kasprian, S. Seidel, J. Furtner, M. Weber, T. Sycha, E. Auff, D. Prayer;
Vienna/AT (gregor.kasprian@meduniwien.ac.at)
Purpose: This fMRI study aims to assess the cortical activation patterns pre- and
post-neuromodulatory mirror visual feedback therapy (MVFT) in lower limb amputees with phantom limb pain (PLP).
Methods and Materials: Nine patients (mean age 50.8 years) with traumatic (n =
8) or ischemic (n = 1) etiology of lower limb amputation (level of right thigh-3, left
thigh-3, left calf-2, left hip-1) and 2 healthy controls underwent fMRI at 1.5 Tesla using
a BOLD sensitive T2*-weighted multislice gradient echo EPI sequence covering the
whole brain (TE = 50 ms, TR = 3616 ms, matrix = 96 x 78, 100 dynamics, acquisition
time 6 min). Activation (rhythmic flexion and extension of the existing and/or phantom
foot) was measured against rest, pre- and post-12 sessions of MVFT.
Results: Identical (n = 6), reduced (n = 4), and caudally shifted (n = 1) motor
representation of the missing lower extremity was found in the corresponding M1
area and ipsilateral supplementary motor area (SMA) activation was increased
(n = 5) compared to the motor/SMA representation of the intact contralateral leg.
In controls and patients (n = 8), primary motor activation patterns remained unchanged after MVFT. One out of three clinical responders showed signs of cortical
reorganization after therapy.
Conclusion: This is the first study to document the neurophysiologic basis of MVFT
in lower limb amputees and the utility of fMRI as clinical monitoring tool of therapy
response in drug resistant PLP.
B-213
14:18
Postoperative language deficits with resection of the supplemental motor
area: Correlation with preoperative functional MR imaging
J. Lyo, N. Petrovich, K.K. Peck, A.I. Holodny; New York, NY/US (jlyo@johnlyo.com)
Purpose: The supplemental motor area (SMA) is involved in higher order language
processing. Does pre-operative determination of SMA laterality with fMRI predict
postoperative speech deficits?
Methods and Materials: fMRI was performed on fifteen patients with lesions
involving the SMA (sparing Broca and Wernicke areas) prior to resection. fMRI
language paradigms were performed (verb generation, category generation, and
phonemic fluency), along with formal neuropsychologic testing before and after
surgery. fMRI was performed on 1.5 T or 3 T GE scanners using echo-planar imaging. SMA functional activity was quantified with AFNI using volumetric ROI on
bilateral SMA, with cross-correlation analysis p-value 0.001. Laterality index for
SMA activation = (Left - Right)/(Left + Right).
Results: Six of the fifteen patients with partial or complete resection of the SMA
developed speech deficits, from expressive language impairment to mutism and
global aphasia, and these patients had left lateralized SMA with ipsilateral resection.
All six demonstrated significant recovery of speech within 6 weeks. Two patients
had pre-existing language deficits, not significantly altered with surgery: one had
right lateralized SMA and contralateral resection; the other, left lateralized SMA
and ipsilateral resection. All patients with resection of the non-lateralized SMA did
not develop a language deficit (SMA was lateralized to the right in three, and left
in four of these patients).
Conclusion: Tumor resection of all or part of the fMRI-lateralized SMA resulted
in language deficits. Resection contralateral to the fMRI-lateralized SMA resulted
in no speech deficits.
B-214
14:27
Evaluation of language processing in fMRI at 7 T
N. Koschnicke, S. Maderwald, J.M. Theysohn, K. Großkurth, M.E. Ladd,
E.R. Gizewski; Essen/DE (nina.ko@gmx.de)
Purpose: fMRI is one of the most likely applications to benefit from high-field MRI.
It profits from the higher signal-to-noise ratio (SNR) and increased BOLD contrast
itself. To our knowledge, no one has yet evaluated this advantage at 7 T with a
focus on speech regions.
Methods and Materials: Ten right-handed volunteers were measured at both 1.5
and 7 T solving tasks (word generation and synonym detection test) with fMRI in
a block design fashion. An EPI sequence with short TE (28 ms at 7 T) and parallel
imaging (GRAPPA R = 3) was chosen. An 8-channel transmit/receive head coil
(Rapid Biomed, Germany) was used for image acquisition at 7 T. Statistical analyses
were performed using SPM 05.
Results: Cerebral areas involved in language processing, speech production, and
comprehension (Broca’s and Wernicke’s area) could be revealed using 7 T. One
volunteer revealed activation in both hemispheres which was not detected at 1.5
Scientific Sessions
B-215
14:36
Real-time fMRI biofeedback may improve chronic tinnitus:
Proof of principle
S. Haller1, R. Veit2; 1Basle/CH, 2Tübingen/DE (shaller@uhbs.ch)
Purpose: Tinnitus is accompanied by excess auditory activations. Transient
reduction of this activation via transcranial magnetic stimulation (TMS) may
reduce tinnitus. We tested the hypothesis that participants with chronic tinnitus
can learn to voluntarily reduce the auditory activation by means of real-time fMRI
biofeedback.
Methods and Materials: Four participants with chronic tinnitus were included
(preliminary results). First, the individual auditory cortex was determined in standard fMRI auditory block-design. Then, participants trained to voluntarily reduce
the auditory activation using real-time fMRI with visual biofeedback of the current
auditory activation. Tinnitus self-assessment was done before and after biofeedback training.
Results: Most participants successfully learned to voluntarily reduce auditory activation, which reduced the subjective tinnitus sensation in the majority of subjects.
Conclusion: These preliminary results prove the concept that voluntary reduction
of auditory activations by real-time biofeedback fMRI may reduce tinnitus. Optimized
training protocols might further improve the results.
B-216
14:45
The effect of glaucoma on the posterior visual pathway: A combined fMRI
and DTI study
Q. Zhang, Y.-T. Zhang, J. Zhang, W. Li; Tianjin/CN (zhangquan0912@163.com)
Purpose:To explore the abnormal changes of the visual cortex and bilateral optic
radiation in patients with glaucoma with fMRI and DTI.
Methods and Materials: A total of 16 patients with chronic angle-closure glaucoma
and without any diseases in the posterior visual pathway were recruited in this
study. Sixteen matched subjects were selected as control. Informed consent was
obtained from all patients and subjects. Block-designed fMRI was performed with
a 1.5 T MR scanner (TR/TE 2000/60 ms; Matrix 64 x 64; thickness 5 mm; slice gap
1 mm). Black and white check board and “+” were used as stimulus and control,
respectively; six control and five stimulus blocks ran alternately and every block
lasted for 20 s. Bilateral eyes in the two groups received stimulus individually. The
fMRI data were processed with SPM2. Different mappings between the two groups
were obtained with inter-group analysis. DTI was performed with 13 diffusion directions and B value of 1,000 s/mm2. FA values of bilateral optic radiation between the
two groups were evaluated with two-sample t-test.
Results:In the subjects, activated regions mainly included the primary visual cortex
and cuneus, lingual gyrus, middle gyrus of the occipital lobe, fusiform gyrus and
the inferior temporal gyrus. The activated extent and intensity of the visual cortex
decreased in patients when compared with the subjects, especially in the advanced
stage of glaucoma. The FA values in the bilateral optic radiation were obviously
decreased in the glaucoma than in the subjects.
Conclusion:The posterior visual pathway may be damaged by glaucoma, especially
in the advanced stage, and those damages of the posterior visual pathway can be
detected with fMRI and DTI.
B-217
14:54
Background MR gradient noise and non-auditory BOLD activations: A
data-driven perspective
S. Haller1, G. Homola2, C.F. Beckmann3, J. Bartsch2; 1Basle/CH, 2Würzburg/DE,
3
London/UK (shaller@uhbs.ch)
Purpose: The effect of echoplanar imaging (EPI) of acoustic background noise
on blood oxygenation level-dependent (BOLD) activations was investigated. Two
EPI pulse sequences were compared: (i) conventional EPI with a pulsating sound
component of typically 8-10 Hz, which is a potent physiological stimulus and (ii)
recently established continuous-sound EPI, which is perceived as less distractive
despite equivalent sound pressure level.
Methods and Materials: A total of 16 healthy subjects performed an established
demanding visual n-back working memory task. Using an exploratory data analysis
technique (tensorial probabilistic independent component analysis; tensor-PICA),
we studied the inter-session/within-subject response variation introduced by
continuous-sound versus conventional EPI acoustic background noise in addition
to temporal and spatial signal characteristics.
Results: The analysis revealed a task-related component associated with the established higher-level working memory and motor feedback response network, which
exhibited a significant 19% increase in its average effect size for the continuoussound as opposed to conventional EPI. Stimulus-related lower-level activations,
such as primary visual areas, were not modified.
Conclusion: EPI acoustic background noise influences much more than the auditory system per se. This analysis provides additional evidence for an enhancement
of task-related, extra-auditory BOLD activations by continuous-sound EPI due to
less distractive acoustic background gradient noise.
B-218
15:03
Potential impact of 32 channel receiver coil technology on functional
magnetic resonance imaging
J. Linn1, M. Burke2, K. Haegler1, V. Schöpf1, A.-M. Kleemann1, M. Wiesmann3,
J. Albrecht1; 1Munich/DE, 2Solingen/DE, 3Schwerin/DE (linn@nrad.de)
Purpose: Using finger tapping as the standard motor task for functional magnetic
resonance imaging (fMRI), we aimed to test the potential of a 32 channel coil for
performing fMRI compared to a standard 8 channel coil.
Methods and Materials: Brain activations were investigated in 14 healthy righthanded subjects performing finger tapping with the right index finger during two
experimental sessions, one with the 8 channel coil and one with the 32 channel
coil. The order of both sessions was pseudorandomized. The experiment was carried out based on a conventional block design and functional imaging data were
analyzed using SPM5. Additionally signal to noise and contrast to noise ratios
were compared.
Results: During both sessions activation on an FWE-corrected level was observed
in the motor cortex (precentral gyrus). A paired t-test comparing the effects of finger
tapping with the contrast “8 channel coil 32 channel coil" revealed no activations,
whereas the contrast "32 channel coil 8 channel coil" revealed activations in the
left hippocampus, left middle temporal gyrus, left middle and superior frontal gyrus,
left and right cerebellum, left and right temporal pole, left fusiform gyrus, and left
precentral gyrus (p 0.001 uncorrected for whole brain volume).
Conclusion: We demonstrated that the 32 channel coil indicated higher contrast
to noise ratios, and thus a more significant brain activation compared to the 8
channel coil. This technology has a potential impact on fMRI as well as on studies employing dynamic signal changes e.g. contrast enhanced angiography or
perfusion studies.
B-219
15:12
High-resolution functional MRI image using phase information
T. Yoneda, Y. Hiai, H. Arimura, Y. Kitajima, S. Tomiguchi, T. Hirai, Y. Yamashita;
Kumamoto/JP (tyoneda@kumamoto-u.ac.jp)
Purpose: The signal of phase image is quite sensitive to the subtle change in
blood oxygen level. We develop a new technique to create fMRI image using phase
information and examine a possibility of creating high-resolution fMRI image with
short scan time.
Methods and Materials: Hand grasping as activation is carried out for each of the
seven healthy volunteers. Each volunteer is scanned for three sets of activation
and rest state using PRESTO sequence (TR/TE = 31/50 ms, FA = 10 deg., FOV =
230 mm). We accumulate these data as dicom phase and magnitude files. Phase
difference-enhanced imaging (PADRE) technique, which enhances small values of
phase differences, calculates these data to create functional signal by subtracting
between the functional signal data of rest and activated states with the appropriate
threshold. Statistical test of signal appearance is carried out by setting ROI on the
activated area, which is defined by conventional fMRI image and inactivated area
symmetrically located about the central gyrus.
Results: We create a functional image whose matrix size is 256 x 256. Paired ttest shows clearly the difference between the activated area and inactivated area
(P 0.01) with appropriate threshold to create functional images. Additionally,
we can eliminate signal on the vessel by changing the filter size, which had been
already equipped to PADRE, to reduce false-positive signal due to the in-flow effect on fMRI image.
Conclusion: High-resolution fMRI image is created using phase information. We
confirm that functional image using phase information shows activated signal
precisely from the statistical point of view.
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T. The same corrected p value (p = 0.001) was used for all analyses. Furthermore,
the BOLD signal change was significantly higher at 7 T than at 1.5 T (factor 2 to 3),
while at the same time acquiring a voxel level at 7 T that was 5 to 6 times higher
compared to 1.5 T. A well-fitted response curve could be detected in all speech
areas at 7 T.
Conclusion: We detected speech areas consistently and reliably using whole-brain
fMRI at 7 T with good-quality response functions and, as expected, higher signal
compared to 1.5 T, even though using higher spatial resolution.
Scientific Sessions
B-220
15:21
Functional area reorganization in experimental spinal cord injury:
Functional magnetic resonance imaging study
N. Chen, K. LI, X. Wang; Beijing/CN (cnddcndd@yahoo.com)
Purpose: To study the characteristic of functional area plasticity after the spinal
cord injury in rat.
Methods and Materials: Ten SD rats of completed spinal cord injury (SCI) at T6
level were performed the fMRI studies which with the electrical stimulation of the
left forepaw based on a block design at 4 weeks and 8 weeks after injured, and
ten normal rats as control groups. The MR images were spatially normalized to the
Paxinos and Watson atlas. Quantitative cluster analysis was carried out to calculate
the volumes and centers of activation in brain structures.
Results: The activation was confined to the contralateral somatosensory cortex
(CSC) in normal animal and extensive activation such as ipsilateral thalamus and the
caudate putamen was found in injured groups. The average center of activation of the
CSC was significantly different between the normal and injured animals (P 0.01).
The average percentages of activation at CSC were no statistically significant between them. The global volumes of activation in the normal, 4 and 8 week injured
rats were 23p5, 59p13, and 61p21 mm3, respectively, and there was significant difference (P 0.01) between the normal and injured animals. The center of activation
and activation volume for the ipsilateral caudate putamen and the thalamus was
statistically different (P 0.01) between the 4 and 8 week post injury.
Conclusion: These studies suggest extensive and ongoing plasticity in SCI-injured
animals. The quantitative information could be important in objectively monitoring
the effects of various therapeutic interventions and rehabilitation program in SCI.
14:00 - 15:30
Room N/O
Preclinical applications
Moderators:
C. Pirich; Salzburg/AT
E.A. Schellenberger; Berlin/DE
14:00
Dynamic MRI assays of endothelial permeability for the differentiation of
tumors with high from tumors with low VEGF-activity
C.C. Cyran1, B. Sennino2, Y. Fu2, B. Chaopathomkul2, D.M. Shames2,
M.F. Wendland2, D.M. McDonald2, R.C. Brasch2; 1Munich/DE, 2San Francisco, CA/US
(clemens.cyran@med.uni-muenchen.de)
Purpose: To evaluate dynamic MRI assays of endothelial permeability for their
potential to differentiate tumors with high intrinsic vascular endothelial growth factor (VEGF) activity from tumors with low VEGF-activity by correlating MRI assays
of endothelial permeability with immunohistochemical measurements of VEGF on
a tumor-by-tumor basis.
Methods and Materials: Subcutaneous tumor xenografts were grown in athymic
rats (n=13) from two poorly differentiated, estrogen-receptor-negative human breast
cancer cell lines; MDA-MB-231 (n=5) with a high level of intrinsic VEGF-activity and
MDA-MB-435 (n=8) with a low level of intrinsic VEGF-activity. Dynamic contrastenhanced MRI was performed at 2.0T using the macromolecular contrast agent
albumin-(Gd-DTPA)27. Quantitative estimates of tumor microvessel permeability (KPS;
µl/min·100 cm3), based on a two-compartment kinetic model, were correlated with
area-density (%) measurements of VEGF-immunoreactivity on tumor sections.
Results: Tumor endothelial permeability, assayed as the endothelial transfer coefficient KPS, was significantly higher (p 0.03) in MDA-MB-231 tumors (KPS=58p30.9 µl/
min·100 cm3) than in MDA-MB-435 tumors (KPS=24p8.4 µl/min·100 cm3, p 0.05).
Correspondingly, VEGF area-density in MDA-MB-231 tumors was significantly
higher (27.3p2.2%) than in MDA-MB-435 human breast cancer xenografts
(10.5p0.5%, p 0.05). Individual measurements for the two groups did not overlap.
The correlation between KPS values and measurements of VEGF area-density was
significant (r=0.68, p 0.01).
Conclusion: Dynamic MRI assays of endothelial permeability have the potential to
non-invasively assess VEGF-activity in tumors and could be clinically applicable to
define the suitability of patients for VEGF-inhibiting anti-angiogenic drug therapy.
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Purpose: New relaxometry methods have recently been successfully applied to
monitor anti-vascular therapies in vivo. Classical anti-angiogenic treatment protocols
clearly differ from anti-vascular therapies with respect to the biological response of
the tumor tissue. The purpose of this study was therefore to evaluate a $R2* multiecho MR-Relaxometry sequence for early assessment of anti-angiogenic tumor
treatment effectiveness using the VEGF inhibitor bevacizumab (Avastin®).
Methods and Materials: A673 bearing nude mice were injected with bevacizumab
(n = 6) or saline as control, respectively (n = 6). MR imaging was performed before
and after 2 cycles (100 µg bevacizumab on day 0 and 3) of therapy (day 7). USPIOinduced changes (SHU 555 C) of $R2* were measured in regions of interest. The
VVF, as a known surrogate marker of the microvessel density (MVD), was calculated. The MVD was determined by immunohistochemistry and correlated with MRI
results. For statistical analysis an unpaired t-test was applied.
Results: Bevacizumab treatment resulted in a significant reduction of $R2* values
compared to the controls (bevacizumab: 10.47 p 0.78 s-1 vs. control: 17.91 p 2.63
s-1, p 0.01) accompanied by a significant decrease of the VVF by 33% (bevacizumab: 2.21 p 0.15% vs. control: 3.31 p 0.22%; p 0.01). The MVD confirmed the
MR results showing a 25% reduction after treatment (bevacizumab: 7.11 p 0.3 vs.
control: 9.45 p 0.38; p 0.05).
Conclusion: USPIO enhanced Multi-echo $R2* MR-Relaxometry allows an accurate and early assessment of anti-angiogenic tumor treatment and may thus be
exploited for clinical therapy monitoring.
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Effect of antiangiogenic therapy to the luciferase activity controlled by
a HSP70 and CMV promoter in combination with MRI imaging in a M21
tumor model
W. Hundt1, C.E. O’Connell-Rodwell2, D. Mayer2, S. Guccione2; 1Marburg/DE,
2
Stanford, CA/US (walter.hundt@web.de)
SS 306
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14:09
Multi-echo delta R2* MR-relaxometry for antiangiogenic tumor treatment
monitoring
J. Ring1, T. Persigehl1, S. Remmele2, W. Heindel1, H. Dahnke1, C. Bremer1;
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Münster/DE, 2Hamburg/DE (Janine.Ring@gmx.de)
B-223
Molecular Imaging
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Purpose: We investigated the effect of targeted gene therapy to the M21 tumor
cell line combining bioluminescence (BLI) and MRI imaging.
Methods and Materials: M21 transfected with a plasmid containing the hsp70 or
the CMV promoter fragment and the luciferase reporter gene were grown to a size
of 900 mm3. Five animals in each group were intravenously treated with a AvB3-NP/
RAF (-) complex every 72 hours. Bioluminescence and MRI were performed at set
time intervals. The MRI scan protocol was T1-wt-SEpCM, T2-wt-FSE, Diffusion-wtSTEAM-sequence, T2-time obtained on a 1.5-T-GE-MRI scanner.
Results: The size of the treated M21 tumors kept nearly constant during the treatment phase (837.8p133.4 versus 914.8p134.4 mm3). BLI showed that the luciferase
activity controlled by the CMV promoter decreased to 51.1p8.3%. Controlled by the
hsp70 promoter, the highest luciferase activity (4.4p0.3 fold) was seen after 24 hours.
The SNR value (T2-weighted images) of the tumors was 36.7p0.6 and dropped
down to 31.2p4.4 (p=0.004). At the beginning, the SNR value (T1-weighted images)
of the tumors after contrast medium application was 42.3p1.9 and dropped down
to 28.5p3.0 (p 0.001). In the treatment group, the diffusion coefficient increased
significantly under therapy (0.54p0.009 versus 0.66p0.05).
Conclusion: Targeted antiangiogenic therapy can induce luciferase activity under
the control of an hsp70 promoter. MRI showed a significant reduction of contrast
medium uptake and increase of the diffusion coefficient of the tumors.
B-224
14:27
Imaging of early vascular response to heavy ion irradiation by targeted
ultrasound
M. Palmowski1, J. Huppert2, P. Peschke2, P. Hauff3, M. Reinhardt3, M. Mäurer4,
W. Semmler2, F. Kiessling1; 1Aachen/DE, 2Heidelberg/DE, 3Berlin/DE, 4Erlangen/DE
(mpalmowski@ukaachen.de)
Purpose: Individualization of therapy regimen combining radiotherapy with antiangiogenic drugs demands for non invasive insights into the regulation of angiogenic
markers. While angiogenic marker expression after conventional radiotherapy
has been studied, little is known about their response to heavy ion therapy (HIT).
Thus, we investigated if molecular ultrasound can be used to intraindividually track
changes in the angiogenic marker expression after HIT.
Methods and Materials: Expression of ICAM-1 and of AvB3-Integrin in subcutaneous
AT-1 prostate cancers in rats treated with HIT was studied by molecular ultrasound
and by immunohistochemistry. For this purpose, cyanoacrylate microbubbles were
Scientific Sessions
B-225
14:36
MR imaging of lipoprotein metabolism with lipophilic USPIO at 3 T
H. Ittrich, O. Bruns, K. Peldschus, M. Kaul, U. Tromsdorf, R. Reimer, A. Koops,
U. Beisiegel, G. Adam; Hamburg/DE (k.peldschus@uke.uni-hamburg.de)
Purpose: To develop dynamic MRI methods for in vivo imaging of liver lipoprotein
uptake and disorders in metabolism via MRI.
Methods and Materials: New nanosomes were designed in vitro with a magnetic
iron oxide core (USPIO) coated by a lipid-lipoprotein layer. In vivo dynamic MRI using
a T2*w FFE was performed before, during, and after i.v. application of USPIO in
apolipoprotein E (ApoE) deficient and wildtype mice (WT, control) using a clinical 3 T
scanner with a small animal solenoid coil. R2* measurements were performed before
(ba) and after (pa) USPIO application using a fat-saturated multi-echo FFE. SNR in
vena cava, aorta, portal vein, and liver as well as R2* of the liver were measured.
Uptake kinetics and R2* in were tested for statistical significance (t-test, p 0.05)
and matched with histology (H&E, Prussian blue) and electron microscopy.
Results: In vivo measurements showed a two-phase exponential SNR decrease
after UPSIO application in order of vena cava, aorta, portal vein, and liver followed
as well as a stable SNR drop in the liver of WT (ba: 43.9 p 2.3, pa: 8.2 p 1.2). ApoE
deficient animals showed a significantly delayed and reduced SNR decline of the
liver (ba: 44.2 p 3.1, pa: 10.6 p 0.6; p 0.03). Correlating the R2* of WT showed a
significantly higher increase (ba: 76.3 p 3.4 sec-1, pa: 164.3 p 11.4 sec-1) compared
to ApoE mice (ba: 79.9 p 2.5 sec-1; pa: 114.7 p 5.1 sec-1, p 0.004). Corresponding to MR imaging histology and electron microscopy showed a predominantly
accumulation of nanosomes in hepatocytes, but not in Kupffer cells.
Conclusion: Liver uptake of USPIO-marked lipoproteins and defects in liver lipoprotein metabolism can be monitored and detected by real time MRI at a clinical
3 T MR system.
B-226
14:45
In vivo molecular imaging of thrombus formation
R.-J.J.H.M. Miserus, L. Prinzen, V.M. Herias, T.M. Hackeng,
M.A.M.J. van Zandvoort, M.J.A.P. Daemen, J.M.A. van Engelshoven,
S. Heeneman, M. Kooi; Maastricht/NL (rj.miserus@rad.unimaas.nl)
Purpose: Thrombus formation plays a central role in several cardiovascular diseases. During the early stages of thrombus formation, activated factor XIII cross-links
A2-antiplasmin to the fibrin network, increasing the resistance of thrombi against
thrombolysis. Therefore, early detection of thrombus formation is vital.
Methods and Materials: A bimodal contrast agent (CA) was synthesized by coupling gadolinium-DTPA and rhodamine to an A2-antiplasmin-based peptide. For the
control CA, a glutamine residue essential for cross-linking was replaced by alanine.
In vitro-generated thrombi were exposed to both CAs and imaged by MRI (1.5 T)
and two photon laser scanning microscopy (TPLSM). In vivo feasibility of the CA in
detecting early thrombus formation, specifically, was investigated in a mouse model
with MRI (7T using an inversion recovery turbo spin echo pulse sequence).
Results: In vitro-generated thrombi exposed to the A2-antiplasmin-based CA
showed hyperintense MR signal intensities at the thrombus edge. No hyperintense
signal was observed using the A2-antiplasmin-based CA in the presence of FXIII
inhibitor dansylcadaverine, nor when using the control CA. TPLSM demonstrated
that the A2-antiplasmin-based CA was bound to fibrin. In vivo CA administration
within seconds after inducing thrombus formation increased contrast-to-noise
ratios (CNR: 2.28 p 0.39, N = 6) at the site of thrombus formation compared to
the control CA (CNR: -0.14 p 0.55, P = 0.003, N = 6) and A2-antiplasmin-based
CA administration 24-48 hours after thrombus formation (CNR: 0.11 p 0.23, P =
0.006, N = 6).
Conclusion: A novel bimodal CA was developed, characterized and validated. Our
results showed that this bimodal CA enabled non-invasive in vivo MR visualization
of early thrombus formation.
B-227
14:54
Targeting MRP14: A novel approach for in vivo monitoring disease activity
in rheumatoid arthritis
M. Eisenblaetter1, T. Vogl1, P. van Lent2, J. Roth1, C. Bremer1; 1Münster/DE,
2
Nijmegen/NL (eisenblaetter@uni-muenster.de)
Purpose: Monitoring of early stages and of disease-activity in chronic rheumatoid
arthritis is frequently impossible using conventional imaging approaches. Activated
macrophages (M&) play a pivotal role in joint-inflammation and the expression of M&
associated myeloid related proteins (MRP) has been shown to be strictly correlated
with disease activity. The feasibility of MRP-Targeting using a MRP14-antibody
labelled for fluorescence reflectance imaging (FRI) could be shown previously. This
study was performed to assess the capabilities of MRP-targeting for monitoring
disease-activity in experimental rheumatoid arthritis.
Methods and Materials: Cy5.5 was either coupled to an MRP14-antibody or to
immunoglobulin G serving as control for non-specific label distribution. Arthritis
was induced in DBA/1 lacJ-mice by injection of bovine type-II-collagen at days 1
and 21. FRI was performed at day 26, 24 h after dye-injection and signal-to-noiseratios (SNR) were calculated. For correlation of imaging findings, clinical severity of
the disease was assessed using a three-point-scale (CS0 - no clinical symptoms;
CS2 - severe inflammation) and MRP-serum-levels were determined by ELISA.
Data were statistically analyzed using one-way-ANOVA.
Results: Mice presenting with equivalent clinical scoring of inflammation (CS2),
revealed an approximately 2-fold higher SNR after anti-MRP14-Cy5.5 injection
as compared to IGG-Cy5.5 (92.4 vs. 52.9; p 0.05). Mild clinical severity, proven
by lower MRP-serum-levels (CS0: 840 ng/ml; CS1: 1170 ng/ml; CS2: 2910 ng/ml)
correlated with lower anti-MRP14-Cy5.5-fluorescence in FRI (CS0: 39.4; CS1:
40.5; CS2: 92.4).
Conclusion: Anti-MRP-Cy5.5 combined with FRI allows sensitive and specific
detection of phagocyte-activity represented by MRP14-expression in vivo and can
therefore be regarded a suitable probe for inflammatory activity in arthritis.
B-228
15:03
MR imaging of magnetically labeled stem cells in cartilage defects
T.D. Henning, E.J. Sutton, R. Meier, S. Tavri, T.M. Link, H.E. Daldrup-Link;
San Francisco, CA/US (henningtd@gmail.com)
Purpose: To visualize Ferumoxides labeled human mesenchymal stem cells
(hMSC) in cartilage defects by MR imaging at 3 T.
Methods and Materials: hMSCs were labeled with Ferumoxides (100 µg Fe/ml) by
transfection with Lipofectin. Viability was assessed by trypan blue exclusion and iron
uptake was measured by spectrometry. 18 cartilage defects (3 mm) were created
in porcine cadaver knees. In these defects, 2.2*105 Ferumoxides labeled cells in
Surgifoam (Johnson&Johnson, n=6), 2.2 * 105 unlabeled cells in Surgifoam (n=6)
or plain scaffolds (n=6) were implanted. All specimen were imaged in a clinical 3 T
MR scanner, using T1SE, T2 FSE, SPGR and T2*-sequences. The signal intensity
of scaffolds and cartilage was quantified as SNR and the contrast between these
structures was quantified as CNR. Differences in between different scaffolds and
in between pulse sequences were evaluated for significance by ANOVA. Histology
of specimens was performed after MR imaging.
Results: Cellular contrast agent uptake was 13.2 pg Fe/cell. No impairment of cell
viability was found and histology documented cells in scaffolds. Signal intensity
of the scaffolds was significantly different (p 0.05) from surrounding cartilage
in all sequences. SPGR images showed the highest CNR of the labeled scaffold
versus cartilage (79.1 p 29.1). On all sequences, CNR values between cartilage
and transplants were higher for labeled cells compared to unlabeled cells and
scaffold only.
Conclusion: Implants with labeled hMSC showed a significantly higher CNR
from surrounding cartilage than unlabeled cells. Therefore, the presented labeling
protocol offers a simple and efficient technique for stem cell tracking using matrix
associated cartilage implantation.
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synthesized and linked to specific ligands. Accumulation of targeted microbubbbles
in tumors was quantified before and 36 h after HIT. Additionally, tumor vascularization was analyzed using high-frequency Doppler ultrasound.
Results: In tumors accumulation of targeted microbubbles was significantly higher
compared with non specific ones and could be inhibited competitively. Prior to
treatment, no difference in binding of AvB3-Integrin-specific or ICAM-1-specific
microbubbles was observed in treated and untreated animals. After irradiation,
however, as compared to untreated controls there was a significantly higher
binding of AvB3-Integrin-specific microbubbles and an enhanced binding of ICAM1-specific microbubbles. In both groups, a decrease in vascularisation occurred
during tumor growth but no significant difference was observed between irradiated
and non irradiated tumors.
Conclusion: HIT upregulates ICAM-1 and AvB3-Integrin expression in tumor neovasculature. Molecular ultrasound can indicate the regulation of these angiogenic
markers and thus helps to identify the optimal time point for the onset of antiangiogenic treatments after HIT in individualized therapy regimen.
Scientific Sessions
B-229
14:00 - 15:30
15:12
Somatic differentiation of magnetically labeled human embryonic stem cells
T.D. Henning, S.E. Boddington, S. Taubert, P. Jha, S. Tavri, H.E. Daldrup-Link;
San Francisco, CA/US (henningtd@gmail.com)
Purpose: To magnetically label human embryonic stem cells (hESC) with
FDA-approved ferumoxides and to investigate the impact on their differentiation
potential.
Methods and Materials: hESC were labeled with Ferumoxides (100 µg Fe/ml).
Viability was assessed by trypan blue staining. Contrast agent uptake was quantified by spectrometry. Intracellular iron deposition and cellular ultrastructure was
investigated by transmission electron microscopy. Labeled and unlabeled hESC
were examined for pluripotency by fluorescent staining for the markers SSEA-1,
SSEA-2, TRA-60 and TRA-81. Somatic differentiation in embryoid bodies was
quantified by RT-PCR for the markers hOCT4, hACTC1, hSOX1 and hAFP. Embryoid
bodies of unlabeled controls and labeled hESC (n=3) were imaged over the time
course of 21 days during undirected somatic differentiation. Imaging was performed
at 3 T using T1SE, T2SE and T2*GE-sequences and SNR were compared for
significant differences.
Results: Contrast agent uptake was 1.4 pg Fe/cell. No significant decrease in cell
viability was found (p 0.05). Electron microscopy showed cytoplasmic storage
of iron oxide-particles in lysosomes. Fluorescent microscopy confirmed retained
pluripotency of labeled cells. RT-PCR of embryoid bodies showed up to 189-fold
induction of somatic germ layer markers and a 7-fold decrease of the embryonic
marker. Embryoid bodies of labeled hESC showed a significant T2-effect on T1weighted and T2-weighted images and a significant T2*-effect on T2*-weighted
images (p 0.05). After somatic differentiation for 21 days, embryoid bodies still
showed significant contrast agent effects (p 0.05).
Conclusion: After labeling with Ferumoxides, hESC retain pluripotency and differentiation potential. A contrast agent effect persists after differentiation for at
least 21 days.
B-230
15:21
In vivo MR evaluation of effect of CCR2 antagonist on macrophage
migration
Y. Lee, J. Ryu, J. Sohn, H. Jang, J. Lee; Seoul/KR (chosai@hanmail.net)
Purpose: The main aim of this study is to evaluate the feasibility of in vivo MR
imaging for assessing the inhibition of chemoattractant activity by CCR2 antagonist
and pertussis toxin.
Methods and Materials: Cell motility was investigated as in vitro migration of cells
to MCP-1 mixed with Matrigel matrix on 4-well chamber slide. For in vivo evaluation,
experimental soft-tissue infection in 12 mice was induced by inoculation with a 5
X 107 colony-forming unit of Staphylococcus aureus into the left calf. After treating macrophges with PBS (negative control group), CCR2 antagonist (antagonist
group), and pertussis toxin (positive control group), iron oxide labeled macrophages
(RAW 293.7) were injected through the tail vein. The left calf of the mice was imaged on a 4.7 T MR unit on day 3. The changes in relative signal intensity (SI) and
the pattern of contrast enhancement (macrophage distribution) were analyzed and
compared with histopathologic findings.
Results: In migration test with chamber slide, macrophages treated with CCR2antagonist showed significantly decreased chemotatic migration compared to wild
type macrophages. On MR images 24 hours after administration of macrophage
labeled with iron oxide, the band-shaped lower SI zone was noted in the abscess
wall. MR Signal intensity of the abscess wall significantly decreased in antagonist
group than negative control group but increased than positive control group.
Conclusion: CCR2 antagonist can block the CCR2 on macrophage and decrease
the chemotactic activity of macrophage toward MCP-1. In vivo MR imaging successfully demonstrate the effect of CCR2 antagonist to macrophage migration.
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Pulmonary embolism and hypertension
Moderators:
G. Bastarrika; Pamplona/ES
D. Hahn; Würzburg/DE
B-231
14:00
Minimizing contrast medium (CM) doses by using 80 kVp 16-MDCT to
diagnose acute pulmonary embolism (PE) in patients with moderate to
severe renal impairment
M. Kristiansson, S. Wettemark, L. Nilsson, U. Nyman; Trelleborg/SE
(mattias.kristiansson@skane.se)
Purpose: To report on further CM dose reduction from 200 (ECR-abstract 2007) to
150 mg I/kg (25% reduction) relative CM doses in a 16-MDCT survey (28-56 gram
iodine, i.e. 400-800 mg I/kg in a 70 kg individual) by using 80 kVp, bolus tracking,
constant injection duration adapted to scan time and saline chaser.
Methods and Materials: A total of 89 (38-100 kg) and 50 (41-84 kg) consecutive
patients with suspected PE and estimated GFR 50 mL/min underwent 80 kVp
16-MDCT (350 reference effective mAs; Siemens CareDose) after injecting 200 mg
I/kg during 15 seconds (13.3 mg I/kg/s) and 150 mg I/kg during 12 seconds (12.5 mg
I/kg/s), respectively, with a maximum dose weight of 80 kg and combined with
bolus tracking (100 HU enhancement threshold, 5 second scan delay) and 50 mL
saline chaser. Mean density, image noise (1 standard deviation), contrast-to-noise
ratio (assuming 70 HU for a fresh clot) of the left main pulmonary and a lower lobe
segmental artery were calculated on 3 mm thick slices.
Results: The following median values (2.5-97.5 percentiles) were obtained in the
200/150 mg I/kg cohorts: CM dose 13.1/9.6 (8.2-16.0/6.4-12.8) gram iodine, density 351/353 (199-563/164-488), HU and CNR 12/11 (6-26)/(4-22); PE incidence
22%/16% and 6%/8% on subjectively suboptimal examinations, but none classified
as nondiagnostic. All values were within those reported for common 16-MDCT
protocols. None of the 111 patients with plasma creatinine follow-up within 1 week
experienced contrast-induced nephropathy (plasma creatinine rise r44 µmol/L).
Conclusion: In patients at risk of contrast-induced nephropathy 80 kVp-MDCT
may be performed with markedly reduced CM doses and preserved diagnostic
quality compared with reported 16-MDCT standards.
B-232
14:09
Does 80 kVp pulmonary CT angiography deliver sufficient image quality in
patients weighing up to 100 kg?
Z. Szucs-Farkas, T. Strautz, L. Kurmann, M.A. Patak, P. Vock, S.T. Schindera;
Berne/CH (zsolt.szuecs@insel.ch)
Purpose: To assess if diagnostic quality is sufficient with pulmonary CT angiography
(CTA) using 80 kVp in patients weighing up to 100 kg or a lower threshold of body
weight (BW) should be applied.
Methods and Materials: A total of 100 patients weighing less than 100 kg (range,
44-99 kg; mean, 70.6 kg) with suspected pulmonary embolism were examined with
CTA using 80 kVp and reference mAs of 150 after injecting 75 mL contrast medium
at 3 mL/s. Attenuation in the pulmonary arteries and noise were measured, and the
contrast-to-noise ratios (CNR) were calculated. Three radiologists independently
analyzed the overall image quality, the most distal detectable ramification of the
pulmonary vessels and the noise and arterial enhancement in each pulmonary
artery on a five-grade scale. Patients were grouped by BW into 6 groups (group
1: 0-50 kg BW; groups 2-6: 51-100 kg BW, decimally increasing). Quantitative and
qualitative image parameters between the groups were compared by the analysis
of variance and post-hoc tests.
Results: No significant difference was found in the measured image noise between
patient groups above 50 kg (P = 0.387-1.0). CNR in patients weighing 71-80, 81-90
and 91-100 kg did not differ significantly (P = 0.116-1.0). There was no significant
difference between all the patient groups in the subjective ranking of enhancement
(P = 0.165-0.605), detectable ramification of the pulmonary arteries (P = 0.656),
subjective grading of noise in the vessels and mediastinum (P = 0.063 and 0.094,
respectively) and overall image quality (P = 0.079).
Conclusion: An 80 kVp pulmonary CTA permits sufficient diagnostic image quality
in patients weighing up to 100 kg.
Scientific Sessions
B-233
14:18
MDCT angiography of the pulmonary arteries using very low dose (40 cc)
of highly concentrate contrast media
V. Schembri, S. Lenel, J. Lonjon, H. Vernhet, S. Aufort, B. Gallix, J.-M. Bruel;
Montpellier/FR (valentina.schembri@inwind.it)
B-234
14:27
Dual energy CT for the diagnosis of pulmonary embolism: CT angiography
versus iodine map
R.W. Bauer, M. Kerl, P. Weisser, H. Korkusuz, T.J. Vogl; Frankfurt a. Main/DE
(ralfwbauer@aol.com)
Purpose: To evaluate the correlation of CT angiographic findings and perfusion
defect as assessed with Dual Energy CT (DECT) in the diagnosis of pulmonary
embolism (PE).
Methods and Materials: 25 consecutive patients underwent DECT angiography
for suspected PE. Scan protocol was as follows: tube voltage/current on tube A
140 kV/70 mAs, on tube B 80 kV/297 mAs, collimation 14x1.2 mm, slice thickness
1.5 mm. CTA data were assessed for the presence of emboli by two experienced
readers in consensus. Based on the dual energy characteristic of iodine at the two
different X-ray spectra, a color-coded iodine distribution map of the lung parenchyma
was calculated. This map was assessed for emboli-typical wedge-shaped areas
of reduced iodine content, i.e., perfusion defects (PD), by another two readers in
consensus who were blinded to the CTA results. Correspondence of the results
was assessed by calculating sensitivity and specificity on a per-patient and persegment basis.
Results: 23 segments in 8 patients showed pulmonary embolism on CTA, of which
20 segments in 7 patients showed corresponding PD, representing an 88/87%
sensitivity and 94/99% specificity on a patient/vessel-based analysis. 3 segments
with no PD showed non-occlusive clot formation on CTA.
Conclusion: Areas of the lung parenchyma with reduced iodine content on DECT
showed good correlation to the presence of emboli in the respective vascular territory. Both the morphological correlate of suspected PE and its hemodynamic significance can be demonstrated with the data acquired with a single DECT scan.
B-235
14:36
Dual energy CT pulmonary angiography: Initial experience in 30 patients
with pulmonary arterial hypertension
N. Screaton, E.T.D. Hoey, N. Qureshi, V. Ganesh, B. Agrawal, A.D. Tasker,
D. Gopalan; Cambridge/UK (nicholas.screaton@papworth.nhs.uk)
Purpose: To identify dual energy CT (DECT) perfusion patterns in patients with
different causes of pulmonary arterial hypertension.
Methods and Materials: 30 consecutive patients with pulmonary hypertension
referred for CT pulmonary angiography underwent DECT angiography with the
following parameters: Tube A 140 kV, Tube B 80 kV, 500 ms rotation, pitch 0.5.
Fused gray-scale images were reconstructed (70% 140 kV, 30% 80 kV) with 1.5 mm
section thickness. Iodine distribution maps were generated using pulmonary blood
volume software and overlaid on the gray-scale image. Each case was analysed
by 2 cardiothoracic radiologists by consensus and assigned a predominant perfusion pattern according to a predetermined descriptive scale: normal perfusion,
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14:45
Computer-aided detection of pulmonary embolism at pulmonary CT
angiography: Can it improve sensitivity of inexperienced readers?
K.N. Blackmon1, C. Florin2, H. Lee1, L. Bogoni2, P. Kogos1, J. Koonce1,
R. Coursey1, P. Costello1, U.J. Schoepf1; 1Charleston, SC/US, 2Malvern, PA/US
(schoepf@musc.edu)
Purpose: To evaluate the effect of a computer-aided detection (CAD) prototype
on the sensitivity of novice readers for detection of pulmonary embolism (PE) at
pulmonary CT angiography (CTA).
Methods and Materials: Forty-one consecutive CTA examinations clinically identified as positive for PE and 43 consecutive CTA examinations initially identified as
negative were included. Studies were evaluated in a randomized, blinded fashion
by two independent inexperienced readers who marked all vessels containing PE.
After 3 months, all studies were reevaluated by the two inexperienced readers,
this time aided by the CAD prototype. A consensus read by two expert radiologists
served as the reference standard.
Results: Expert consensus revealed 294 PEs (20 central, 2 lobar, 264 segmental,
and 8 subsegmental) in 41 patients. Inexperienced readers’ initial reads had an
average sensitivity of 23.13% on a per-PE basis, which improved to 45.24% with
CAD (p 0.001). False positives increased from 0.52 to 0.81/case. Of note, the
sensitivity of the CAD prototype averaged 82.65% (5% central, 50% lobar, 90.15%
segmental, 37.5% subsegmental). On a per-patient basis sensitivity increased
12.2% (27.5/41 true positives without CAD and 32/41 true positives with CAD;
p 0.001) and false positives increased 1.75% with CAD (2/43 false positives
without CAD and 3.5/43 with CAD). With CAD, the number of false negative patients
was reduced from 15 to 10.
Conclusion: CAD significantly improves sensitivity of PE detection for inexperienced
readers with a small but appreciable increase in the rate of false positives. Thus,
CAD may improve clinical management of patients, e.g. in on-call situations.
B-237
14:54
Evaluation of stand-alone detection performance of a prototype pulmonary
emboli (PE) CAD system across multi-vendor and multi-center MDCT data
S. Lakare1, M. Dinesh2, S. Mansur2, D. Desai3, A. Luthra4, J. Schoepf5, M. Das6,
D. Naidich7, M. Salganicoff1; 1Malvern, PA/US, 2Bangalore/IN, 3Mumbai/IN,
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Pune/IN, 5Charleston, SC/US, 6Aachen/DE, 7New York, NY/US
(sarang.lakare@gmail.com)
Purpose: To evaluate the potential variability of detection accuracy of a prototype
PE-CAD system on MDCT cases acquired from institutions, scanner models/
vendors different than those used in the development.
Methods and Materials: The PE-CAD system was developed with cases primarily
acquired from scanners manufactured by Siemens. For this study, 73 new cases
were acquired from five hospitals across three continents, referred for CTPA to
rule-out PE. Group 1 (G1, N1 = 50) contained cases from scanners manufactured
by Siemens (Volume Zoom = 1; Sensation16 = 20; Sensation 64 = 11;Cardiac
Sensation 64 = 18) acquired at 3 sites, in US, Europe and Asia. Group 2 (G2,
N2 = 23) had cases from Philips scanners (Brilliance 40 = 11; Brilliance 64 = 12)
acquired at 2 Asian sites. G1 had 60 emboli; 54 in lobar/segmental/sub-segmental
(LSS) region. G2 had 40 emboli; 28 in LSS. The contrast uptake (pulmonary trunk)
varied from 100 - 500 HU (mean 375 HU).
Results: For G1, per-PE sensitivity was 91.7% for all PE and 92.6% for LSS PE;
average FP was 2.9/case. For G2, 87.5% for all PE; 89.3% for LSS PE; average
FP of 1.8/case. The per-PE sensitivity across all 73 cases was 90% for all PE and
91.5% for LSS PE with FP of 2.6/case (mean) and 2/case (median). For 7 cases
(10%) with normal ground-truth, our system had zero detections.
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Purpose: To compare very low dose of high-concentration iodine contrast media
and high dose of standard contrast media on attenuation and visualization of the
pulmonary arteries in thoracic MDCT angiography.
Methods and Materials: 190 patients referred to our department for suspected
acute pulmonary embolism underwent MDCT angiography either with 40 cc of
high-concentration iodine contrast media (400 mgr/l) followed by 40 cc of saline
solution (GROUP A), or with 120 cc of standard concentration iodine contrast media
(350 mgr/l) when imaging of the abdomen and pelvis was performed during the
same examination (GROUP B). In both groups, the scan delay was determined
using automatic bolus tracking system. Flow rate and scanning parameter were
identical in both groups. Quantitative analysis was made by region of interest
measurement in pulmonary arteries (main, lobar, segmental and sub-segmental
arteries) to compare the attenuation profiles of the two groups.
Results: The mean enhancement was 356 and 308 HU (p 0.05) for groups A and
B, respectively, in the main arteries; 343 and 298 HU (p 0.01) in the lobar arteries;
326 and 284 HU (p 0.05) in the segmental arteries; and 286 and 256 HU (p=0.08)
in the sub-segmental arteries. The mean attenuation of the first, second, third and
fourth-order arteries was 327 HU in group A and 286 HU in group B (p 0.03).
Conclusion: A very low dose of high iodine concentration contrast media significantly increase pulmonary arteries enhancement compared to standard MDCT
protocol.
peripheral wedge shaped defects, mottled dot like defects, fine lace like defects
and unclassifiable defects.
Results: 15 patients had chronic thromboembolic disease, 5 idiopathic pulmonary
hypertension, 3 pulmonary fibrosis, 3 congenital left to right shunt, 2 left heart
disease and 2 emphysema. Peripheral wedge shaped defects were seen in 12
patients with thromboembolic disease and none of the other groups. Mottled dot
like defects were seen in 4 patients with idiopathic pulmonary hypertension and 2
with congenital left to right shunt. Fine lace like defects were seen in all those with
pulmonary fibrosis. The remaining 9 patients had an unclassifiable pattern.
Conclusion: DECT perfusion patterns seem to correspond with expected pathoanatomic alterations of disease state. DECT appears most useful in those with
chronic thromboembolic and idiopathic pulmonary hypertension and may obviate the
need for ventilation/perfusion scinigraphy following validation in large scale trials.
Scientific Sessions
Conclusion: The prototype system showed uniformly high sensitivity and low FP
rate across scanners from diverse vendors and models, and different geographic
sites world-wide. The results provide important confirmation on the reliability of
such systems as an adjunct to primary reads in a routine clinical environment at
multiple institutions where acquisition devices may vary.
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15:03
Diagnostic accuracy of real-time MRI, MR perfusion imaging, MR
angiography and cardiac volumetric measurement in acute pulmonary
embolism compared with MDCT
M. Schlieter, S. Ley, T. Heye, H.-U. Kauczor, W. Hosch; Heidelberg/DE
(martin.schlieter@med.uni-heidelberg.de)
Purpose: To assess the diagnostic accuracy of MRI compared with the reference
standard MDCT for detecting acute pulmonary thromboembolism; to assess the
quantification of pulmonary blood flow and volume by contrast-enhanced dynamic
magnetic resonance imaging using a parallel imaging technique and to prove the
feasibility of MRI in the detection of acute pulmonary embolism (PE).
Methods and Materials: 36 patients with suspected PE were first examined with
CT and afterwards transferred to the MR unit. A MR protocol combining real-time
MRI using true fast imaging with steady-state precession, half Fourier single shot
fast spin echo, 3 D fast low angle shot, generalized autocalibrating partially parallel
acquisition technique (acceleration factor 2), volumetric interpolated breath-hold
examination and cardiac volumetric measurements were performed.
Results: PE was diagnosed in 24 of the 36 patients who completed the MR
protocol. Perfusion MR revealed significant differences in mean transit time and
time to peak values, relative regional pulmonary blood flow and relative regional
pulmonary perfusion of areas affected by PE. The sensitivities of real-time MRI,
MR angiography, MR perfusion imaging, and the combined protocol were 83, 75,
100, and 100%, respectively. The specificities were 96, 100, 89, and 91%. Cine MR
revealed a paradoxical movement of the interventricular septum in 4 cases.
Conclusion: The combined MR protocol for the detection of PE is reliable and
diagnostic equivalent in comparison to MDCT. MR perfusion imaging is sensitive
for the detection of pulmonary embolism, whereas real-time MRI and MR angiography are specific.
B-239
15:12
Contrast-enhanced MR imaging of pulmonary arteries: New imaging
strategies with a blood-pool contrast agent
M.R. Makowski1, A.J. Wiethoff1, A. Bell1, V. Parish1, R.M. Botnar1, M. Rohrer2,
R. Razavi1, T. Schaeffter1, G. Greil1; 1London/UK, 2Berlin/DE
(marcusmakowski@gmail.com)
Purpose: First-pass breathhold non-ECG-triggered 3D contrast-enhanced
magnetic-resonance angiography (CEMRA) is commonly used for the assessment of the pulmonary arteries. However, using conventional extracellular
contrast agents, image resolution is limited by time constraints and borders are
blurred due to vascular motion and insufficient breath holds. Pulmonary vascular
imaging using a respiratory-gated and ECG-triggered 3D contrast-enhanced IRprepulse sequence in combination with Gadofosveset (mean intravascular t1/2A
= 0.48 p 0.11 h) and 32-channel coil technology is introduced and compared to
breathhold 3D-CEMRA.
Methods and Materials: In eight subjects (29 p 6 yrs) with normal pulmonary
vasculature, CEMRA was performed on a 1.5 T clinical scanner (Philips Medical
Systems) using 32-channel cardiac coil for fast imaging (SENSE = 4) and optimal
coverage. Patients were investigated twice using gadopentetate dimeglumine
(day1, 0.10-0.17 mmol/kg), and gadofosveset trisodium (day 2, 0.03 mmol/kg,
Bayer-Schering Pharma AG). CEMRA as well as a respiratory navigator-gated and
ECG-triggered steady-state free-precession (SSFP) sequence with a T2-prepulse
was used. An IR-prepulse to suppress surrounding tissue signal was applied with
gadofosveset trisodium.
Results: Significantly (P 0.05) better results (mean p SD) were achieved for the
high-resolution navigator-gated and ECG-triggered 3D-IR-SSFP sequence using
gadofosveset with regard to CNR (153 p 24 vs 89 p 37), vessel length (186 p 28 mm
vs 136 p 42 mm) and vessel wall sharpness (47 p 5% vs 33 p 6%) compared to
3D-CEMRA using Gd-DTPA. Gadofosveset did not improve the image quality in the
3D-SSFP technique without IR compared to Gd-DTPA and 3D-CEMRA.
Conclusion: Pulmonary vascular imaging using a navigator-gated and ECGtriggered 3D-IR-SSFP sequence with gadofosveset and 32-channel-coil technology
yielded significantly higher morphologic detail compared to breathhold CEMRA
and 3D-SSFP without IR. This technique has the potential to improve diagnostic
imaging of the pulmonary vasculature.
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B-240
15:21
Mean pulmonary arterial pressure estimation by phase-contrast MR
imaging in patients with chronic thromboembolic pulmonary hypertension
(CTEPH) and correlation with simultaneous invasive pressure recordings:
First results
K.-F. Kreitner, R. Kunz, S.A.H. Herber, E. Mayer, C. Düber; Mainz/DE
(kfathome@gmx.de)
Purpose: To estimate mean pulmonary arterial pressure (mPAP) in patients with
CTEPH by analysing flow parameters of the pulmonary trunc derived from high
temporal resolution phase-contrast MR imaging (PC-MRI).
Methods and Materials: We prospectively examined 7 CTEPH patients with high
temporal resolution PC-MRI at 1.5 T (Magnetom Sonata ®, Siemens Medical
Solutions) with simultaneous invasive pressure recordings in the pulmonary trunc.
Imaging parameters for PC-MRI were as follows: TR = 10 msec, TE = 2.5 msec,
Flip = 15°, velocity encoding = 100 cm/sec, bandwidth = 977 Hz/pixel, 3 averages.
The parameters absolute and relative acceleration time ATa [mesc] and ATr [%],
peak of mean velocities MRV [cm/sec], and distensibility DIS [%] were evaluated
according to Proc. Intl Soc Mag Reson Med 2003; 11: 407, and were used to
compute mPAP with the following regression equation: mPAP-PC-MRI [mmHg] =
88.9- 0.29 * ATa - 1.1 * ATr - 0.38 * MFV - 0.16 * DIS.
Results: MPAP-MRI correlated very well with simultaneous invasive pressure
recordings in all patients (linear coefficient of determination R2 = 0.979, p 0.001,
median difference +2.0 mm Hg, range -1.9 - + 4.7 mm Hg).
Conclusion: Non-invasive mPAP-estimations are possible in CTEPH-patients by
means of high temporal resolution PC-MRI and correlate well with simultaneous
invasively measured values.
14:00 - 15:30
Room Q
Interventional Radiology
SS 309
Musculoskeletal interventions
Moderators:
A. Feydy; Paris/FR
A.L. Jacob; Basle/CH
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14:00
Percutaneous treatment of contained disk herniations: Comparison among
three techniques
S. Marini, S. Marcia, M. Marras, G. Mallarini; Cagliari/IT (stemarini@gmail.com)
Purpose: This study was to compare three different techniques employed for
percutaneous treatment of contained disk herniations in order to evaluate their
benefits and pitfalls.
Methods and Materials: In our study, we evaluated 747 consecutive patients by
using in 305 nucleoplasty (NP), in 261 percutaneous laser disk decompression
(PLDD) and in 181 mechanic decompression with Dekompressor device (DK).
We performed on all patients with local anaesthesia. We always used discography
before performing each procedure. For each patient, 1 week, 3 months, 6 months
and 12 months outcomes were assessed by their treating physicians and support
staff. Success was defined as a minimum 2-points reduction on a visual analog
pain scale.
Results: Overall success rate in pain reduction was 72 and 84% at 1 week and
12 months by using NP (prepost procedure VAS 4.03, p=0.001). Success rate
in pain reduction was 73 and 81%, for 1 week and 12 months by using PLDD
(prepost procedure VAS 3.87, p=0.001). Rate in pain reduction was 71 and 81%,
for 1 week and 12 months by using DK (prepost procedure VAS 3.94, p=0.001).
Before the treatment 77% were used to having analgesic, after the treatment only
28% patients required it.
Conclusion: Results of our data suggest that the use of NP, PLDD and DK for
treatment of contained disk herniations may be all optimal therapeutic options
showing high success rates. For their safety, efficacy and feasibility, all these
procedures for percutaneous treatment of contained disk herniations have a wide
application in clinical practice.
Scientific Sessions
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14:09
Purpose: To evaluate safety and efficacy of percutaneous intervertebral disk
decompression (PDD) in the reduction of discogenic pain associated with disk
herniation.
Methods and Materials: During the last 3 years, a total of 33 intervertebral discs
were treated with fluoroscopically guided PDD. Indications included cervicobrachialgia, sciatica with/without lumbago and intervertebral disc herniation confirmed in
MRI with no neurologic deficit. Diminished disk height was noted in 7/31 patients.
Pain was assessed with preoperative pressure discography. Under local anesthetic (Lidocaine Hydrochloric 1%, 20 cc) and Fluoroscopy, PDD was performed
with 17G Dekompressor, on positive discographies. Prophylactic antibiotics were
administrated. Clinical evaluation included immediate and delayed follow-up
studies of patient’s general condition and neurological status. An AVS scale on a
questionnaire adapted to Greek population helped assessing pain relief degree,
life quality and mobility improvement.
Results: Patients were prospectively followed for 24 months with respect to pain
reduction and mobility improvement. Comparing patients’ scores prior (mean
value 7.4 p 1.4 AVS units) and after (mean value 1.6 p 2.4 AVS units) treatment,
patients included in our study presented a mean decrease of 5.8 p 2.4 AVS units
(p b 0.001) on terms of life quality improvement and pain relief. No complication
was observed. Six out of 8 patients with minimum improvement had reduced disc
height. Pain reduction was significant in 26/31 patients (83.7%).
Conclusion: PDD seems to be an efficient and safe technique for the therapy of
intervertebral disc herniation. Discs with decreased height had partial pain relief.
Pressure discography is a useful tool. No complication was noticed.
B-243
14:18
Pathological change in lumbar discs of goat after computed tomographyguided percutaneous intradiscal ozone injection
Z. Lin1, S. Lin2, Y. Dai1, S. Ye1, Y. Huang1, G. Li1, C. Chen1; 1Fuzhou/CN, 2Fuan/CN
(ccy0105213599@126.com)
Purpose: To investigate the pathological change in lumbar discs of goat after CTguided percutaneous intradiscal ozone3 injection.
Methods and Materials: Under the guidance of CT, 3 ml ozone (50 µg/ml) was
injected into L4/5 and L5/6 intervertebral discs with 22G Chiba needle in six goats.
Conventional MRI scan (FSE T1WI and FSE T2WI) were performed after injection.
The goats were evenly divided into 3 groups, and were sacrificed for pathology one
week (group 1), one month (group 2) and two months (group 3), respectively, after
the procedure. After MRI examination, the specimens were observed macroscopically and microscopically.
Results: The findings of post-procedure scan: the air was distributed intra- and
para- discs on CT and MRI images. No serious behavior abnormalities were
observed in all animals. On FSE T2WI images of group 2 and group 3, the signal
intensity of nucleus pulposus were attenuated in 4 discs. In group 1, the matrix
of nucleus pulposus was slightly edema. In group 2 and group 3, the atrophy of
nucleus pulposus and extensive proliferation of collagenous fiber was found. Under
the electron microscope, the samples of groups 2 & 3 demonstrated that a large
number of cells were necrosis, the neucli were lysis, the oraganelle and glycogen
was decreased obviously.
Conclusion: CT-guided percutaneous intradiscal ozone injection can lead gradually
to atrophy and fibrosis of nucleus pulposus. It was a minimally invasive, safe and
effective treatment for the intervetebral disc herniation.
B-244
14:27
Percutaneous radiofrequency neurotomy is effective in the treatment of
lumbar facet joint syndrome
S. Marcia, S. Marini, M. Marras, G. Mallarini; Cagliari/IT (stemarini@gmail.com)
Purpose: Lumbar medial branch neurotomy has been applied in the treatment
of facet joint syndrome by means of percutaneous radiofrequency denervation
(RFD). The data so far available on its efficacy is still controversial because of the
differences in patient selection and surgical technique. The aim of this study was
to provide new evidence on the clinical outcome of this procedure.
Methods and Materials: A total of 45 patients (mean age 70.3 p 13.0) with chronic
low back pain due to facet joint syndrome were selected for RFD. The diagnosis
was confirmed by gadolinium MRI and local anesthetic injection close to the zygapophysial symptomatic joints. Electrical stimulation of the medial branch nerve
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14:36
Percutaneous vertebroplasty with or without endovascular embolisation in
vertebral haemangiomas: Analysis of 56 cases
N.K. Bodhey, A.K. Gupta, T.R. Kapilamoorthy, C. Kesavadas, H.S. Pendharkar,
S.N. Patro, A. Periakaruppan; Trivandrum/IN (narendrakb2001@yahoo.co.in)
Purpose: Vertebral haemangiomas are a major cause of nondiscal backache.
The aim is to study the efficacy of endovascular embolisation and vertebroplasty
and long-term results.
Methods and Materials: Sixty-two vertebral haemangiomas were treated in 56
patients (22 males, 34 females) with age between 13 and 75 years. Presentation
was only backache in 35, additional paraparesis in 15 and rest had paraplegia.
Those with significant neurodeficit had thecal compression on imaging. Surgical
intervention was also contemplated in 8 patients due to this compression. Selective endovascular embolisation was done in 49 patients with Polyvinyl-alcohol
particles. Vertebroplasty with bone cement was done in all patients through a bone
biopsy needle introduced under fluoroscopic guidance. The results were analysed
with respect to pain relief, reduction in analgesic usage and improvement in the
neurodeficit.
Results: Majority of the haemangiomas were located in the dorsolumbar region.
The filling of the vertebrae with bone cement ranged between 60 and 90%. There
was significant pain relief in those presenting with backache. Paraparesis due to
mild thecal compression was relieved due to shrinkage of the extradural soft tissue
in 15 patients. Improvement in the grade of weakness was seen in 3 out of 6 with
paraplegia, yet required surgical decompression for total relief. Procedure-related
complications of leaking bone cement compressing the thecal contents were seen
in 3 patients with deficient posterior cortex.
Conclusion: The haemangiomas require a combined therapy with embolisation
and vertebroplasty for effective strengthening of the vertebrae specially so when
a surgical adjunct is contemplated.
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14:45
Treatment of osteoporotic spine fractures with percutaneous
vertebroplasty: Influence on health-related quality of life, frequency of
adjacent fractures and prospective assessment of fracture healing
O.T. Ertl, R. Fessl, K. Bohndorf; Augsburg/DE (esr@oliverertl.de)
Purpose: We quantified the positive effects of percutaneous vertebroplasty on
health-related quality of life. We documented the occurence and location of adjacent
fractures and prospectively assessed the evolution of fracture edema.
Methods and Materials: A total of 67 osteoporotic spine fractures were treated in
48 patients. Pain intensity (VAS) was documented before and 1 day and 3 months
post-intervention. Health-related quality of life was measured using the SF 36
questionnaire and paired t-test. Fracture edema and frequency of adjacent fractures
were prospectively assesed in sequential pre- and post-treatment MRI.
Results: Vertebroplasy led to a significant reduction in pain level from VAS 7.1
before intervention to VAS 3.1 one day post-intervention. Health-related quality of
life concomitantly increased, as shown in particular by the SF 36 score for “bodily
pain” (12.4 vs. 53.7, P 0.001). After 3 months, 20 patients showed increasing pain
levels. The reason was given as either continuous decrease in vertebral height, new
osteoporotic fractures or coexistent disease. Fracture edema persisted in 36% of
treated vertebral bodies without being associated with increased pain levels. Among
the 23 new fractures observed, 12 were in the proximity of the treated vertebral
body, whereas 11 were distant.
Conclusion: Percutaneous vertebroplasy led to fast pain reduction and to a sustained increase in health-related quality of life. Persistent fracture edema after 3
months was seen in 1/3 of cases. There was no association with increased pain
levels. New fractures in the proximity of treated vertebral fractures did not occur
more frequently than elsewhere.
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Percutaneous intervertebral disc decompression: Prospective study for
pain evaluation
D.K. Filippiadis, D. Erginousakis, N. Ptohis, E. Brountzos, N.L. Kelekis,
A.D. Kelekis; Athens/GR (dfilippiadis@yahoo.gr)
area with measurement of impedance was also performed in order to determine the
proper site of intervention and to avoid motor nerve lesion. Clinical evaluation and
assessment of pain by means of a visual analog scale (VAS, 0-10) was performed
before, 1 week, 1 month, 6 months and 12 months after the RFD procedure.
Results: A total of 54 joints were treated in the 45 patients enrolled in the study.
Baseline pain VAS was 8.6 p 1.1, while 12 months after RFD was 5.6 p 2.1
(p 0.0001, Mann-Whitney test). Only 14% of patients reported no improvement
3 months after RFD, while 24% of patients were still on analgesic drugs (compared
with 100% before treatment). No side effects were reported.
Conclusion: Lumbar medial branch neurotomy by means of RFD is an effective and safe procedure in reducing chronic back pain in patients with facet joint
syndrome.
Scientific Sessions
B-248
14:54
Percutaneous cryoablation in bone painful metastases
D. Bartolucci1, M. Mammucari2, F. Massari2, S. Masala2, G. Simonetti2; 1Terni/IT,
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Rome/IT
Purpose: Approximately 70% of patients with cancer have evidence of metastatic
disease at death. Skeleton represents the most common site of tumor metastasis. Approximately 50% of metastases arise from one of these primary types of
cancer: breast, lung, prostate or melanoma. The aim of this study is to determine
the safety and effectiveness of percutaneous cryoablation in pain reduction, daily
life activities improvement and reduction in the use of analgesics for patients with
bone painful metastatic lesions.
Methods and Materials: We treated with percutaneous cryoablation, during a 17
months period, 27 patients (17 men, 10 women; age range, 38-72 years; mean age,
52 years) with one or more painful metastatic lesions involving bone, with positive
visual analogue scale (mean score: 7.8), who did not respond to conventional
radiation treatment or chemotherapy.
Results: Postprocedural evaluation confirmed reduction of the VAS (mean score:
3.9). Treated lesions were 1-9 cm in maximum diameter. There was a marked increased in activities of daily living and reduction in narcotics utilization. No serious
complications were observed in our study.
Conclusion: Painful bone metastasis commonly occurs in advanced cancer
patients. They are difficult to manage because of pain, reduction of mobility and
performance status. In secondary bone tumors, few patients are surgical candidates, and so current treatments are aimed to pain palliation. Standard treatments
include radiation therapy, chemotherapy and analgesics. Percutaneous cryoablation is a safe and effective method for palliation of pain due to metastatic disease
involving bone.
B-249
15:03
Percutaneous CT-guided radiofrequency ablation of osteoid osteoma with
multitined expandable electrodes
R. Cioni, E. Bozzi, L. Crocetti, V. Zampa, C. Bartolozzi; Pisa/IT
(elenabozzi@libero.it)
Purpose: To determine the feasibility, safety and effectiveness of percutaneous
CT-guided radiofrequency ablation (RFA) of osteoid osteoma (OO) with multitined
expandable electrodes.
Methods and Materials: Thirty-three patients (age 4-60 years) with single OO
(27 long bones, 2 vertebrae, 2 calcaneum, 2 hips) were enrolled in a prospective, single center, single-arm clinical trial. Diagnosis was obtained by clinical and
imaging findings in 29 patients and by CT-guided biopsy in 4 patients. CT-guided
RFA was performed under conscious sedation or nerve block anesthesia with a
150-200 W generator and expandable multitined electrodes (RITA Medical Systems). Distance from lesion to skin ranged from 1 cm to 9 cm (mean: 5.1 cm p2.5).
Follow-up period ranged 6-58 months (mean: 30 months p 15) and included MR
examinations and clinical visits performed 6 months after the procedure and at
12-month intervals thereafter.
Results: RF ablation was technically feasible in all 33 patients (technical success
100%). No major complications, in particular no skin burns, occurred. Pain relief
and complete ablation of the nidus, as shown by the 6-month MR, was achieved
in 29/33 OOs (primary effectiveness rate 88%). In 4 patients, recurrence of pain
and persistent contrast uptake of the nidus at MR were present. The OOs were
effectively re-treated by means of RFA (secondary clinical success 100%). No
recurrences were observed on follow-up.
Conclusion: Percutaneous CT-guided RFA of OO performed with multitined expandable electrodes is feasible and safe. It yields prompt pain relief and return to
normal activities in a high rate of patients with OO.
B-250
15:12
Percutaneous iliosacral screw placement using CT fluoroscopic guidance
R.-T. Hoffmann, T. Jakobs, C.G. Trumm, S. Piltz, T.K. Helmberger, M.F. Reiser;
Munich/DE (ralf-thorsten.hoffmann@med.uni-muenchen.de)
Purpose: The purpose of this prospective study was to evaluate feasibility, safety,
time consumption and short-term complications of CT-fluoroscopic guided pelvic
fracture fixation.
Methods and Materials: Within 42 months 48 patients were referred for unstable
fractures of the posterior pelvic ring. Fourteen out of 48 patients suffered from
bilateral fractures of sacrum or sacroiliac joint and in 34 of 48 patients screws were
placed in S1 and/or S2 to create rotational stiffness. Length of screws and exact
entry point was defined on CT. After small skin incision, K wires were placed into
sacral bone under CT fluoroscopic guidance using a surgical hammer. After exact
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placement of K-wires a surgical drill was used to make the placement of the canulated, self-drilling screws possible. After placing screws, control scan was performed
to prove exact position of the screws and to rule out early adverse events.
Results: Sufficient screw placement was possible in all patients. No treatment
related minor or major complications occurred. Time between the first CT-scan and
end of procedure was 24 minutes (18-48) in patients with the need of a single sided
treatment and 75 minutes (45-105) in patients with treatment of both sides.
Conclusion: The screw-fixation of unstable fractures of the posterior pelvic ring
under CT fluoroscopy is feasible with no significant complications. The exact visualization and ease of screw placement enables a significant reduction of treatment
duration and is therefore advantageous for heavily injured patients.
14:00 - 15:30
Room R
Cardiac
SS 303
Cardiomyopathies
Moderators:
F. Knollmann; Pittsburgh, PA/US
J.-P. Laissy; Paris/FR
B-251
14:00
Late gadolinium enhancement compared to histology of autoimmune
experimental myocarditis in an animal model
H. Korkusuz, P. Esters, N.-E.A. Nour-Eldin, E. Mbalisike, N. Naguib, T.J. Vogl;
Frankfurt a. Main/DE (huedayi.korkusuz@kgu.de)
Purpose: To study if a rat model of experimental autoimmune myocarditis (EAM)
can be verified by a clinical 1.5 T MR magnet and to investigate late gadolinium
enhancement (LGE) pattern in EAM.
Methods and Materials: A total of 10 male Lewis rats, aged 6-8 weeks were immunized with porcine cardiac myosine on days 1 and 7, while 10 animals served
as control. On day 21, the animals were investigated by cardiovascular magnetic
resonance imaging (CMR). CMR examination was performed by ECG-triggered
gradient-echo (GRE) sequences of beating heart and by turbo-spin-echo (TSE)
sequences of stagnant heart.
Results: In the experimental group, eight animals survived and developed myocarditis, while the control group animals were healthy. Only animals in the experimental
group (n = 8) revealed LGE after gadolinium injection. The mean percentage of late
enhancement area detected by GRE sequences was higher at reduced heart rate
(25.93% p 23.6; P 0.05) compared to the physiological heart rate (5.67% p 4.37,
P 0.05). At reduced heart rate, mean percentage area of LGE correlated highly
with the mean percentage of the histologic inflammation area (r = 0.80 to r = 0.87,
P 0.05). LGE was mainly located in the anterior and lateral left ventricular wall
and septum with a midwall to subepicardial accentuation.
Conclusion: EAM in the rat model is verifiable by clinical MR magnet and due to
high correlations between CMR examination results and histopathological findings,
the current animal model can provide the opportunity for further radiologic fundamental research. LGE in the anterior and lateral left ventricular wall with midwall
to subepicardial accentuation seems to be a typical pattern in EAM. Heart rate
appears to influence signal intensity of LGE in EAM.
B-252
14:09
Cardiac MRI in Alström syndrome
F. Corbetti1, P. Maffei1, S. Romano1, C. Lacognata1, G. Milan1, J. Marshall2;
1
Padova/IT, 2Bar Harbor, ME/US (corbf@libero.it)
Purpose: To present the first findings of cardiac MRI in Alström syndrome, a rare
genetic disorder characterized by metabolic disturbances, deafness, blindness and
fibrotic infiltration of multiple organs including heart, possibly resulting in dilated
cardiomiopathy.
Methods and Materials: 5 patients aged 26-41 yrs with Alström syndrome and
ALMS1 gene mutations (Chr. 2p13) underwent cardiac MRI using short axis SSFP
sequences and dedicated software for functional evaluation, black blood T1and
T2 sequences for tissue evaluation, and late enhancement sequences (LE) after
gadobutrol (0.2 mmol/kg) to detect fibrosis. Inversion time (TI) 5’, 10’ and 15’ after
contrast injection was assessed using a TI scout sequence and compared with
values obtained in 10 healthy subjects by T test.
Results: Left ventricular function was normal in 1 case, mildly depressed in 3 (EF
48-55%) due to slight diffuse hypokinesia, and severely depressed in 1 (EF 23%)
due to septal akynesia and severe hypokynesia of other segments. Black blood T1
Scientific Sessions
B-253
14:18
Prognostic value of cardiac magnetic resonance (CMR) morpho-functional
findings in young subject with clinical suspicion of arrhythmogenic right
ventricular dysplasia (ARVD)
A. Esposito, F. De Cobelli, E. Mancini, E. Belloni, S. Ravelli, R. Mellone,
V. Fisichella, A. Del Maschio; Milan/IT (esposito.antonio@hsr.it)
Purpose: ARVD is an important cause of sudden cardiac death (SCD) among
young athletes. CMR is the gold standard to identify the morpho-functional findings which are included in diagnostic criteria (McKenna criteria; MKc), whereas
the CMR’s potential prognostic role has been poorly investigated. The aim of the
present study was to explore the prognostic value of CMR findings in young patients
referred for a suspicion of ARVD.
Methods and Materials: A total of 38 patients (27 males, 11 females; age =
25.2 p 6.8 years) with a clinical ARVD suspicion underwent CMR at 1.5 T. Intracardiac electrophysiological study (EPS) was also performed in all patients. The
occurrence of major arrhythmic events (MAE) was monitored during a follow-up of
16.4 p 5.3 months after the CMR.
Results: Only 1/38 patients had sufficient MKc for ARVD diagnosis. The 38 patients were separated into three groups according to the morpho-functional criteria
identified at CMR: G1) absence of MKc; G2) up to 2 minor-MKc; G3) major-MKc or
more than 2 minor-MKc at CMR. The three groups did not differ for anthropometrics
and clinical features excepting age (G1 = 24 p 7;G2 = 25 p 7 G3 = 32 p 3 years;
P 0.05). None of the 25 subjects included in G1 had MAE during follow-up. Two
of 9 (22%) of G2 and 1/4 (25%) of G3 experienced MAE during follow-up.
Conclusion: All subjects without CMR diagnostic criteria for ARVD remained free
from MAE during the follow-up suggesting that a negative CMR could be considered
a favourable prognostic factor. The two patients of G2 who experienced MAE during
follow-up did not have sufficient criteria for ARVD diagnosis; this result suggests
the opportunity to submit to EPS all ARVD-suspected patients with an incompletely
negative CMR for MKc.
B-254
14:27
Cardiac and mediastinal involvement in Erdheim-Chester disease: CT and
MR findings
D.L. Touitou, A.-L. Brun, C. Beigelman-Aubry, J. Haroche, P. Cluzel, P.A. Grenier;
Paris/FR (dtouit@hotmail.com)
Purpose: To retrospectively review the cardiac and mediastinal findings at computed
tomography and magnetic resonance imaging in a large series of 32 patients with
biopsy-proven Erdheim-Chester disease.
Methods and Materials: Two chest radiologists reviewed in consensus thoracic
CT scans (n=32) and cardiac MDCT (n=25) and MR (n=18) scans of thirty-two
patients with Erdheim-Chester disease (21 men and 11 women; mean age 53.8
years, range 19-75).
Results: Circumferential periaortic infiltration was observed in 25 patients (78%).
Extension of periaortic infiltration affected supraaortic trunks in 21 patients (65%),
coronary arteries in 17 patients (51.5%), intercostal arteries in 8 patients (25%).
Perivascular coronary infiltration was always located around the right coronary
artery, less frequently around the left coronary artery (n=9). Nine patients (28%)
presented with abnormal infiltration of the right atrial wall and 5 patients (16%) with
severe narrowing of the right atrial lumen and superior vena cava stenosis. Pericardial thickening and/or effusion was observed in 20 cases (62%). Infiltration of the
posterior mediastinum was seen in 17 patients (53%) with contiguous thickening
of the subpleural space and pleural effusion and/or thickening predominant in the
right hemithorax in 15 patients.
Conclusion: Erdheim-Chester disease has a wide spectrum of cardiac and mediastinal manifestations. Infiltration of the right atrio-ventricular sulcus around the right
coronary artery, pseudo-tumoral infiltration of the right atrium wall associated with
periaortic and retrocrural space infiltrates are highly suggestive of the diagnosis.
B-255
14:36
Quantitative MRI in the detection of cardiac iron in patients with
thalassemia
J. Yamamura, R. Engelhardt, R. Grosse, J. Graessner, R. Fischer, G.E. Janka,
G. Adam; Hamburg/DE (j.yamamura@uke.uni-hamburg.de)
Purpose: Quantitative MRI methods (e.g., GRE-R2*) have been developed for
the measurement of cardiac iron. In a cross-sectional study in patients with betathalassemia (TM) and sickle-cell disease (SCD), we aimed to assess patients with
elevated R2* at risk of developing problems from cardiac iron toxicity.
Methods and Materials: In the short axis view, R2* was analyzed from signal
intensities by exponential fitting. Breathhold retrospective ECG-gating was used
on a 1.5 T imager (Symphony®, Siemens, Erlangen), acquiring data from nine
heartbeats with eight echo-times between 1.9 and 21.5 ms in end-diastole (TR =
223 ms, flip angle = 20°). The left ventricular function was assessed from 6 mm
short and long axis of cine series spanning the entire cardiac cycle (25 phases).
Liver iron concentration (LIC) was measured by SQUID biomagnetic liver susceptometry in 14 patients getting blood transfusions (TM: n = 11, SCD: n = 3, age: 17-43
y) and 3 normal subjects.
Results: In patients with TM, a median relaxation rate of R2* = 76 s-1 (range: 22-340
s-1) was determined with 7/11 patients having R2* values above the widely accepted
normal threshold of 50 s-1. Patients with SCD did not differ from normal (range: 27-38
s-1). A significant correlation between R2* and LIC was found (Spearman rank RS
= 0.56, P = 0.01). In one patient, a high R2* of 222 p 18 s-1 indicated a potential
risk for developing CHF, although the LIC was at an optimum value of 938 µg/g wet
weight and the LVEF of 58% was still normal (49%, before1 y).
Conclusion: Elevated cardiac iron levels as indicated by R2* were found in all of
our thalassemia patients older than 21 y, although severe levels (R2* 100 s-1)
were only found in patients older than 29 y.
B-256
14:45
Assessment of cardiac iron and right ventricular function by GRE-MRI in
patients with thalassemia and sickle cell disease
J. Yamamura1, R. Engelhardt1, R. Grosse1, J. Graessner1, G. Kurio2, T. Mir1,
R. Fischer1, G.E. Janka1, G. Adam1; 1Hamburg/DE, 2Oakland, CA/US
(j.yamamura@uke.uni-hamburg.de)
Purpose: The aim was to evaluate the RV function (RVEF) and the cardiac iron
in patients with thalassaemia major/intermedia (TM/TI) and sickle-cell disease
(SCD).
Methods and Materials: In 9 splenectomized patients (4TM, 4TI, 1SCD: 24-43 y),
5 SCD patients (19-24 y) and 16 TM patients (11-32 y), the R2* was determined
from short-axis slices. Breathhold retrospective ECG gating was used on a 1.5 T
imager (Symphony®, Siemens) acquiring data from nine heartbeats with eight
echo times between 1.9 and 21.5 ms in end diastole (TR = 223 ms, flip angle =
20°). LV function was assessed from 6 mm short and long axis slices (25 phases).
RVEF was estimated from LV stroke volume and RV end-diastolic volume. The left
interventricular curvature ratio (LVCR) was derived by delineating the circular midsystolic LV shapes between RV junction points. RVEF was related to RV systolic
pressure (RVSP) and N-terminal pro-brain natriuretic peptide (NT-proBNP).
Results: Cardiac-R2* above the normal threshold of 50 s-1 were determined in 5/10
splenectomized patients and in 6/16 TM patients. Patients with SCD did not differ
from the normal (range: 29-33 s-1). The LVCR was determined between 0.6 and
0.9. Only in splenectomized patients, there was a decreased LVCR of 30 mmHg
indicating pulmonary hypertension. LVEF and RVEF were normal. Only in two
patients with extreme NT-proBNP levels ( 1,000), a reduced RVEF of 46 % at
still normal LVEF was detected.
Conclusion: Although normal LV function was found in nearly all of our thalassemia and sickle cell patients, we detected signs of pulmonary hypertension with
the interventricular curvature ratio, especially in older splenectomized patients
independent of their cardiac iron load.
B-257
14:54
Magnetic resonance (MR) evaluation of myocardial iron storage and left
ventricle ejection fraction (LVEF) in patients with thalassemia major (TM)
C. Ottonello1, F. Secchi1, G.D.E. Papini1, A. Giardino1, C. Turchetti1, A. Ciancio2,
A. Fragasso2, A. Aliprandi1, F. Sardanelli1; 1Milan/IT, 2Matera/IT (ottonello@seram.org)
Purpose: To evaluate myocardial iron storage and LVEF in patients with TM.
Methods and Materials: Thirty patients with TM (age 30p7 years) treated with longterm desferoxamine (n=20), deferiprone (n=4), or both (n=6) underwent 1.5-T MR
imaging with dual-echo T2*-weighted 4-chambers long-axis fast field echo sequence
(TR/TE1/TE2=12/4.6/9.2 ms). For each patient, we measured signal intensity (SI)
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and T2 images were unremarkable. On LE images, 2/3 pts with mildly impaired EF
showed slight midwall and/or transmural LE involving 1 and 2 segments; diffuse
midwall and transmural LE was found in the case with severe ventricular dysfunction.
TI values at 5’, 10’, 15’ were lower than in control group (133.7p7.5 vs 185.5p21.9
p 0.000; 164p13 vs 212.4p17.3 p 0.000; 180.2p14.3 vs 227.3p18.9 p 0.001)
even in patients without visual evidence of LE.
Conclusion: Cardiac MRI allows accurate evaluation of function and detection
of fibrosis in Alström syndrome. Reduced TI values might indicate microscopic
fibrosis in absence of visual LE.
Scientific Sessions
for three ROI placed in basal, middle, and apical interventricular septum. Myocardial
T2* was calculated using the following formula: T2* =-$TE/ln[SI (TE2)/SI (TE1)]. A
mean myocardial T2* 20 ms was considered as an iron storage. LVEF was obtained
from standard short-axis cine true-FISP sequences. Serum ferritin concentration
was measured and the mean value of the previous 12 months was considered.
Spearman correlation and Mann-Whitney test were used.
Results: Myocardial T2* was 26.0p10.1 ms; LVEF was 56p7%; serum ferritin concentration ranged within 321-4.910 ng/ml (median 869 ng/ml). Out of 30 patients, 10
had myocardial T2* 20 ms. Mean serum ferritin concentration was 2.458p1.660 ng/
ml for the 10 patients with myocardial T2* 20 ms and 1.259p930 ng/ml for the
20 patients with myocardial T2* r20 ms (p=0.082). The Spearman coefficient
between T2* and serum ferritin concentration was -0.329 (p=0.076), that between
T2* and LVEF -0.005 (p=0.979), that between serum ferritin concentration and
LVEF -0.453 (p=0.012).
Conclusion: Despite long-term iron-chelating therapy, about one-third of TM patients
showed abnormal myocardial T2* values. While there was no correlation between
T2* and LVEF, a significant correlation was found between serum ferritin concentration and LVEF and a borderline correlation between T2* and SFC.
B-258
15:03
Effect of enzyme replace therapy on patients with Anderson-Fabry
disease: A three years follow-up study assessed by MRI
M. Imbriaco, A. Pisani, B. Cianciaruso, E. Capuano, M. Fusari, G. Avitabile,
M. Marmo, M. Salvatore; Naples/IT (mimbriaco@hotmail.com)
Purpose: Anderson-Fabry (AF) is a multisystem X-linked disorder of lysosomal
metabolism associated with left ventricular (LV) hypertrophy. This study evaluated
the effects of enzyme replace therapy (ERT) on LV function and myocardial signal
intensity, assessed by MRI, in patients with AF, after 3-years of ERT.
Methods and Materials: 13 patients with AF (10 men/3 women, mean age: 33p10
years) underwent MRI at baseline (study 1) and after 3-years of ERT (study 2) with
recombinant a-galactosidase-A. MR studies were performed using a breath-holding
T2 weighted multi-echo TSE sequence with four different echo times, to obtain images of the 4-chamber horizontal long-axis plane for myocardial T2 relaxation time
(MT2RT) measurements. 3D balanced turbo field echo sequences were obtained
for evaluation of LV mass and ejection fraction (LVEF).
Results: No differences were observed in LVEF between study 1 and 2 (65p3 vs
66p5% p: n.s). A significant decrease in LV mass, was observed between study
1 (189p58 g) and 2 (152p45 g), (p 0.001). There was a significant reduction in
LV wall thickness between study 1 and 2 (16p4 vs 14p4 mm, p 0.001). A significant reduction in MT2RT was observed between study 1 and 2 (p 0.001) in all
myocardial regions (inter-ventricular septum 79p6 vs 64p9 msec, apex 78p10 vs
63p10 msec and lateral wall 80p8 vs 64p16 msec).
Conclusion: In patients with AF, there is a significant regression in cardiac hypertrophy, with a reduction in MT2RT after 3-years of ERT. Long term therapy with
A-galactosidase-A is effective for treatment of these patients, significantly improving
overall cardiac performance.
B-259
15:12
Myocardial hemosiderosis: Comparison of three methods for the
construction of myocardial T2* color parametric maps using data obtained
directly from a research PACS system
T.G. Maris1, K. Karolemeas2, K. Pagonidis1, N. Papanikolaou1, A.H. Karantanas1;
1
Iraklion/GR, 2Athens/GR (kpagonidis@yahoo.de)
Purpose: To compare three methods for the calculation of myocardial T2* values
assessed by means of quantitative MRI (T2*-qMRI) utilizing image data obtained
directly by a research PACS system.
Methods and Materials: Myocardial T2* values were calculated in 40 thalassemic
patients (mean age: 27 p 3.3 yrs, median age: 25.7 yrs) and 20 normal subjects on
a 1.5 T MRI system using an ECG-gated breathhold short axis 2D single-slice multi
echo (12 echoes) gradient echo (MEGRE) sequence with parameters: TR/TE1/
TE12/FA 180/2.4/28.9 ms/25o in end diastolic phase. T2* color image maps were
reconstructed using : (a) a commercially available, (b) a conventional linear and (c)
a weighted linear regression fitting algorithm utilizing post-proceassing tools of a
research PACS system. Liver iron concentration (LIC) was estimated non-invasively
using Yves Gandon's (Rennes University, France) methodology. Myocardial T2*
values were correlated with LIC and serum ferritin concentration (SFC) using all
methods. The methods were compared using Bland Altman (BA) tests.
Results: Differences of myocardial mean T2* values between patients and normal
subjects were considered to be extremely significant (t = 22.25, P 0.0001) with
all the methods. Myocardial T2* values were not correlated with LIC or SFC for all
methods. Method (a) showed increased variability when compared with methods
S196
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(b): [mean:3.7 ms, 95% range: 6.5 ms] and (c): [mean: 2.8 ms, 95% range: 9.2 ms]
using the BA test. Method (c) showed the best mean %CV (7.6%) as compared to
methods (b) (12%) and (a) (19%).
Conclusion: T2*, as assessed using color T2* parametric maps and weighted
regression analysis methods, seems to be a valuable means for an easy and
precise evaluation of myocardial hemosiderosis.
B-260
15:21
Fatty foci in the myocardium of patients with tuberous sclerosis complex:
A unique finding on CT
M.E.A.P. Adriaensen1, C. Schaefer-Prokop2, D.A.C. Duyndam2, B.A. Zonnenberg1,
M. Prokop1; 1Utrecht/NL, 2Amsterdam/NL (miraude@gmail.com)
Purpose: On abdominal CT performed for monitoring renal angiomyolipomas in
patients with tuberous sclerosis complex (TSC), we had frequently noticed focal
areas of fat within the myocardium. This case-control study examines frequency and
morphologic characteristics of focal fatty foci in the myocardium of TSC-patients.
Methods and Materials: We included 55 TSC-patients with a mean age of 34 years
(range 12 to 73 years; 22 males) in whom a CT was available that included at least
the basal portions of the heart. Fifty-five age- and sex-matched controls without TSC
were selected from our CT-database. We reviewed all scans for the presence of wellcircumscribed foci of pure fat density in the depicted portions of the myocardium. We
used descriptive statistics and a chi-square-test for case-control comparison.
Results: CT demonstrated foci of fat density within the myocardium in 35/55
TSC-patients (64%). Foci were located in the interventricular septum, left ventricle
wall, right ventricle wall, and papillary muscles. Size varied between 3x1 mm and
62x31 mm. Multiple lesions were seen in 19 patients. In the control group only one
lesion with fat density was found (1/55; 2%; p 0.001). Its characteristics differed
from those of TSC patients: linear shape and subendocardial location in the left
ventricular wall were suggestive of prior myocardial infarction.
Conclusion: Despite incomplete depiction of the heart with CT, the majority of TSCpatients demonstrated well-circumscribed foci of pure fat density in the myocardium
that were not present in age-and sex-matched controls. This suggests that such
fatty foci may be a new characteristic of TSC.
Scientific Sessions
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SS 611
Neuro
Tumors
(p. 210)
11:30
SS 601b
GI Tract
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cancer
(p. 212)
SY 2
Bracco
Satellite
Symposium
(p. 523)
SS 609b
Interventional
Radiology
Carotid and
intracranial
interventions
(p. 214)
SS 603b
Cardiac
Myocardial
perfusion
(p. 216)
WS 621
Image-Guided
Breast Biopsy:
How to do it
WS 624
Functional
Imaging of
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How to do it
Hands-on
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WS 622
Experience
Vascular
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Using
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11:30
12:00
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SY 6
Hitachi
Satellite
Symposium
(p. 524)
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SS 711
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Cardiac
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15:00
15:30
15:30
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Saturday
10:00
Scientific Sessions
10:30 - 12:00
Room B
SS 610
Hip and muscle
Moderators:
E. Belloch; Alzira/ES
C. Czerny; Vienna/AT
10:30
Location of femoral head asphericity by magnet resonance arthography:
Do normal radiographs exclude femoro-acetabular impingement?
M. Dudda, T.C. Mamisch, C.E. Albers, K.A. Siebenrock, S. Werlen, M. Beck;
Berne/CH (marcel.dudda@rub.de)
Purpose: Asphericity of the femoral head neck junction is one cause for femoroacetabular impingement (FAI) of the hip and is often underestimated on conventional
radiographs. The aim was to analyze the appearance of the morphology of the
proximal femur, comparing the radial sequences of magnet resonance arthrography
(MRA) and standard x-rays.
Methods and Materials: A total of 55 hips of 148 patients, who underwent a surgical dislocation of the hip were analysed. The alpha angle and height of asphericity
were measured in 14 positions using radial sequences of MRA. MRI protocol with
radial proton density weighted (PDW) sequences (TR 2000, TE 15, 260 x 260 mm
field of view, 266 x 512 matrix, 4 mm section thickness, 16 slices, 4 min 43 sec)
were orientated along the axis of the femoral neck. Separation into four groups
was done with respect to the appearance of an aspheric head neck junction on ap
pelvic and lateral cross table radiographs: group.i. : no radiographic signs of FAI;
group II: only on the cross table view; group III: only on the ap view; group IV: with
signs of FAI in both ap and cross table views.
Results: In all groups, an increased alpha angle and asphericity were found in
the anterosuperior area of the head neck junction. In group III, additionally there
was an asphericity inferior.
Conclusion: Even when conventional radiographs were normal, an increased
alpha angle indicating asphericity was present. Without use of radial sequences
in MRA, FAI would be missed in symptomatic patients. Normal radiographs did not
exclude asphericities of the proximal femur.
B-262
10:39
MR imaging in the diagnosis of labral and cartilage hip lesions in 43
patients with femoroacetabular impingement syndrome and surgical
correlation
G.E. Zamora, G. Delgado, E. Bosch; Santiago/CL
Purpose: Classically, MR arthrography has been used to diagnose labral and chondral pathology in patients with clinical diagnosis of femoroacetabular impingement
syndrome. The purpose of our study is to assess the effectiveness of MR imaging
in the evaluation of acetabular labrum and articular cartilage in comparison with
arthroscopy findings.
Methods and Materials: We reviewed, retrospectively, the original imaging reports
of MRI studies performed between June 2005 and March of 2008 on 1.5 T MR
system, in 43 patients referred with the clinical diagnosis of femoroacetabular
impingement, and who subsequently underwent hip arthroscopy. The study group
included 15 female and 28 male patients of a mean age of 37 years old, with 23
right and 20 left hips. In order to evaluate labral and chondral lesions, a comparison
was made between the imaging findings in the original report and the corresponding arthroscopy protocols.
Results: The MR imaging for labral lesions shows a sensibility of 81%, a specificity
of 92%, a PPV of 93%, a NPV of 79%, and accuracy of 90%. The MR imaging for
chondral lesions grade II and higher shows a sensibility of 59%, a specificity of
94%, a PPV of 94% and a NPV of 54%, accuracy of 94%.
Conclusion: MR imaging is an adequate method for the evaluation of labral lesions
in patients with clinical diagnosis of femoroacetabular impingement. On the other
hand, MR imaging is not a reliable method for the evaluation of chondral lesions
in these group of patients.
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10:48
Cartilage degeneration in femoroacetabular impingement: Utility of
standard diagnostic versus delayed gadolinium-enhanced magnetic
resonance imaging of cartilage (dGEMRIC) for early diagnosis
B. Bittersohl1, S. Steppacher1, T. Haamberg1, Y.-j. Kim2, S. Werlen1, M. Beck1,
K. Siebenrock1, T.C. Mamisch1; 1Berne/CH, 2Boston, MA/US
(bbittersohl@partners.org)
Musculoskeletal
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Purpose: To study the T1 patterns for different types of femoroacetabular impingement (FAI) by utilizing delayed gadolinium-enhanced MRI of cartilage (dGEMRIC)
and subsequent 3D T1 mapping. We used standard radiography for comparative
analysis.
Methods and Materials: dGEMRIC was obtained from ten asymptomatic youngadult volunteers and 26 symptomatic FAI patients. MRI included the routine hip
protocol and a dual-flip angle 3D gradient echo (GRE) sequence utilizing inline
T1 measurement. Cartilage was morphologically classified from the radial images
based on the extent of degeneration as: no degeneration, degeneration extent
0.75 cm, degeneration extent 0.75 cm, or total loss and radial T1 findings were
evaluated and correlated.
Results: The T1 distribution reflected the FAI damage pattern and was in keeping
with earlier reports. All FAI cases revealed remarkably lower T1 mean values in
comparison to asymptomatic volunteers. In cam-FAI, there was a significant drop
of T1 in the anterior to superior location. In pincer-FAI, there was no drop in the
T1 values at a specific region but a circumferential decrease was noted. Further,
T1 values revealed cartilage degeneration that was not singularly restricted to the
acetabular rim as noted with morphological MRI. High inter-observer (intra-observer)
reliability was noted for T1 assessment 0.89 (0.95).
Conclusion: We conclude that there exists a pattern of zonal T1 variation that
seems to be unique for a sub-group of FAI lesions. The dual-flip angle GRE approach to perform 3D T1 mapping demonstrates a reproducible method for further
studies of dGEMRIC and T1 in the hip joint.
B-264
10:57
Sports-related alterations of the hip joint and correlation to typical findings
in femuro-acetabular impingement: MR findings in 50 elite Karate fighters
I. Kress, K. Siebenrock, S. Werlen, T.C. Mamisch; Berne/CH (kress_inge@web.de)
Purpose: The aim of the study is to examine the morphologic changes of the hip
joint in karate fighters by MRI and investigate the influence of karate training for
developmental OA.
Methods and Materials: A total of 97 hips in 50 karate fighters were examined at
3 T MRI using axial T1-weighted 3D GRE, PD-weighted TSE fat-sat coronal and
sagittal (TR 2650, TE 21, FoV 140, 384 x 384 matrix, 3 mm slice thickness) and
intermediate-weighted TSE (TR 1850, TE 15, FoV 140, 512 x 512, 4 mm slice
thickness). Clinical examination included impingement test and range of motion.
On MRI, the shape of the femoral head and acetabulum, morphology of the labrum
and cartilage integrity were graded by two observers.
Results: In 42 hips (43.3%), the internal rotation was decreased. The mean alpha
angle was increased to 64.3 degrees with a strong correlation to age at the start
of training. The labrum was normal in 16 hips (16.5%), degenerated in 48 hips
(49.5%) and torn in 33 hips (34%). The cartilage was normal in 14 hips (15%),
degenerated in 78 (78%) hips and full thickness defects were present in 6 hips
(7%). There was a strong correlation with years of training and start of training for
labrum and cartilage abnormalities.
Conclusion: A high incidence of clinical and MR alterations of the hip was observed.
A decreased femoral head neck offset, typical for femoroacetabular impingement,
could be assessed, which correlated with the start of karate training. This indicates
a developmental component for FAI and OA of the hip joint.
B-265
11:06
Obturator externus bursa: Prevalence of communication with the hip
joint and associated intra-articular findings in 110 consecutive hip MR
arthrograms
A. Kassarjian1, J.T. Bencardino2, E. Llopis3, R.B. Schwartz4; 1Majadahonda/ES,
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New York, NY/US, 3Alzira/ES, 4Brookline, MA/US (akassarjian@partners.org)
Purpose: To demonstrate the prevalence of communication between the hip joint
and the obturator externus bursa at hip MR arthrography.
Methods and Materials: Following institutional review board approval, 110 hip
MR arthrograms were retrospectively reviewed by 2 musculoskeletal radiologists.
The presence or absence of communication between the hip joint and the obturator externus bursa was recorded. Communication between the hip joint and the
obturator externus bursa was defined as gadolinium entering the obturator externus
Scientific Sessions
bursa. The status of the acetabular labrum, articular cartilage, and presence or
absence of hip plicae were recorded.
Results: 110 hip arthrograms in 108 subjects were independently reviewed by
2 musculoskeletal radiologists. Discrepancies were resolved by consensus. The
obturator externus bursa was seen to communicate with the hip joint in 7 of 110
hip MR arthrograms. Of these, 3 were men and 4 were women. The age range was
16-54 years old with a mean age of 33 years. All seven patients had labral tears.
Five of the seven had mild degenerative changes including cartilage thinning/defects
and subchondral marrow changes. In all seven patients, labral plicae, ligamentous
plicae, and femoral neck plicae were visible.
Conclusion: The obturator externus bursa can be seen to communicate with
the hip joint in 6% of hip MR arthrograms. Associated intra-articular lesions are
common.
B-266
11:15
Purpose: To study magnetic resonance (MR) perfusion and diffusion characteristics
of bone marrow in patients with transient bone marrow edema (BME), avascular necrosis (AVN), and subchondral insufficiency fractures (SIF) of the proximal femur.
Methods and Materials: 26 patients with painful hip and BME pattern of the
proximal femur on standard MR imaging were examined using line-scan diffusionweighted EPI/HASTE and dynamic gadolinium-enhanced FLASH sequences
(1.5 T). Apparent diffusion coefficients (ADCs) and enhancement ratios (ERs) were
calculated for different regions of the proximal femur. Regional distribution and
differences in ADC and ER values over time were evaluated. Individual diagnoses
were confirmed by clinical and radiological follow-up.
Results: 12 Patients presented with transient BME, 10 with AVN and 4 with SIF of
the femoral head. Patients with transient BME showed significantly (p 0.05) higher
ADC values (1.1p0.5) than patients with AVN (0.5p0.3) or SIF (0.6p0.2). In addition,
ERs and underlying perfusion patterns of the epiphysis and metaphysis showed
significant differences between patients with AVN and transient BME.
Conclusion: The preliminary results of this study indicate that MR perfusion
and diffusion imaging may be useful additional tools to differentiate patients with
transient BME and AVN as well as SIF. These complementary imaging techniques
may also add information to the understanding of the pathophysiology of diseases
associated with bone marrow edema.
B-267
11:24
Optimisation of metal artefact reduction sequences (MARS) for MR
imaging of total hip prostheses
A.P. Toms, C. Smith, P.N. Malcolm; Norwich/UK (andoni.toms@nnuh.nhs.uk)
Purpose: Metal artefact reduction sequences (MARS) reduce susceptibility artefact
from metal prostheses using high bandwidths and matrix sizes but this comes at
a cost of loss of SNR and increased acquisition time. The aim of the study is to
describe the relative contribution of matrix size and bandwidth to artefact reduction
in order to define optimal sequence parameters.
Methods and Materials: A phantom was created using the femoral component of
a Charnley THR set in solid fat. A mid-coronal T1W (TE 12 ms, TR 400 ms) image
through the prosthesis was acquired with increasing bandwidths (150, 300, 454,
592 and 781 MHz) and for each bandwidth, images were acquired with a matrix
of 128, 256, 384, 512, 640 and 768 pixels square. Signal loss from the prosthesis
and susceptibility artefact was segmented using an automated tool.
Results: In total, 80% reduction in artefact was achieved for all bandwidths at
a matrix of 384x384. The greatest reduction in artefact occurs with a matrix of
768x768 and bandwidth of 150 MHz. However, for matrices of 512x512 or larger,
the increasing bandwidth caused a paradoxical increase in artefact. Increasing
bandwidth produced a relative fall in SNR between 49% and 56% but in practice
image quality was still satisfactory.
Conclusion: When planning MARS protocols using matrices of 512x512 or greater
are counterproductive. The optimal combination of spatial resolution and artefact
reduction can be achieved with a matrix of 384x384 and the highest achievable
receiver bandwidth.
11:33
Predictive value of MRI in rectus femoris strain injuries
R. Rodrigo, J. Santisteban, R. Ortega, F. Angulo, M. Rodriguez, M. Ereño; Bilbao/ES
(rosamonica@euskalnet.net)
Purpose: To investigate the relationship between MRI findings of rectus femoris
strain injuries and their recovery interval (RI) in professional soccer players.
Methods and Materials: A prospective study was carried out on 36 strains produced by indirect mechanisms. MRI was performed using a 1.5 GE device with
a surface coil within 1-7 days of the injury. The following MRI findings have been
correlated with clinical outcome and routine statistical analysis was performed:
anatomical location (direct tendon, indirect tendon, myoconnective or combined
injuries), site (proximal or middle third), size (cross-sectional and length), presence
of perifascial fluid or absence and T1 findings (thicker muscle, focal or diffuse hypo
/hyperintensity, blurring of myotendinous unit).
Results: The mean age was 22.1 years; mean recovery period was 28.3 days.
Regarding the anatomical structure affected, 72% had perifascial fluid: 30%
myoconnective, 27.8% indirect tendon, 36.1% direct tendon and 19.4% combined
injuries with no statistically significant difference in RI. Regarding the site of injury,
proximal lesions had longer RI (30.9 vs 24.2 days). Regarding the size of injury,
cross-sectional area injury greater than 50% had longer RI (36.6days). Lesions
with fascial fluid took longer RI (30.5 vs 22.7 days). Lesions seen on T1 had longer
RI (39.6 days; P = 0.0012).
Conclusion: MRI findings are helpful to predict the prognosis of rectus femoris
injuries. The association of three of the following four findings, proximal lesion, injury
seen on T1WI, cross-section greater than 50% and presence of perifascial fluid, are
poor outcome features with longer RI of 38.29 vs 25.9 days (P = 0.006).
B-269
11:42
Diffusion tensor MRI-based dynamic study of acute injury and frozen
recovery in rat skeletal muscle
F. Wang, S. Pan, Q. Li, Y. Sun, Q. Guo; Shenyang/CN (wangfengzhe82@163.com)
Purpose: To explore the application of DTI in the model of acute injury and frozen
recovery in rat skeletal muscle.
Methods and Materials: A total of 20 Wistar rats (female, weighing 323-451 g,
average 386 g) were divided into four groups (each of 5). Acute trauma models
were made with pressured injury machine (leg muscle, 500 N, 100 mm/min).
Among them, 5 rats in the control group were not give any interference and 15
rats in the experimental group were given ice compress at 10, 20 and 30 minutes.
MRI was performed with a 3.0 T MRI scanner (Philips Intera Achieva) before and
immediately after the injury and after 24, 48 and 72 hours. The DTI parameters
were: TR/TE = 943/65 ms, b = 600 s/mm2, six diffusion probing gradient directions,
5 mm thickness. Fiber tracking tool (PRIDE version 4.1.V3) was used to calculate
the ADC and FA values.
Results: (1) ADC and FA values were 0.68 p 0.03 x 10-3 mm2/s and 0.46 p 0.05
x 10-3 and had no statistical differences in each group before the injury. (2) ADC
values were increased to 0.77 p 0.02 x 10-3 and 0.71 p 0.03 x 10-3 mm2/s, and FA
values were decreased to 0.36 p 0.02 x 10-3 and 0.39 p 0.02 x 10-3 for controls
immediately after the injury and after 24 hours. (3)ADC values were respectively
0.71 p 0.04 x 10-3 and 0.70 p 0.02 x 10-3.0.71p0.02x10-3 mm2/s, and FA values were
respectively 0.41 p 0.03 x 10-3, 0.42 p 0.02 x 10-3 and 0.42 p 0.04 x 10-3 at the 10,
20 and 30 minutes group immediately after injury. ADC values were respectively
0.69 p 0.03 x 10-3, 0.68 p 0.04 x 10-3 and 0.69 p 0.02 x 10-3 mm2/s, and FA values
were respectively 0.42 p 0.03 x 10-3, 0.42 p 0.02 x 10-3 and 0.42 p 0.02 x 10-3 in the
three experimental groups 24 hours after injury. Compared to the control group,
the range of change in the ADC and FA values were reduced in the experimental
groups. (4) The ADC and FA values had no significant difference between the
control and experimental group at 48 and 72 hours after injury.
Conclusion: DT-MRI can non-invasively reflect the muscle acute injury and recovery
process. Frozen recovery had better efficacy to limit muscle edema due to injury.
B-270
11:51
MR perfusion imaging correlated with vessel density in a rabbit model of
hind-limb muscle tissue ischemia
W. Zhang, D. Wang, M. Men; Beijing/CN (cjr.zhangwanshi@vip.163.com)
Purpose: To evaluate the acute alteration and chronic recovery in muscle perfusion after excision of femoral artery using multiphase ce-MRI and correlate them
with new vessels density.
Methods and Materials: Acute ischemia was induced in right hind-limbs of 14 NewZealand white rabbits by complete excision of femoral artery. The acute alteration
and the chronic recovery of muscle reperfusion were examined, respectively, prior to
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Can magnetic resonance perfusion and diffusion imaging help to
differentiate transient bone marrow edema, avascular necrosis and
subchondral insufficiency fractures of the femoral head? Preliminary
results
D. Müller, J.S. Bauer, F. Walter, H. Rechl, E.J. Rummeny, K. Wörtler; Munich/DE
(dmueller@roe.med.tu-muenchen.de)
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and 0.5 hr, 1 day, 3, 7, 14, 21, 28, 42, 56, 70 days after excision of femoral artery on
a 1.5 T MR. A 5 mm-thick axial section through the middle of both femurs was imaged
using a T1weighted 2D-FLASH sequence. A bolus of Gd-DTPA was administered
then 265 image acquisitions were obtained. The percent MR signal enhancement
of the ROI (2.0 cm2) in bilateral limbs muscle was plotted and the parameters were
analyzed and compared with vessel density of specimens HE-stained.
Results: After artery excision, a significant reduction in affected muscle perfusion was observed at 0.5 hr. compared to that before excision: ArriveTime
(122p11.58 s VS 14.2p0.663 s), SI changing rates (at 10 s, 0.0055p0.002%/s VS
0.7600p0.091%/s, at 30 s, 0.0172p0.003%/s VS 0.4776p0.079%/s), Peak Height
(2.676p0.598% VS 23.54p3.206%). Perfusion recovered very slowly during the first
7 days post-excision and faster perfusion recovery was observed from 14 to 28
days, following by a slower recovery till to 70 days corresponding to the increasing
of vessel density (2.0, 1.0, 3.0, 6.0, 8.0, 9.0, 11.0, 15.0, 21.0, 18.0, respectively).
Conclusion: Multiphase ce-MR imaging could assess time-dependent changes
of muscle perfusion, which correlated with angiogenesis in a rabbit model of hindlimb ischemia.
10:30 - 12:00
Room C
Abdominal Viscera (Solid Organs)
SS 601a
Liver and bile ducts: Oncology
Moderators:
B.I. Choi; Seoul/KR
S. Terraz; Geneva/CH
B-271
10:30
Radiofrequency ablation for recurrent hepatocellular carcinoma in postoperative patients: Prognostic factors analysis
Y. Lin, Y.-Y. Chiou, Y.-H. Chou, H.-K. Wang, J.-H. Chiang, C.-Y. Chang,
H.-K. Wang; Taipei/TW (yhlin11@vghtpe.gov.tw)
Purpose: The aim of this study was to determine the prognostic factors which will
affect the disease-free survival of the post-operative patients after percutaneous
ultrasound-guided radio frequency ablation for recurrent HCC.
Methods and Materials: From August 2002 to May 2008, 82 (64 men, 18 women,
mean age: 64.27 years) patients had previous lobectomy or segmentectomy of the
liver due to HCC and suffered from tumor recurrence. Total 82 patients received initial
percutaneous RFA for recurrent HCC and were evaluated the cumulative diseasefree survival of overall intrahepatic recurrence (mean follow-up period: 14.3 p 12.4
months). Nine host, tumoral and therapeutic factors were reviewed in correlation
with disease-free survival: age, gender, hepatitis marker, ablation needle, location,
size, ablation time, post-ablation temperature and pre-ablation AFP level.
Results: The cumulative disease-free survival rate of overall recurrence was 63.5%
at one year, 24.1% at two years and 14.4% at three years. Univariate analysis
showed that tumor size, hepatitis marker and pre-ablation AFP level were significant
factors related to poor survival (P 0.05). Multivariate analysis identified that factors
related to poor survival were pre-ablation AFP level and tumor location (segment
7, 8) with a hazard ratio of 3.7 and 2.7.
Conclusion: Pre-ablation AFP level and tumor location are significant factors
related to poor survival. In patients with recurrent HCC close to liver dome and elevated AFP level, multimodality treatment or other treatments should be considered.
The result would have clinical significance for appropriate management of patients
scheduled for RFA who suffered from recurrent HCC after previous surgery.
B-272
10:39
Prediction of viable tumor in HCC treated with radiofrequency: Evaluation
of a semi-quantitative index at contrast-enhanced US (CEUS)
P. Cabassa, E. Gavazzi, E. Orlando, R. Monesi, M. Morone, R. Maroldi; Brescia/IT
(paolocab@libero.it)
Purpose: To evaluate the efficacy of a semi-quantitative index in monitoring the
therapeutic response of hepatocellular carcinoma to radiofrequency ablation (RF)
with CEUS
Methods and Materials: One month after RF, 23 consecutive HCC were evaluated.
US-guided RF was performed with expandable needles. CEUS was performed
with second-generation contrast media (SonoVue, 2.4 ml) with dedicated software
(Contrast coherent imaging). One significant frame (bitmap format) of the portal
phase was chosen for each treated lesion and analysed by software (AdobePhotoshop 7.0). Two circular manually defined regions of interest (ROI) for each
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image were drawn encompassing the treated lesion and the adjacent normal liver
parenchyma. Sonography videotape intensity (VI) was measured in gray-scale
levels (0-255) through histogram analysis for each ROI. Background intensity was
set at the same level for each image. A semi-quantitative index (VItumor-VIliver/
VIliver) was calculated. Index values were compared with 1-month MDCT (standard of reference). Statistical analysis was performed to depict the cut off value
for tumor persistence.
Results: Median index value was -0.71 (95%CI : 0.07) for necrotic lesions and -0.38
(95%CI : 0.10) for viable lesions. The value of -0.6 showed the best performance to
discriminate the viable tumor from the necrosis (sensibility 100%, PPV 100%).
Conclusion: We quantified the treatment outcome of HCC 1 month after RF ablation by a simple reproducible index. From the preliminary data, the cut off of -0.6
seems to be predictive of therapeutic success.
B-273
10:48
Safety margin assessment after radiofrequency ablation using the fusion
images of the pre- and post-RFA 3D CT scans
K. Kim1, J. Lee1, E. Klotz2, S. Kim1, S. Kim1, J. Han1, B. Choi1; 1Seoul/KR,
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Forchheim/DE
Purpose: To evaluate a new technique, the fusion images of registrated pre- and
post-RFA CT scans, for safety margin assessment after radiofrequency-ablation
(RFA).
Methods and Materials: In 31 patients with hepatocellular carcinomas, who were
treated with RFA and underwent available pre-RFA and post-RFA CT scans, the
fusion images of pre- and post-RFA CTs were created using prototype software
(HepaCare: Siemens), which uses non-rigid registration with world-coordinate
algorithm. Two radiologists (reader 1 with experience in 500 RFA cases, reader 2
with experience in 50 RFA cases) independently reviewed pre-RFA and post-RFA
CT images in two separate sessions in blinded manner; first session without fusion
images, and second session with fusion images. Degree of safety margin was rated
and compared with the reference value determined by other expert in RFA with
all information. Interobserver agreement, interpretation time, and image quality of
fusion images were evaluated.
Results: In experienced reader, good correlation between reader’s safety margin
assessment and the reference values was observed in both of first and second
interpretation sessions (r=0.916 and 0.868, respectively). In less experienced
reader, better correlation was obtained in second session than that in first session
(r=0.863 and 0.692, respectively). With the fusion images, interobserver agreement
for safety margin between the two readers increased (kappa; 0.526 in first session,
0.819 in second session). Thirty patients (96.8%) showed good image quality of
fusion image. With the fusion images, interpretation time was shortened by about
1.5 minutes (p 0.01).
Conclusion: Fusion images of pre- and post-RFA CT is a feasible and useful
technique for safety margin assessment after RFA.
B-274
10:57
Immuno-stimulating effect in thermal ablation of liver metastases from
colorectal cancer
T.J. Vogl1, M.G. Mack1, T.T. Wissniowski2, J. Hänsler2, N. Naguib1;
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Frankfurt a. Main/DE, 2Erlangen/DE (t.vogl@em.uni-frankfurt.de)
Purpose: To assess whether laser-induced thermotherapy (LITT) induces a specific
cytotoxic T-cell response in liver metastases of colorectal cancer and to define the
induced immune response.
Methods and Materials: The prospective study was approved by the institutional
review board and informed consent was obtained from all patients. Eleven patients
with liver metastases of colorectal cancer were treated with MR-guided LITT. Blood
samples were taken before and after LITT. Test antigens were autologous liver and
tumor lysate obtained from each patient by biopsy. Peripheral T-cell activation was
assessed by interferon-gamma (IFNg) secretion assay and flow cytometry. T-cells
were stained for CD3+, CD4+, and CD8+ and IFNg to detect cytotoxic T-cells. The
ratio of IFNg-positive and IFNg-negative T-cells was determined as stimulation index
(SI). To assess cytolytic activity, T-cells were co-incubated with human colorectal
cancer cells (CaCo), and release of cytosolic adenylate kinase was measured by
luciferase assay.
Results: Before LITT, SI was 12.73 (p4.83) for CD3+, 4.36 (p3.32) for CD4+ and
3.64 (p1.77) for CD8+ T-cells against autologous tumor tissue. Four weeks after
LITT, SI increased to 92.09 (p12.04) for CD3+ (P 0.001), 42.82 (p16.68) for CD4+
(P 0.001) and 47.54 (p15.68) for CD8+ T-cells against autologous tumor tissue. No
increased SI was observed with normal liver tissue at all times. Before LITT, cytolytic
activity against the respective cancer cells was low with RLU = 1493 (p1954.68),
Scientific Sessions
and after LITT it increased to RLU = 7260 (p3929.76 [P 0.001]).
Conclusion: Patients with liver metastases of colorectal cancer show tumorspecific cytotoxic T-cell stimulation with significantly increased tumor-specific
cytolytic activity of CD3+, CD4+ and CD8+ T-cells after LITT, thus defining a new
field of immune therapy.
B-275
11:06
Multidetector-row computed tomography perfusion imaging in
hepatocellular carcinoma after transcatheter arterial chemoembolization
L. Yang1, X.-P. Zhou2, X.-M. Zhang1; 1Nanchong/CN, 2Chengdu/CN
(yanglinmd@163.com)
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11:15
Predicting response of colorectal hepatic metastasis: Value of
pretreatment rim attenuation
T. Nakagawa, Y. Ryu, M. Nakadate, I. Umehara; Chiba/JP (tassei8@nifty.com)
Purpose: The purpose of this study was to determine whether the pretreatment rim
attenuations of hepatic metastatic lesions from colorectal cancer were predictive
of response to chemotherapy.
Methods and Materials: This retrospective study reviewed 42 patients with hepatic
colorectal metastases who underwent CT (16 or 64 detectors) before FOLFOX4 or
FOLIFIRI regimen. CT of upper abdomen was obtained 75-80 sec after iv injection of
iodinated contrast media. An adjusted injection rate was performed for the constant
injection time of 50 sec. On CT images, ROIs corresponding to the lesions (ROIin)
and the lesions plus rim (ROIout) were drawn. Rim attenuations were calculated
by the following formula: HUrim = (Aout × HUout - Ain × HUin)/(Aout - Ain), where
A is area (mm²) and HU is attenuation. The average value of HUrim from 3 slices
of lesions was used for the evaluation.
Results: Pretreatment rim attenuations of responders (n = 13) and non-responders
(n = 29) were 104.9 p 15.7 HU and 90.0 p 9.7 HU, respectively, and showed significant difference between them (p = 0.0060; Mann-Whitney’s U test). Progressionfree survivals of patients with low rim attenuation ( 90 HU) and the others were
4.6 p 2.9 months (n = 13) and 9.1 p 5.6 months (n = 23), respectively, and also
showed significant difference (p = 0.0194).
Conclusion: High and low pretreatment rim attenuations of colorectal liver metastases were predictors for good response and short progression-free survival,
respectively. The pretreatment rim attenuations of colorectal hepatic metastases
were predictive of response.
B-277
11:24
Added value of metabolic information in the search for primary cancer and
presence of any malignancy using FDG-PET/CT
P. Fencl1, J. Machac2, G. Kacl3, J. Weichet1, O. Belohlavek1; 1Prague/CZ,
2
New York, NY/US, 3Schlieren/CH (Pavel.Fencl@homolka.cz)
Purpose: To assess the additional diagnostic value of FDG-PET/CT in comparison to contrast-enhanced CT (CECT) in the search for primary cancer and
for the presence of malignancy in patients with cancer of unknown primary (CUP)
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11:33
Diagnostic value of image fusion of MRI and FDG-PET in patients with
suspected primary liver and pancreatic malignancies
C.S. Reiner, O.F. Donati, T.F. Hany, B. Marincek, D. Weishaupt; Zurich/CH
Purpose: To investigate the value of image fusion of magnetic resonance imaging
(MRI) and positron emission tomography (PET) on the diagnostic confidence for
the assessment of lesion dignity and presence of regional lymph node metastases
in patients with suspected primary liver or pancreatic malignancies.
Methods and Materials: 26 patients (13 women, 13 men; mean age 54.9 years)
with suspected primary liver or pancreatic malignancies who underwent contrastenhanced MRI and (18)F-fluordeoxyglucose-PET were included. Manual, rigid
image registration with six degrees of freedom and fusion of MRI and PET-data
sets was performed. Two independent readers separately assessed MR images
alone and in combination with fused PET/MRI images. Images were analyzed using
a five-point-confidence scale for dignity of lesions and the presence of regional
lymph node metastases. Results were correlated to histopathology. The data were
analyzed using receiver operating characteristic (ROC) curves.
Results: 15 patients had a primary liver malignancy, 8 patients had pancreatic
cancer, and 3 patients benign lesions. In determining lesion dignity, the mean areas
under the ROC curves were 0.95 for MRI and 1.0 for PET/MRI for reader 1 (p 0.05),
and 0.88 for MRI and 1.0 for PET/MRI for reader 2 (p 0.05). The Az-values for
detection of regional lymph node metastases were low, except for the subgroup of
liver malignancies (MRI: 0.79/0.66, PET/MRI: 0.80/0.98 for reader 1/2).
Conclusion: Fused PET/MRI images may increase the confidence for dignity
assessment in patients with suspected primary liver and pancreatic malignancies. The technique may also be beneficial for detection of possible lymph node
metastases.
B-279
11:42
Classification of response to treatment in liver metastatic disease:
Comparison between volume and unidimensional measurements on MRI
M. Mantatzis, S. Kakolyris, K. Amarantidis, G. Daskalogiannakis, I. Mokali,
A. Karagiannakis, P. Prassopoulos; Alexandroupolis/GR (mmantatz@med.duth.gr)
Purpose: The response to treatment of liver metastases on imaging is currently
based on lesions’ diameter measurements, proposed by RECIST (Response Evaluation Criteria in Solid Tumors). The aim of the study was to compare RECIST criteria
with volumetric measurements in the evaluation of response to treatment of patients,
with liver metastases, undergoing chemotherapy.
Methods and Materials: A total of 44 patients with colorectal cancer and newly
diagnosed liver metastases were included in this prospective study. Patients
underwent three MRI examinations, at treatment initiation, during chemotherapy
and immediately post-treatment. Measurements based on RECIST guidelines and
volume calculations were performed on the “target” lesions (TL) and patients were
stratified in four response categories.
Results: The two methods were in agreement in 64/77 of patients and 253/301 of
individual lesions classification in response categories (“good” agreement, Cohen
Kappa = 0.735 and 0.741, respectively). In 16.88% of the comparisons the two
methods stratified patients to different response categories. Of the TLs, 27.6%
did not follow the response category of the patient where lesions were located
(“moderate” agreement, Cohen kappa = 0.542), reflecting the presence of various
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Purpose: To study the value of multidetector-row computed tomography (MDCT)
perfusion imaging in hepatocellular carcinoma (HCC) after transcatheter arterial
chemoembolization (TACE).
Methods and Materials: Twenty-four consecutive patients with HCC who received
TACE were prospectively evaluated with MDCT perfusion imaging within one week
before and one month after TACE. The CT perfusion parameters such as hepatic
arterial perfusion (HAP), hepatic portal perfusion (HPP), total liver perfusion (TLP)
and hepatic arterial perfusion index (HAPI) were calculated using the slope method,
respectively. The correlation between the values of CT perfusion parameters in
tumors before TACE and the levels of iodized oil deposition in HCC after TACE
was performed by using spearman correlation analysis, and the difference of the
CT perfusion parameter values in HCC before and after TACE was performed with
t-statistic. The P value cutoff for statistical significance was set at 0.05.
Results: The values of HAP and TLP in tumors before TACE showed significant
positive correlation with the levels of iodized oil deposition in tumors after TACE
(P 0.05, respectively), the values of HPP and HAPI were not related to the levels
of iodized oil deposition (P 0.05, respectively), and the average values of HAP, TLP
and HAPI in tumors decreased significantly one month after TACE compared with
those before TACE (P 0.05, respectively), the value of HPP grossly unchanged
after TACE compared with that before TACE (P 0.05).
Conclusion: MDCT perfusion imaging is a useful modality for evaluating prognosis
of patients with HCC after TACE.
syndrome.
Methods and Materials: CECT data of FDG-PET/CT in 72 patients were investigated by Biograph Duo. LSO due to CUP were randomly split into three subgroups
of 36 patients each and blindly reevaluated by three experienced radiologists.
Sensitivity (SE), specificity (SP) and accuracy (ACC) was defined for FDG-PET/CT
as well as for each CECT reader, based on gold standard (histology and/or clinical follow-up). McNemar´s and Fisher’s tests were used for comparisons between
groups; inter-reader agreement was expressed by kappa.
Results: For diagnosing primary, SE was 63% for FDG-PET/CT and 44, 45 and
38% for CECT readers; SP was 80% for FDG-PET/CT and 72, 35 and 79% for
CECT readers; ACC was 76% for FDG-PET/CT and 66, 38 and 70% for CECT
readers. There were significant differences between FDG-PET/CT and one CECT
reader in SP and ACC. In diagnosing the presence of neoplasm, SE was 93% for
FDG-PET/CT and 86, 92 and 88% for CECT readers; SP was 84% for FDG-PET/
CT and 43, 38 and 81% for CECT readers; ACC was 86% for FDG-PET/CT and
59, 57 and 84% for CECT readers. There were significant differences between
FDG-PET/CT and two CECT readers in SP and ACC. Inter-reader agreement in
ACC was weak (kappa 0.00-0.37).
Conclusion: In this group of patients, FDG-PET/CT was more specific and accurate
than CECT. CECT was significantly reader-dependent.
Scientific Sessions
malignant cell clones. The actual volume of TLs differs from the calculated volume
of a sphere with the same diameter by 98%. Wilcoxon z = -5.03, P b 0.001 suggesting that the "sphere model" may be inappropriate.
Conclusion: Differences between RECIST criteria and volumetric measurements
question the accuracy of assessment by linear measurements. Volumetric techniques may overcome certain disadvantages of the currently used unidimensional
measurements.
to flow measurements. This promising new method needs clinical validation.
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Purpose: The purpose of the paper is to describe the imaging features of intraductal
papillary neoplasms of the bile ducts based on the pathologic findings.
Methods and Materials: Imaging findings of 53 cases with intraductal papillary
neoplasm of the bile ducts were retrospectively reviewed by two radiologists and the
results were correlated with pathologic findings. Based on the pathologic features,
one pathologist classified the shape of the intraductal neoplasms as mass forming,
cast-like growing, cyst forming (with or without intracystic mass) and superficially
spreading. On imaging, the shape of the mass was categorized as mass forming
when there was apparent mass in the bile duct with or without hepatic parenchymal
invasion; cast-like growing type when the mass filled the dilated bile duct in a relatively long segment; cyst forming type when the involved ducts showed cystically
dilated bile duct, which resembled aneurysm with or without intracystic nodules or
masses; superficial spreading type when lobar or segmental bile ducts were dilated
markedly without apparent mass.
Results: Of the 53 cases of intraductal papillary neoplasms, there were 16 cases
of mass-forming, 17 cases of cast-like growing, seven cases of cyst forming, nine
cases of superficially spreading and four cases of the combined type.
Conclusion: Intraductal papillary neoplasm of the bile ducts can be classified into
intraductal mass forming, cast-like growing, aneurysmal dilatation of the bile ducts
with or without intracystic mass or disproportionately severe dilatation of the lobar
or segmental intrahepatic bile ducts without apparent masses.
Purpose: To analyze prospectively the efficacy of interventions in acute dysfunctional hemodialysis fistulas, respecting interventionalist, time of day, and lesion
type.
Methods and Materials: Institutional Review Board approval was obtained. From
2005 to 2007, all the (n = 280) patients with acute dysfunctional hemodialysis fistula
were immediately referred to intervention suite, irrespective of time of day. In n =
241 cases, intervention was performed. Following procedural success rates were
calculated: total, by interventionalist (experienced, A-C; less experienced, D-I),
by time of day (routine staff, 07:00a.m.-04:00p.m.;emergency staff, 04:00p.m.07:00a.m)., and by lesion type (stenosis; sclerotic occlusion; thrombotic occlusion;
mixed stenosis/occlusion). Two-sided level of significance was set at p 0.025 for
interventionalist and lesion type, and one-sided level of significance was set at
p 0.05 for time of day.
Results: Total success rate was 62%(149/241). Success rates by interventionalists
were 76%(32/42) for A (p = 0.068), 72%(26/36) for B (p = 0.083), 64%(21/33) for C
(p = 0.600), 54%(15/28) for D (p = 0.787), 52%(12/23) for E (p = 0.770), 64%(9/14)
for F (p = 0.449), 50%(6/12) for G (p = 0.722), and 70%(7/10) each for H and I (p
= 0.193), respectively. Success rates by time of day were 68%(93/136) for routine
staff, and 53%(56/105) for emergency staff (p = 0.047). Success rates by lesion
type were 82%(94/104) for stenosis (p 0.01), 39%(13/33) for sclerotic occlusion
(p = 0.083), 18%(6/33) for thrombotic occlusion (p 0.01), and 59%(36/61) for
mixed stenosis/occlusion (p = 0.484), respectively.
Conclusion: 1) Success rates by interventionalist did not reach level of significance.
2) With routine staff available, interventions in acute dysfunctional hemodialysis
fistulas are more likely to be successful. 3) Stenosis is very likely to be treated
successfully, while thrombotic occlusion is not.
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B-284
11:51
Morphologic classification of intraductal papillary neoplasm of the bile
ducts: Radiologic-pathologic correlation
J. Lim, H. Lim, D. Choi, K.-T. Jang, J. Lee; Seoul/KR (jh0329.lim@samsung.com)
Room E1
SS 609a
Venous and renal interventions
Moderators:
I. Battyány; Pécs/HU
T. Lupattelli; Milan/IT
10:39
Detection of hemodialysis vascular access stenosis by intravascular pulse
pressure analysis: An in-vitro study
R.N. Planken1, K. van Canneyt2, S. Eloot2, P. Verdonck2; 1Amsterdam/NL, 2Gent/BE
(nilsplanken@gmail.com)
Purpose: Vascular access (VA) thrombosis, due to significant stenoses ( 50%),
is the main cause of VA failure in hemodialysis patients. Flow measurements enable detection of stenoses 70% and not 50%. Flow measurements regularly
fail to prevent thrombosis. The purpose of the study was to test a new technique
for detection of significant stenoses ( 50%).
Methods and Materials: A pulsatile in-vitro model of a radio-cephalic arteriovenous
fistula with silicone tubes, a reservoir and a pump was created. A 15G needle was
introduced at 5 and 10 cm downstream of the anastomosis. Intravascular pulse
pressure amplitude (systolic minus diastolic pressure = PP) was measured in the
arterial inflow and at the arterial needle. PP ratios were calculated (PP-needle/
PP-inflow*100%). A 50% stenosis was introduced in the arterial inflow, between
needles and in the venous outflow, successively. Measurements were repeated
at different heart rates (60-90 beats/min) and different flows (500-1,300 ml/min).
ANOVA analysis and post-hoc tests were used to evaluate the relation between
the PP ratio and the presence of a stenosis in different conditions.
Results: PP ratios were 20.26 p 4.55% (no stenosis), 7.69 p 2.08% (arterial inflow
stenosis), 36.20 p 2.12% (between needles stenosis) and 32.38 p 2.17% (venous
outflow stenosis). Stenoses can be located upstream and downstream of the needle
(P 0.001). Between needles stenoses and venous outflow stenoses could also
be distinguished (P 0.001).
Conclusion: Pulse pressure analysis enables detection of 50% stenosis independent of heart rate and flow volume. It also enables stenoses localization, in contrast
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10:48
Interventions in acute dysfunctional hemodialysis fistulas: Prospective
analysis of efficacy in 241 cases
P.J. Schaefer, N. Charalambous, F.K.W. Schaefer, M. Heller, T. Jahnke; Kiel/DE
(jp.schaefer@rad.uni-kiel.de)
10:57
Retrieval of a new optional vena cava filter
S. Pieri1, P. Agresti1, L. Pancione2, D. Laganà3, G. Carrafiello1; 1Rome/IT, 2Torino/IT,
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Varese/IT (stepieri@excite.it)
Interventional Radiology
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Purpose: The role of vena cava filter has changed over the last decades. Optional
vena cava filters, removable after a long permanence, is the novelty that overcomes
the limits of temporary and permanent filters. We report our observations and
problems connected with the retrieval of a new filter.
Methods and Materials: Between 1999 and 2005, 276 filters were implanted.
Retrieval was attempted in 78, with transjugular approach and directly observation under fluoroscopy of the capture of the head of the filter by the legs of the
retrieval system.
Results: Technical success was 93%. In the 6 cases of failure, the main reason was
the angle of the filter with the vena cava. Difficulties were found in the 72 procedures
completed: in 10 patients (12.8%) there was a difficulty in covering the gripper filter
with the retrieval sheat after the initial capture (non alignment of the filter). 6 cases
required the use of other devices in order to facilitate better positioning in axis with
the retrieval system. Median stay was 173 days.
Conclusion: The optional vena cava filter with long permanence is a useful
surgical aid. Despite problems connected with a physiological learning curve,
in our experience their retrieval proved feasible in the majority of cases, without
complications.
B-285
11:06
Incidence, outcome and prognostic factors of post TIPS liver dysfunction
in patients with cirrhosis
A. Luca1, A. D’Antoni1, R. Miraglia1, G. Vizzini1, B. Gridelli1, J. Bosch2;
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Palermo/IT, 2Barcelona/ES (aluca@ismett.edu)
Purpose: To evaluate the short-term (within 6 weeks) effects of elective TIPS on
liver function in patients with cirrhosis, define incidence and outcome of post TIPS
liver dysfunction (PTLD) and identify prognostic factors of PTLD.
Methods and Materials: We analyzed data from 192 consecutive cirrhotic patients
who underwent elective TIPS. PTLD was defined as presence of at least two of
following criteria: bilirubin 3 mg/dl (if 3 mg/dl prior TIPS) or increase 100%
(if 3 mg/dl prior TIPS), decrease of prothrombin time 30 points%, decrease of
albumin 10 g/dl, encephalopathy II stage.
Scientific Sessions
Results: TIPS was placed for refractory ascites and/or hydrothorax (52%) and
recurrent variceal bleeding (48%). Twenty-six (13.5%) patients developed PTLD.
Three patients died within 6 weeks, 3 patients died within 6 months, 5 patients
underwent liver transplantation from 1.5 to 6 months after TIPS (all them were on
waiting list for LT before TIPS), and in 15 patients PTLD reverted over the follow-up.
Patients who developed PTLD had a lower survival at 6-weeks (87 vs. 100%,
p 0.05) and 6-months (72 vs. 96%, p 0.05) compared with patients without PTLD.
Multivariate analysis revealed that higher serum bilirubin (p=0.0001) and younger
age (p 0.004) were independently associated with the risk of PTLD.
Conclusion: PTLD is not uncommon in patients with cirrhosis who underwent
elective TIPS, and although in more than 50% of cases it is transitory in the other
cases is cause of death or requires liver transplantation. Serum bilirubin and younger
age are independent prognostic factors of PTLD.
B-286
11:15
Purpose: To define the role, efficacy and feasibility of TIPS in non-cirrhotic patients
with symptomatic portal cavernoma refractory to standard therapy.
Methods and Materials: From March 1998 to November 2007, 24 non-cirrhotic
symptomatic patients with portal cavernomatosis (symptoms: ascites, intestinal
ischeamia, variceal bleeding, and varices at high risk of bleeding) were admitted
to our hospital. Fifteen patients (62.5%) responded satisfactorily to medical and/or
endoscopic therapy. Nine patients (37.5%) did not responded completely to standard therapy and were evaluated for a TIPS. One patient was excluded because
of bilateral occlusion of the internal jugular vein. TIPS was performed in 8 pts
(33.3%) only with a trans-jugular access using a thin needle (21G) TIPS-set for
the direct search of the portal axis. Portal vein was crossed in 7 patients (87.5%)
and a Viatorr stent (WL Gore) was successfully implanted. Early shunt thrombosis
was observed after 2 days in one patient with complete occlusion the splenic and
superior mesenteric vein and in which the stent was positioned in a large collateral
vein arising from the portal vein.
Results: After a mean follow-up of 17 p 10.5 months a primary patency rate was
71% (5/7 patients) with a secondary patency rate of 83.3% (6/7). One patient died
of hepatocarcinoma with patent shunt 6 months after the procedure.
Conclusion: TIPS can be considered safe and effective in non-cirrhotic patients
with symptomatic portal cavernoma refractory to standard therapy or in need of
anticoagulation.
B-287
11:24
Percutaneous portal vein embolisation for extended hepatic resection:
Volume gain and achievement of operability in 85 patients
A. Koops1, E. Ramcic1, G. Krupski2, G. Adam1; 1Hamburg/DE, 2Reinbek/DE
Purpose: Percutaneous portal vein embolisation is an established procedure for
the induction of segmental liver hypertrophy in primarily irresectable liver malignancies. The purpose of this study was to assess the increase of the left-lateral
segmental volume and the achievement of operability in patients with intended
extended right hepatectomy.
Methods and Materials: Portal vein embolisation was performed in 85 patients
with primarily irresectable liver malignancies. A mixture of histoacyl/lipiodol was
placed in the complete course of all accessible portal branches of segments 4-8 by
subxiphoidal left-sided (71%) or lateral right-sided (29%) approach. CT was used
for volumetry before and every of 3-4 weeks after embolisation until the patients
reached the necessary future remnant liver size (prospected remnant weight of
at least 0.8% body weight). The clinical definition of operability was determined
by this volume gain, but also by tumor development, secondary CT findings, and
the general state of health.
Results: After a mean interval of 32 days a left-lateral segmental volume gain of
138 ml (59%) was found, with a hypertrophy rate of 4.3 ml/d (2.1%/d). In 52 of 85
patients (61%), complete tumor resection by extended right hepatectomy was successfully performed. Continuous inoperability in 33 patients was caused by tumor
progression, new manifestation in the future liver remnant, or new extrahepatic
metastases in 56% of these cases; only 9% were due to insufficient volume gain.
Conclusion: Portal vein embolisation is a promising preoperative interventional
procedure for the induction of segmental liver hypertrophy to achieve operability
in initially inoperative patients.
11:33
Role of superselective renal tumors transcatheter embolization before
laparoscopic partial nephrectomy: Methods, safety and efficacy
G. Vallati, G. Pizzi, L. Carpanese, R. Kajal, M. Crecco; Rome/IT (vallati@ifo.it)
Purpose: Perioperative bleeding, during laparoscopic nephron-sparing surgery
(NSS), is a quite common event. The authors evaluated the effectiveness of selective trans-arterial renal tumors embolization (TAE) before laparoscopic NSS for
reducing periprocedural haemorrhagic complications.
Methods and Materials: From August 2003 to January 2008, TAE was performed
in 80 patients with small, hypervascular, predominantly exophitic, renal tumor. Median tumor size was 3.5 cm; no lesion was found adjacent to the collecting system.
TAE was performed through the vessels feeding the tumor and the surrounding
parenchyma, in order to obtain a small controlled necrotic area. A total of 78 patients
underwent selective TAE with polyvinylalcohol 300-500 µm sized particles while in
only two, acrylic glue was used. Angiographic absence of further arterial feeders
confirmed the procedure efficacy. About 6 hours after TAE, patients underwent a
laparoscopic NSS. Mean operative time was measured, as well as mean estimated
blood loss and post-operative outcome.
Results: No loss of significant viable renal tissue occurred after TAE. Mean operative time of laparoscopic NSS was of 45 minutes and a mean estimated blood loss
was of 50 ml. No patient required blood transfusion. Average hospital length stay
was 5 days; complications were only reported in three patients.
Conclusion: Laparoscopic NSS is recognized as a valid alternative to open surgery. However, the rate limiting step of this technique is to achieve an adequate
hemostasis. Pre-operative TAE of kidney tumors seems to be a safe technique that
should be used before laparoscopic NSS for effective management of possible
perioperative active renal bleeding.
B-289
11:42
Percutaneous temporary vessel occlusion for robotic partial nephrectomy
with a thermoplastic polymer
S. Flacke1, J. Merhige2, A. Moinzadeh1, K.G. Lyall3, J. Wilkie2, C.W. Bakal1,
J. Libertino1, J.-M. Vogel2, P. Madras1; 1Burlington, MA/US, 2Woburn, MA/US,
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Sunnyvale, CA/US (Sebastian.Flacke@lahey.org)
Purpose: To demonstrate the feasibility of reversible vessel embolization using a thermoplastic polymer to provide complete hemostasis for partial robotic
nephrectomy.
Methods and Materials: After isolation of the left kidney of 7 anaesthetized pigs
(50-70 kg) using a daVinci-S-HD system (Intuitive Surgical), a renal angiogram
was performed using a 7 F guiding catheter (Veripath, Guidant) placed in the left
main renal artery. 5 F C2-catheter (Cook) was inserted into upper or lower pole
segmental artery, respectively, followed by embolization using a thermoplastic polymer (LeGoo-XL™, Pluromed). After complete hemostasis of the targeted region, a
partial robotic nephrectomy was performed and the kidney subsequently sutured.
Residual occlusion was reversed by injecting cold saline through the catheter and
reperfusion was documented. Degree and duration of hemostasis was determined.
Concentration and preparation of the polymer was modified in five animals. Reproducibility of the technique was confirmed in the remaining experiments.
Results: A 20% polymer concentration in a 43% contrast solution (Omnipaque
300) injected at room temperature with a fast manual injection of 0.2 ml followed
by a slow injection of up to 0.5 ml under fluoroscopic control occluded a segmental
renal artery for more than 45 minutes. The visual appearance of the plug was used
to determine the total amount of polymer needed. Hemostasis achieved during
surgery was superior to standard clamping techniques. Cold saline dissolved
residual polymer.
Conclusion: A thermoplastic polymer can be used for reversible occlusion of
segmental renal arteries for minimal invasive surgery eliminating warm ischemia
of the unaffected kidney and clamping of the renal vessels.
B-290
11:51
Ablation of symptomatic cysts using n-butyl cyanoacrylate and iodized oil
in autosomal dominant polycyst kidney disease: Long-term results
S. Kim1, S. Kim2, J. Cho2, B. Cho2; 1Daegu/KR, 2Seoul/KR (kseehdr@hanmail.net)
Purpose: To assess the long-term results of cyst ablation with N-butyl cyanoacrylate
(NBCA) and iodized oil in autosomal dominant polycystic kidney disease (ADPKD)
patients with symptomatic cysts.
Methods and Materials: Cyst ablation using mixture of NBCA and iodized oil was
performed in 99 cysts of 21 patients with symptoms, such as abdominal distension and pain. The collapse or reaccumulation of ablated cysts after the procedure
was assessed during 36 to 90 months follow-up. The treatment effects, including
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The role of TIPS in non-cirrhotic patients with symptomatic portal
cavernoma
E. Boatta, F. Fanelli, F. Salvatori, M. Corona, M. Allegritti, P. Rossi, R. Passariello;
Rome/IT
B-288
Scientific Sessions
symptom relief and clinical data such as blood pressure and serum creatinine levels
were also assessed together with complication.
Results: The 77 of 99 cysts (80%) were totally or partially collapsed. The eight
cysts were not collapsed after the procedure. The 14 of ablated cysts were reaccumulated during long-term follow-up. The 17 of 21 patients (76%) were obtained
in symptom relief. The four of 12 patients (33%) with hypertension, and the two
of six patients (33%) with azotemia were improved. The six of 21 patients (28%)
were developed in ESRD at averaging 72 months duration. Significant complication
was not encountered.
Conclusion: This procedure may be an effective and safe method to ablate the
symptomatic cysts in ADPKD.
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Breast
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Moderators:
M. Bazzocchi; Udine/IT
M.A.A.J. van den Bosch; Utrecht/NL
10:30
Multicenter clinical experience with the new direct frontal 360 degree
vacuum assisted large core biopsy device (Coramate®) (n=175)
R. Schulz-Wendtland1, M. Verjans2, J. Gelin3, L. Rotenberg4, M. Sentis5,
G. Verswijfel6, J. Janssens7; 1Erlangen/DE, 2Tienen/BE, 3Goeteborg/SE,
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Neuilly-sur-Seine/FR, 5Barcelona/ES, 6Gent/BE, 7Diepenbeek/BE
(janssens.ecp@skynet.be)
Purpose: Recent innovations in large core biopsies for the human breast led to the
development of unique direct frontal and 360 degree vacuum aspiration systems
(Coramate®). Preclinical and single center clinical trials proved the usefulness of
this method. Now the multicenter clinical experience is described.
Methods and Materials: Between 10/06 and 3/07, 175 women with a suspect
lesion (BI-RADS™ 4/5) were eligible for biopsy. Anticoagulant medication was allowed. No prior sedation was given. The lesion was detected by clinical examination,
mammography, ultrasound, and/or MRI (BI-RADS™ 4/5). The performance of the
sampling method, the comfort of the patient, and sample quality was examined.
The accuracy of diagnosis is evaluated by comparing the pathology results of the
samples and definitive pathology at subsequent surgery.
Results: N=175 patients/lesions (BI-RADS™ 4/5): N=42 patients/lesions (BIRADS™ 4); N=133 patients/lesions (BI-RADS™ 5). N=133 patients/lesions (BIRADS™ 5), following L-CNB (Coramate®): 132 (invasive ductal cancer) (98%),
1 false-negative (DCIS) (2%). An average of 1.73 biopsies per procedure was
obtained. The average diameter 4.07 mm with a length of 1.28 cm. All patients
had sufficient sample size to make a diagnosis. None of the patients suffered from
a serious complication and the procedure was in general extremely well tolerated.
Postprocedure esthetic results were excellent.
Conclusion: The direct frontal approach with 360° vacuum aspiration is a new
technology (Coramate®) that gives excellent diagnostic results without major patient
discomfort and with high quality tissue samples. The system is particularly useful
in various difficult situations at low costs.
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10:39
Percutaneous core needle biopsy of benign papillary lesions of the breast:
Incidence and variables associated with atypia and carcinoma at surgical
excision
V. Londero, A. Linda, C. Zuiani, E. Vianello, A. Furlan, M. Bazzocchi; Udine/IT
(londero.viviana@aoud.sanita.fvg.it)
Purpose: To retrospectively evaluate the outcome of the cases of benign papillary
lesions diagnosed with breast core-needle biopsy.
Methods and Materials: Surgical or imaging follow-up (r2 years) was available
in 132 women (age range, 33-83 years; mean age: 56 years) with 140 benign
papillary lesions diagnosed on sonographically guided core-needle biopsy (128)
or stereotactically guided vacuum-assisted biopsy (12). Patient age, clinical presentation, mammographic and sonographic appearance, size, BI-RADS category,
biopsy guidance (sonographic or stereotactic) and device (14G core-needle biopsy
or 11G vacuum-assisted biopsy) and percutaneous diagnosis (sclerosing papilloma
or intraductal/intracystic papilloma or papillomatosis) were retrospectively analysed.
The results were compared with the histologic findings at surgery (113) or follow-up
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Sonographically guided core needle biopsy of nonpalpable architectural
distortions BI-RADS category 4 A-B: Correlation with surgical excisional
biopsy and follow-up
M. Baeva, J. Oliver Goldaracena, S. Alonso Roca, M. Arguelles Pintos,
J. Blanco Cabellos, M. Dominguez Franjo, R. Garcia Perez; Madrid/ES
(mbaeva@fhalcorcon.es)
Intervention
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imaging with no change at the 2-year follow-up (27). Statistical analysis was performed using the Fisher's exact test (statistically significant: P-value 0.05).
Results: Of 140 benign papillary lesions at core-needle biopsy, upgrade to malignancy was found in 14 (10%) cases and to atypia in 8 (6%) cases. Of the mammographically detected carcinomas and atypical lesions, 55% (6/11) presented as a
non-calcified mass, 45% (5/11) as a calcified mass and 0% (0/11) as calcifications
(P = 0.022). Patient age, clinical presentation, sonographic appearance, size, BIRADS category, biopsy guidance and device, and percutaneous diagnosis were
not significant factors in determining the presence of malignancy or atypia.
Conclusion: Clinical, sonographic and biopsy features could not be used reliably
to predict the presence of carcinoma or atypia, while mammographic appearance
might be helpful. Because of the high prevalence of carcinoma and atypia in these
lesions, percutaneous diagnosis of benign papillary lesions is an indication for
surgical excision.
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Purpose: To show the advantage of sonographically (US) guided core needle
biopsy of nonpalpable architectural distortions (NPAD), BI-RADS category 4 A-B,
visible on mammography for histological diagnosis and for patient management
and decision making.
Methods and Materials: A retrospective review of 1,550 lesions sampled with a
14G core needle biopsy performed in our hospital from January 2001 to March
2007 yielded 92 NPAD BI-RADS category 4 A-B. Of all, 67 (on 66 patients, age
range 27-92, median 62) were also visible on US, and US-guided core needle
biopsy was performed. The lesions size on US ranged from 3 to 17 mm, median
6 mm. The number of obtained specimens ranged from 5 to 11, median 8. A total
of 58 patients underwent excisional surgical biopsy and 8 patients were followed
mamographically for a mean of 67 months (range 18-72 months).
Results: The core needle biopsy results were 49 malignant or high-risk lesions
and 18 benign lesions. All of the malignant and high-risk lesions were confirmed
as such after surgical excisional biopsy and underwent excision. Correlation with
gold standard showed sensitivity 0.93, specificity 1, positive predictive value 1 and
negative predictive value 0.86. Mammographic follow-up in the 10 cases that did
not undergo excision was performed for 6-96 months, with none showing mammographic or sonographic changes.
Conclusion: The US-guided core needle biopsy allows accurate histological
diagnosis of NPAD BI-RADS category 4 A-B visible on mammography; therefore,
it is a useful guide in making management decisions and allowing a conservative
approach for benign lesions.
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10:57
MR-guided vacuum-assisted biopsies: Results in 93 patients
C. Malhaire, C. El Khoury, A. Tardivon, F. Thibault, A. Athanasiou, P. Petrow,
L. Ollivier, S. Neuenschwander; Paris/FR (caroline.malhaire@curie.net)
Purpose: To present our results of MR-guided vacuum-assisted biopsies.
Methods and Materials: A total of 97 patients ([58-79 years], mean: 51 years) with
97 isolated MR lesions (negative second-look ultrasound examinations) classified
as BI-RADS category 4 or 5 were addressed for vacuum-assisted biopsies. In this
population, 29 patients were at high risk (BRCA1 = 16, BRCA2 = 7, familial risk =
6) and 29 had a suspicion of local recurrence of breast cancer. Four procedures
were cancelled (undetected lesion = 2, technical problems = 2). Using a 10-gauge
vacuum-assisted biopsy probe (Vacora, Bard) on a 1.5 T scanner (Siemens), 93
lesions (focus = 2, mass lesion = 39, non-mass lesion = 52) were sampled, followed
by clip placement. In case of benign results, MRI follow-up (28 patients, 30-1,057
days, median 220 days) or mammography (15 patients, 140-1,680 days, median
369 days) was performed.
Results: A mean of 20 specimens was obtained per lesion (mean time procedure
75 min, [50-131 min]). At pathology, 47 lesions were benign, 13 at high risk (papillary = 2, radial scar = 1, atypical epithelial hyperplasia = 10) and 33 malignant
(ductal carcinoma in situ = 8, invasive cancers = 25). Three false-negative results
(3%) were identified and three complications (3%) occurred (one malaise, one
skin defect, one infection).
Conclusion: MR-guided vacuum-assisted biopsies represent a safe alternative to
surgical biopsy for lesions identified at MR imaging only.
Scientific Sessions
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11:06
MR-guided vacuum-assisted core-needle breast biopsy: Comparison of
three vacuum-assisted biopsy devices
J.M. Scarth, W. Teh; Harrow/UK (juliascarth@doctors.org.uk)
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11:15
Breast MRI for ductal carcinoma in situ: Should we perform it before
vacuum-assisted biopsy?
M. Lorenzon, N. Martini, C. Zuiani, V. Londero, M. Bazzocchi; Udine/IT
(michele.lorenzon@gmail.com)
Purpose: Assessing sensitivity of breast MRI performed before and after 11 Gauge
Vacuum-Assisted Biopsy (VAB) for the detection of Ductal Carcinoma In Situ (DCIS)
in patients with microcalcifications at Mammography.
Methods and Materials: We retrospectively reviewed 90 cases with suspicious
microcalcifications at Mammography who underwent a 1.5 T MRI before or after
VAB, all of them with a final diagnosis of pure DCIS on excision. Cases demonstrating contrast enhancement with morphologic and kinetic features suspicious for
malignancy in the corresponding site of microcalcifications were considered as true
positive. Our population was divided into 2 groups: Group 1 (G1) was composed
of 44 patients who underwent MRI before VAB, Group 2 (G2) was composed of 46
patients who underwent MRI after VAB. The overall sensitivity of MRI for DCIS was
assessed. A comparison between MR sensitivity in the two groups was performed
and a C2 test was applied to assess a statistically significant difference.
Results: Overall sensitivity of MRI for DCIS was 78.8%. MRI sensitivity in G1 was
90.1%, in G2 67.4%. The difference in sensitivity between G1 and G2 was statistically significant (23.7%, p = 0.0133).
Conclusion: Due to the scant appearance of certain DCIS, performing breast
MRI after VAB could lead to a false negative result. In our practice, MRI performed
before VAB exhibits a higher sensitivity for DCIS than after VAB.
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11:24
Radial scars at percutaneous breast biopsy: Variables associated with
underestimation of malignancy and atypia
A. Linda, C. Zuiani, V. Londero, N. Martini, R. Girometti, M. Bazzocchi; Udine/IT
(annalinda33@gmail.com)
Purpose: To define the rate and variables associated with underestimation of
malignancy and atypia when a radial scar (RS) is diagnosed on percutaneous
breast biopsy.
Methods and Materials: The records of 4,458 patients who underwent imagingguided breast biopsy during an 8-year period were retrospectively reviewed. Surgical
or imaging follow-up (r24 months) was available in 75 women with 76 RS diagnosed at stereotactically guided vacuum-assisted biopsy (VAB) or sonographically
guided core-needle biopsy (CNB). Biopsy (mammographically guided VAB versus
sonographically guided CNB), mammographic and sonographic (detectability, BIRADS category, mammographic and/or sonographic appearance and size) features
were reviewed by two readers and correlated with surgical and imaging follow-up
that served as the reference standard. The Fischer's exact test was used for the
difference in biopsy and imaging features. A P-value 0.05 was considered to be
statistically significant.
B-298
11:33
Direct MR-galactography in patients with pathological nipple discharge:
Add on or substitute for conventional galactography?
E. Wenkel, S.A. Schwab, R. Janka, K. Melzer, M. Uder, R. Schulz-Wendtland,
W.A. Bautz; Erlangen/DE (evelyn.wenkel@uk-erlangen.de)
Purpose: To evaluate the clinical value of direct magnetic resonance galactography (dMRG) in combination with magnetic resonance mammography (MRM)
compared to conventional galactography (KGal) in patients with pathological
nipple discharge.
Methods and Materials: A total of 25 patients (age range 30-85 years) underwent
KGal, dMRG and the standard MRM protocol. The dMRG consisted of a sagittal
T1-weighted 3D FLASH (fast low angle shot) sequence (TR 21.0 ms; TE 4.8 ms;
matrix 512 x 512; resolution 0.4 x 0.4 x 2 mm, acquisition time: 4 min 42 sec).
KGal and dMRG were blinded and analyzed independently in random order by
two radiologists. All patients underwent surgery.
Results: One patient was excluded from the evaluation because ductal filling was
not possible. Histology revealed benign findings in 19/24 women and malignant
findings in 5/24 women. There was no difference in the evaluation of the KGal
and the dMRG between examiner 1 and 2 regarding duct position and depth of
the pathological finding. On comparing KGal and dMRG, in seven patients, both
examiners had different results. In six patients, it was caused by a different ductal
filling status in KGal and dMRG. In one woman, a different duct was filled in dMRG
compared to KGal. In seven patients, surgical procedures were modified due to
the results of dMRG and MRM.
Conclusion: DMRG, in combination with MRM, allows preoperative localization
of the pathological duct and estimation of the extent of the pathology responsible
for the nipple discharge.
B-299
11:42
Radioactive seed localization of nonpalpable breast lesions
L.S.F. Yo, A.W. Daniels-Gooszen, L.E.M. Duijm, Y.E.A. van Riet, G.A.P. Nieuwenhuijzen,
M. van Beek, F.H. Jansen; Eindhoven/NL (RONLDM@cze.nl)
Purpose: To determine the feasibility of localization of nonpalpable breast lesions by 125-iodine labelled radioactive seeds as an alternative to traditional wire
localization.
Methods and Materials: We consecutively included 289 women with a malignant,
nonpalpable breast lesion at percutaneous core biopsy. Localization was performed
with a 4.5 by 0.8 mm titanium seed, labelled with 125-iodine and an activity of 7KBq.
At lumpectomy, the surgical oncologist used a Neoprobe 2000 gamma detector,
both for the peroperative seed tracing and sentinel node procedure.
Results: Respectively, 243 (84.1%), 42 (14.5%) and 4 (1.4%) localizations were
performed using ultrasound guidance, stereotactic guidance or a combination of
both modalities. For adequate localization, more than one seed was necessary in 43
(14.9%) procedures (multifocal disease: 18; extensive microcalcifications: 9; technical difficulties: 16). Mean localization time was 14 minutes (range, 10-35 minutes)
and seeds were located within 1 centimeter from the edge of a lesion in 282 procedures (97.6%). Mean time between localization and surgery was 28 days (range
1-231 days) for the whole study population and 174 days (range, 78-231 days)
for those patients (31 women) who underwent neoadjuvant chemotherapy prior to
lumpectomy. A total of 50 patients (16.0%) showed irradical tumour resection at
lumpectomy, necessitating re-excision or amputation in 29 patients (9.3%).
Conclusion: Nonpalpable breast lesions can be localized accurately by 125-iodine
labelled radioactive seeds. This technique may have great potential, especially for
women undergoing neoadjuvant chemotherapy. In these patients, lumpectomy
can be performed even several months after localization by 125-iodine labelled
radioactive seeds.
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Purpose: To review our experience with the Bard Vacora handheld, the Mammotome-MR “open vacuum” and the Suros ATEC “closed vacuum” assisted biopsy
systems.
Methods and Materials: Retrospective analysis of all MRI vacuum breast biopsies
performed between March 2006 and August 2008.
Results: A total of 117 biopsies were performed on 108 women, 15 using Vacora,
54 with Mammotome-MR and 48 with the ATEC devices. The average biopsy time
with Vacora was 46 minutes (32-83) with an average of 8 cores (1-2), and lesion
size of 18 mm (5-90 mm). A total of 47% were malignant with one discordant result
subsequently diagnosed as malignant. The average time on the Mammotome-MR
was 50 minutes for 1 biopsy and 62 minutes for 2 biopsies (range 35-94), with an
average number of 17 cores (4-32) and lesion size of 13.8 mm (3-70). A total of
30% of biopsies had a malignant result with two benign results subsequently diagnosed as malignant. However, more posterior and anterior lesions (n = 14, 26%)
were accessed with the Mammotome-M system using ‘pillar band post’ guidance.
The average biopsy time with ATEC was 39 minutes for 1 biopsy and 53 minutes
for 2 biopsies (range 24-62), with an average of 23 cores (8-46) and lesion size of
14.2 mm (4-100). 29% were malignant with no discordant cases.
Conclusion: Procedure times were longer with fewer cores using the Mammotome
and Vacora; however, Mammotome-MR allowed biopsy of lesions that would not
be accessible with the other devices.
Results: Surgical excision was performed on 62 (81%) lesions of which 50 (81%)
were benign, 7 (11%) atypical and 5 (8%) cancers. The remaining 14 (19%) lesions
were unchanged at the 2-year follow-up. Overall percutaneous biopsy underestimation rate of malignancy was 6% (5/76), with 8% (4/52) for sonographically guided
CNB and 4% (1/24) for stereotactically guided VAB (P = 0.937). On the comparison
of mammographic and sonographic features between benign and malignant or
atypical lesions, none of the evaluated findings showed a significant difference
between the two groups.
Conclusion: Percutaneous breast biopsy is associated with significant sampling
error in case of diagnosis of RS. No imaging findings are able to predict which
patients require subsequent surgery. For this reason, all patients with RS at CNB
or VAB should undergo surgical excision.
Scientific Sessions
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11:51
B-302
10:39
Do radiologists receive a significant radiation dose localising breast
lesions ultrasonically following radio-isotope sentinel lymph node
imaging?
R.T. Meades, W.E. Svensson, K.S. Nijran, J.W. Frank, V. Gada, G. Ralleigh,
N. Barrett; London/UK
Right ventricular (RV) delayed enhancement (DE) in patients with
idiopathic pulmonary arterial hypertension (IPAH): Final results and
prognostic value on cardiac MR (CMR)
F. Calabrese, M. Francone, I. Iacucci, M. Mangia, C. Catalano, R. Passariello;
Rome/IT (francescaantonella@interfree.it)
Purpose: Impalpable breast cancers are usually treated with breast preserving
excision, guided by wire localisation, and radio-isotope guided axillary sentinel
node biopsy. When wire placement follows radio-isotope sentinel node imaging,
there is a radiation exposure to the radiologist placing the wire under ultrasound
guidance. This risk has not previously been assessed.
Methods and Materials: The radiation doses, received by radiologists placing
wires under ultrasound control following nuclear medicine sentinel node imaging,
were measured for procedures on the day of surgery (20 MBq of isotope) and the
day before surgery (40 MBq of isotope). These measurements were compared with
calculated theoretical values of dose for each procedure.
Results: A total of 12 cases studied showed comparable results between actual
dosages and estimated dosages; mean measured dose 1.8 µSv (estimated 1.8
µSv) for same day surgery cases and 4.8 µSv (estimated 3.4 µSv) for next day
surgery cases.
Conclusion: For a worst case scenario this study shows that a radiologist, doing
12 wire localisations immediately following radio-isotope sentinel node imaging on
the day before surgery, would receive a radiation dose (0.06 mSv) equivalent to that
of one chest X-ray which is equivalent to an additional life time risk of fatal cancer
of one in a million. This raises several questions. Are radiologists performing presurgical localisation informed when they are doing it after sentinel node imaging?
Are they aware of the relative risk? Is this risk acceptable? Should wire localisation
always be performed before radio isotope injection of patients undergoing sentinel
lymph node biopsy?
Purpose: IPAH is a progressive disease characterized by raised pulmonary vascular resistance, without identifiable cause, which results in diminished right heart
function due to increased right ventricular afterload. CMR has emerged as primary
non-invasive diagnostic tool for comprehensive assessment of RV function, quantification of myocardial mass and detection of fibrosis. The purpose of this study is
to discuss final results and prognostic value of DE in patients with IPAH.
Methods and Materials: A total of 57 patients (age range 18-67 years) with clinical diagnosis of IPAH were referred to our Department for CMR evaluation from a
reference national center. In all cases right heart hemodynamic parameters were
available. An MRI study that included short-axis and horizontal long-axis cine-SSFP
imaging and DE acquisitions after contrast-administration (0.1 mmol/kg bodyweight
Gd-BOPTA) was acquired in all cases. After data acquisition,ventricular mass
index, ejection fraction, end-diastolic, end-systolic and stroke volume index were
determined. Presence, location and extent of DE were also analyzed and fibrosis
was correlated with RV mass and pulmonary arterial pressure (PAP).
Results: Myocardial DE was demonstrated in 43/57 (75%) patients and predominantly confined to the RV insertion points (27/43; 63%) and interventricular septum
(16/43; 37%); in 2 cases concomitant LV involvement was found and 7 cases exam
was interrupted. Extent of fibrosis correlated positively with RV mass (r = 0.59, p
= 0.038) and PAP (r = 0.64, p < 0.01)and inversely with RV ejection fraction (r =
-0.69, p < 0.05).
Conclusion: DE was observed in most patients. The extent of DE is significantly
related to right ventricular systolic disfunction and insertion points are particularly
prone to developing fibrosis, which can be used as a prognostic value in patients
with IPAH.
10:30 - 12:00
Room I
Cardiac
B-303
SS 603a
Right heart and pulmonary arteries
Moderators:
A. Küttner; Erlangen/DE
K. Pagonidis; Iraklion/GR
B-301
10:30
Non-invasive measurement of elevated mean pulmonary arterial pressure
G. Reiter, U. Reiter, G. Kovacs, B. Kainz, K. Schmidt, R. Maier, H. Olschewski,
R. Rienmüller; Graz/AT (gert.reiter@siemens.com)
Purpose: Manifest pulmonary hypertension is a disease characterized by an elevation in mean pulmonary arterial pressure (mPAP), which is measured invasively
via right heart catheterization. Based on magnetic resonance velocity imaging and
three-dimensional flow visualization, the periods of existence of a vortex of blood
flow in the main pulmonary artery were investigated to examine if they can be used
as non-invasive measure of elevated mPAP.
Methods and Materials: A total of 46 patients with manifest pulmonary hypertension underwent right heart catheterization and time-resolved, three-dimensional
magnetic resonance phase contrast imaging of the main pulmonary artery (with a
mean delay of 5 days). Velocity fields resulting from phase contrast measurements
were calculated and visualized with dedicated software. Relative periods of existence of a vortex of blood flow in the pulmonary artery (with respect to the cardiac
interval) were determined visually and independently by two observers.
Results: Observer agreement was high (intraclass correlation coefficient of 0.97).
In all 46 patients, a vortex of blood flow in the main pulmonary artery was detected.
The Pearson correlation coefficient between the relative period of existence of a
vortex and mPAP was 0.94 with 95% confidence interval from 0.89 to 0.97. The
standard deviation from the linear regression line was 4 mmHg.
Conclusion: Vortices of blood flow in the main pulmonary artery allow an accurate
measurement of elevated mean pulmonary arterial pressures. It is anticipated
that this method may be a powerful tool for prognostic assessment of manifest
pulmonary hypertension.
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10:48
Long-term follow-up of patients after corrected tetralogy of fallot:
An MRI study
M. Grothoff, L. Lehmkuhl, J. Hoffmann, M. Gutberlet; Leipzig/DE (grothoff@gmx.de)
Purpose: Evaluation of volumetric and functional parameters in long-term follow-up
examinations after corrected tetralogy of Fallot (TOF) by cardiac MRI.
Methods and Materials: 44 pts., 28 male, were studied using a 1.5 T Gyroscan
ACS-NT (Philips). Mean age surgical repair was 3.2 years (range 1 month to
51.5 years). Mean age at initial MRI-study was 15.7 years. Further MR-data was
acquired each regular outpatient visit (range 0.5 to 11y). Volumetric measurement
was performed with a cine gradient echo sequence with breathhold technique. To
quantify pulmonary regurgitation-fraction, we performed a velocity encoded flow
measurement in the main pulmonary artery in a transverse section. Acquired data
was analyzed with a Mann-Whitney-U Test.
Results: There was a non significant decrease of right ventricular ejection fraction (p 0.05; mean at first exam. 53%; mean at last exam. 45%). RV end-diastolic
volume index increased from 109 to 167 ml/m² (p 0.05). Pulmonary regurgitation
fraction changed from 28 to 35% (p 0.05). No change could be seen in RV end
diastolic wall mass.
Conclusion: Cardiac MRI is an excellent method for follow-up examinations in patients after corrected tetralogy of Fallot. Even slight changes in function and volumes
can be detected. In long term follow-up late after repair, we found little impairment
of ventricular function and a significant increase of right ventricular volume.
B-304
10:57
Magnetic resonance-derived three-dimensional blood flow patterns as
marker of manifest pulmonary hypertension
U. Reiter, G. Reiter, G. Kovacs, B. Kainz, K. Schmidt, R. Maier, H. Olschewski,
R. Rienmüller; Graz/AT (ursula.reiter@klinikum-graz.at)
Purpose: Manifest pulmonary hypertension is a disease, which is diagnosed
invasively via right heart catheterization. Based on magnetic resonance velocity
imaging and three-dimensional flow visualization, the existence of a vortex of
blood flow in the main pulmonary artery was investigated to examine if it can be
used as non-invasive diagnostic criterion for the detection of manifest pulmonary
hypertension.
Methods and Materials: A total of 93 patients with suspected pulmonary hypertension underwent right heart catheterization and time-resolved, three-dimensional
Scientific Sessions
magnetic resonance phase contrast imaging of the main pulmonary artery (with
a mean delay of 5 days). Catheter-measured mean pulmonary artery pressure
exceeding 25 mmHg was used for the diagnosis of manifest pulmonary hypertension. Velocity fields resulting from phase contrast measurements were calculated
and visualized with dedicated software. Two observers performed visual analysis
of the velocity fields with respect to the existence of vortices of blood flow in the
pulmonary artery independently and blinded to the catheter results.
Results: Kappa index for the detection of vortices was 1.00. Whereas in all 44
patients with manifest pulmonary hypertension a vortex was found, no vortex
was detected in 46 of the 49 patients without manifest pulmonary hypertension.
This resulted in a sensitivity of 1.00 and a specificity of 0.94 with 95% confidence
intervals from 0.92 to 1.00 and from 0.83 to 0.99.
Conclusion: The existence of a vortex of blood flow in the main pulmonary artery allows the accurate identification of manifest pulmonary hypertension. Their
measurement can be performed within a routine cardiac magnetic resonance
investigation.
B-305
11:06
Purpose: To assess the diastolic function in patients with constrictive pericarditis
using velocity-encoded flow measurements
Methods and Materials: A total of 22 patients with constrictive pericarditis were
referred to MRI before pericardectomy, while 20 healthy subjects served as controls. Maximum pericardial thickness, end systolic and end diastolic ventricular
volumes and septal motion during diastole were assessed. Velocity-encoded flow
measurements were performed at the level of the atrioventricular valves. Maximum
velocity of E- and A-waves was measured and the E-/A-wave ratios calculated. The
correlation coefficient of E-/A-wave ratios at the tricuspid valve and right ventricular
end diastolic pressure (RVEDP) were calculated in patients with CP.
Results: Abnormal pericardial thickening was found in 17 of 22 patients with CP
and in none of the healthy subjects. The mean right and left ventricular end diastolic
volumes were significantly smaller in patients with CP (rvEDV [ml]: 120 p 21 vs.
155 p 20, P 0.001; lvEDV [ml]: 119 p2 7 vs. 152 p 26, P 0.001). Pathologic septal
motion was detected in all but one patient with CP and all healthy volunteers had a
normal septal configuration during diastole. Measurements at the tricuspid valves
showed a significantly lower E-/A-wave ratio in patients with CP in comparison
to healthy subjects (1.2 p 0.4 vs. 1.7 p 0.4; P 0.001). The correlation coefficient
between the right ventricular E-/A-wave ratios and right ventricular end diastolic
pressure measurements in patients with CP was r = 0.589 (P = 0.01).
Conclusion: In addition to morphological signs, velocity-encoded flow measurements are a valuable tool in the assessment of diastolic dysfunction in patients with
CP and allow detection of increased end diastolic right ventricular pressure.
B-306
11:15
Dual energy CT for the assessment of pulmonary perfusion
T.R.C. Johnson1, S. Thieme1, C. Lee2, J. McWilliams2, H. Leuchte1, C.R. Becker1,
M.F. Reiser1, K. Nikolaou1; 1Munich/DE, 2Los Angeles, CA/US
(Thorsten.Johnson@med.uni-muenchen.de)
Purpose: The purpose of this study was to assess the feasibility and potential
diagnostic value of dual energy (DE) CT iodine mapping in pulmonary CT angiography (CTA).
Methods and Materials: CTA was acquired in DE technique in 93 patients on a
dual source CT scanner. Postprocessing was applied to map iodine in the lung
parenchyma based on its spectral behavior and the image quality was assessed.
Lung perfusion was rated as homogeneous, patchy or with circumscribed defects.
Normal CTA images reconstructed from the same data sets were reviewed for
the presence and localization of pulmonary embolism (PE), indicating partial or
complete embolic occlusion and changes in the lung parenchyma. DE perfusion
findings were correlated with those of CTA and lung window in a per-patient and
a per-segment analysis.
Results: Iodine distribution was homogeneous in 49 patients, of whom CTA showed
no PE in 46 and non-occlusive PE in 3 patients. A total of 29 patients had a patchy
pattern, of whom 24 had no PE and 5 non-occlusive PE, with solely non-occlusive
intravascular clots. A total of 15 patients had segmental or sub-segmental defects,
4 without evidence of PE and 11 with occlusive PE and at least one occlusive clot
in the pulmonary vasculature.
Conclusion: DECT is reliable in detecting pulmonary defects in pulmonary perfusion corresponding to embolic vessel occlusion.
11:24
Alternative approach in a single breath-hold for right ventricle functional
and volumetric quantification
G. Ligabue, F. Fiocchi, M. Modena, P. Torricelli; Modena/IT
(guido.ligabue@unimore.it)
Purpose: As the evaluation of the right ventricle is reported to be challenging
due to its complex anatomy, the aim of the study was to compare the agreement
among functional and volumetric parameters of both ventricles depicted by two
different MRI sequences.
Methods and Materials: Sixty-nine patients (mean age: 53.6 y/o; 32% female)
were included. Exclusion criteria were echocardiographic evidence of intra/extra
cardiac shunt and valvular disease. The conventional b-FTE sequence on short
axis view (10-12 slices; 8 mm thickness; gap = 0.8 mm; SENSE = 1.6; scan time
= 102 p 17 sec) was compared to a single breath-hold on horizontal long axis (10
slices over continuous; 8 mm thickness; SENSE = 4; scan time = 26 p 2 sec). In
both acquisitions the following functional and volumetric parameters were evaluated for right and left ventricle: stroke volume (SV), end-diastolic volume (EDV),
end systolic volume (ESV). Left ventricle indexes on short axis were considered
as the reference gold standard.
Results: An excellent correlation between the parameters was obtained by
both different approaches. SV were as follows: on short axis view left ventricle
81.5 p 18.6 ml (gold standard) and right ventricle 73.1 p 18.9 ml; on horizontal
long axis left ventricle 80.7 p 18.9 ml and right ventricle 78.5 p 17.5 ml. The best
agreement for right ventricle was obtained by comparing SV on the long axis in a
single breath-hold (Pearson r = 0.893; p 0.001) to the gold standard respect to
right ventricle evaluation on short axis (Pearson r = 0.89; p 0.001).
Conclusion: The evaluation of the right ventricle in a single breath-hold on horizontal long axis allows a high rate of reliability.
B-308
11:33
Cardiac magnetic resonance in the assessment of right ventricular
involvement in patients with acute and chronic myocardial infarction:
Prevalence and prognostic implications
M. Mangia, M. Francone, I. Iacucci, F. Vasselli, C. Catalano, R. Passariello;
Rome/IT (mangia.matteo@gmail.com)
Purpose: Right ventricular involvement occurs in about one-half patients with
inferior AMI and it defines a significant clinical entity associated with considerable immediate morbidity and mortality and a well-delineated set of priorities for
its management. Diagnosis is based on clinical findings, early recording of the
electrocardiogram and elevated right-sided filling pressures; echocardiographic
assessment of the right ventricle (RV) also remains technically difficult. The present
study sought to assess the feasibility of late enhancement (LE) cardiac magnetic
resonance (CMR) to detect RV infarctions and to evaluate its prevalence.
Methods and Materials: A total of 97 patients with acute (n = 58) or chronic myocardial infarction (MI; n = 31) were retrospectively assessed. All patients underwent
CMR using a 1.5 T scanner (Siemens Avanto, Germany); imaging protocol included
SSFP cine-MR sequences, TSE T2w STIR, 1st pass perfusion and LE imaging
acquired after Gd-BOPTA administration (Bracco Multihance, Milan, Italy). Images
were analyzed assessing the presence of LE enhancement for each segment and
data were matched with both ECG and trans-thoracic echo.
Results: Of 97 pts 31 had inferior MI, 62 had anterior MI and 4 had extensive MI.
RV LE was observed in 22/97 cases (22%): 13/31 (41%) inferior MI; 9/62 (14%)
anterior MIs. In the subgroup of inferior MI, ECG + echocardiography showed RV
involvement in 12/22 cases (54%); no hints of RV involvement were observed in
the anterior MI pts. RV infarctions showed larger RV ED volumes as compared to
others (163 p 27 mL vs 132 p 11 mL P = 0.37).
Conclusion: LE CMR is more sensitive than ECG and echocardiography in
detecting RV infarction.
B-309
11:42
Multidetector row cardiac computed tomography accurately quantifies
right ventricular size and function using multiphase contrast-saline
mixture injection with dual flow: Comparison with cardiac MRI
Y.G. Gao, K. Li, X. Du, Y. Shen; Beijing/CN (wsggy518@yahoo.com.cn)
Purpose: To explore the value of multiphase contrast-saline mixture injection with
dual-flow in measurement of right ventricular (RV) function using ECG-gated multidetector row CT (MDCT) compared with cardiac magnetic resonance (CMR).
Methods and Materials: Twenty-six subjects prospectively underwent ECG-gated
CT and CMR examinations on a 64 MDCT and 1.5 T MR scanners, respectively.
Contrast bolus was followed by a contrast saline mixture at 70:30 ratio on CT
examination. Contiguous multiphase short-axis images were generated from axial
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Correlation of right ventricular end diastolic pressure and E/A ratios
in the assessment of diastolic function with MR velocity-encoded flow
measurements in patients with constrictive pericarditis
K.U. Bauner, M. Schmoeckel, M.F. Reiser, A.M. Huber; Munich/DE
(Kerstin.Bauner@med.uni-muenchen.de)
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Scientific Sessions
CT data, and steady-state free precession cine MR produced contiguous short-axis
cines. Semiautomated software generated ventricular borders to calculate volume,
mass, and ejection fraction (EF) from both sets of images. Two experienced radiologists completed quantification of RV function and wall motion analyses of 26 CMR
and CT data sets independently.
Results: There was a good visualization of the wall of the right ventricle and
interventricular septum and a good visualization of uniformity of the right ventricle
using multiphase contrast-saline mixture injection with dual-flow. All measures of
RV size and function by MDCT correlated well with CMR over a wide range of
RV function (RVEF 38-60% by CMR), including end-diastolic volume (r = 0.97),
end-systolic volume (r = 0.97), EF (r = 0.97), and mass (r = 0.95). For segments
adequately visualized by both techniques, the mean kappa statistic was 0.88,
consistent with good agreement.
Conclusion: Using multiphase contrast-saline mixture injection with dual-flow,
MDCT accurately quantifies RV size and function. RV quantification with cardiac
CT requires optimized contrast opacification of the RV.
B-310
B-312
11:51
Survived sudden cardiac death of non-coronary origin: Contrast-enhanced
cardiac MRI in the differential diagnosis of the underlying pathology
P. Hunold1, T. Schlosser2, K. Nassenstein2, O. Bruder2, H. Eggebrecht2,
P.W. Radke1, J. Barkhausen1; 1Lübeck/DE, 2Essen/DE (peter.hunold@uk-sh.de)
Purpose: Sudden cardiac death (SCD) is most commonly caused by acute myocardial infarction. However, in cases with normal coronary arteries, SCD often remains
unexplained. The aim of this study was to evaluate the use of contrast-enhanced
cardiac MRI in defining the underlying pathology of survived SCD without coronary
artery occlusion.
Methods and Materials: More than 6,000 contrast-enhanced cardiac MRI studies
from 3 different hospitals were reviewed for cases of survived SCD with angiographically proven normal coronary arteries. The MRI protocol (1.5 T) consisted of
a functional left ventricular study using a segmented SSFP sequence. Data sets for
late gadolinium enhancement detection were acquired 8-15 min after 0.2 mmol/kg
BW of Gd using a segmented inversion-recovery TurboFLASH / FGRE sequence (TI,
200-260 ms; slice thickness, 8 mm). All cases of non-coronary SCD were reviewed
and the different underlying pathologies as defined by MRI were collected.
Results: In total, 18 cases were identified. In 14 patients thereof, MRI could state
the diagnosis based on typical imaging features: Primary cardiomyopathy was
found in 7 patients (arrhythmogenic right ventricular cardiomyopathy, 2; dilated
cardiomyopathy, 3; hypertrophic cardiomyopathy, 1; isolated left ventricular noncompaction, 1). Acute myocarditis and acute sarcoidosis were found in 3 patients
each. Chronic aneurysm of the anterior wall of unknown origin was found in 1
patient. In 4 patients, no pathology was found.
Conclusion: Contrast-enhanced MRI is an utmost valuable tool for the diagnostic
work-up of survivors of unclear SCD. This underlines the role of MRI as the first
line technique in myocardial disease.
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Room L/M
Neuro
SS 611
Tumors
Moderators:
D.P. Auer; Nottingham/UK
T.F. Gotwald; Innsbruck/AT
B-311
10:30
Impaired peritumoral BOLD signal using cerebral fMRI
Z. Jiang, E. Ramos Bombin, E. Barbier, I. Tropres, D. Hoffmann, S. Grand,
F. Berger, J.-F. Le Bas, A. Krainik; Grenoble/FR (j102@163.com)
Purpose: To identify pathophysiological mechanisms associated with impaired
peritumoral BOLD signal using fMRI.
Methods and Materials: A total of 21 patients referred for resection of primary frontal or parietal neoplasms, respecting primary sensorimotor cortex (SM1) (low grade
glioma (LGG) (n = 6); high grade glioma (HGG) (n = 6); menigioma (n = 9)), were
examined preoperatively using BOLD fMRI during motor tasks. Whole-brain BOLD
signal was estimated using carbogen inhalation. Analyses were conducted using
SPM5. Using bolus of gadolinium, cerebral blood flow (CBF) and volume (CBV), and
mean transit time (MTT) were estimated. Using a 1 cm3 region-of-interest centered
on maximal T-value in SM1 contralateral to movements, interhemispheric asymmetry
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was evaluated using ratios (rSM1 = ipsitumoral SM1/contratumoral SM1) for motor
BOLD (rSM1mot), carbogen BOLD (rSM1carbo), and perfusion parameters (rSM1CBF;
rSM1CBF; rSM1MTT). Statistical analyses were conducted using SPSSv14.
Results: During hand movements contralateral to the tumor, ipsitumoral sensorimotor activations were decreased in HGG and meningioma. Regression analysis
showed that distance between tumoral border and SM1 accounted for variance
of rSM1mot (B = 0.47). Tumoral volume, CBV, CBF, and MTT were not selected to
model rSM1mot. However in meningioma, MTT was increased in ipsitumoral SM1.
rSM1mot was correlated to rSM1carbo (R = 0.51). Moreover, 94.5 p 5.2% of motor
BOLD activations were included in carbogen BOLD maps.
Conclusion: Impaired sensorimotor activations in the peritumoral cortex were detected in HGG and meningioma. In HGG, abnormal neurovascular coupling related
to disruption of the brain-blood-barrier is likely, and need further investigations. In
meningioma, increased MTT suggests loco-regional hypoperfusion related to a steal
phenomenon. Carbogen BOLD maps might be used as spatial mask for fMRI.
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10:39
Role of intra-tumoral diffusion tensor matrices in grading gliomas
S.N. Patro, M.B. Jolapara, C. Kesavadas, A.K. Gupta, J. Saini, N.K. Bodhey;
Trivandrum/IN (drsatyanpatro@gmail.com)
Purpose: Diffusion weighted (DWI) with tensor imaging (DTI) gives information
about the amount and directionality of water diffusion occurring in a given tissue.
Here, we study the role of diffusion tensor matrices including mean diffusivity (Dav),
exponential diffusion (Dexp), fractional anisotropy (FA) and spherical anisotropy
(CS) in grading the gliomas. We hypothesize that high-grade tumors, which have
increased cellularity, show increased Dexp and FA and decreased Dav and CS.
Methods and Materials: We performed DTI in a total of 31 patients, of which 14 had
high grade gliomas (HGG, WHO grade III & IV), 15 had low grade (LGG, WHO grade
II) and two had diffuse infiltrating gliomas (WHO grade II). We measured Dav, Dexp,
FA and CS values in areas of tumor and in normal appearing white matter (centrum
semiovale and splenium of corpus callosum). Each patient had undergone either
surgery or biopsy. Histopathological diagnosis was established in all cases.
Results: The mean Dexp and FA values were higher in HGG (412p123 and 382p92)
than LGG (224p47 and 139p36), while mean Dav and CS values were lower in
HGG (921p 442 and 650p90) than LGG (1519p198 and 875p31). The difference
in the diffusion tensor indices between HGG and LGG was found to be statistically
significant with p-value of 0.0001. Diffusion tensor matrices in diffuse infiltrating
gliomas were similar to HGG.
Conclusion: In addition to conventional MR sequences, the values of diffusion tensor
matrices such as Dav, Dexp, FA and CS can help differentiate HGG from LGG.
B-313
10:48
Magnetic resonance spectroscopy and perfusion longitudinal follow-up of
low-grade gliomas
C. Hlaihel1, L. Guilloton1, J. Honnorat2, J. Guyotat2, F. Cotton1; 1Lyon/FR, 2Bron/FR
(chadi.hlaihel@gmail.com)
Purpose: To evaluate the role of proton magnetic resonance spectroscopy associated with MR perfusion in the follow-up of low-grade gliomas, since conventional
MR imaging is not sufficient to detect anaplastic transformation.
Methods and Materials: A total of 22 patients with histologically proved low-grade
glioma were followed up using proton spectroscopy, MR perfusion and conventional
MR studies. Follow-up MRIs had been performed on the third month of evolution
and then twice a year with a mean of five MR studies per patient.
Results: Five patients had an anaplastic transformation. Choline to creatine ratio
with a threshold at 2.4 was more efficient than perfusion MR (rCBV) in detecting
the transformation, with a sensitivity of 100% and a specificity of 88%. Increased
choline seems to appear at an average 15 months before the elevation of rCBV.
The mean annual growth was 3.34 mm. A growth rate higher than 3 mm per year
was correlated with a greater risk of anaplastic transformation.
Conclusion: rChol/Cr elevation may allow an early detection of the anaplastic shift,
nearly a year before an elevation of rCBV. Proton magnetic resonance spectroscopy
should be recommended in the follow-up of low-grade gliomas since the choline
values seem to be modified earlier than MR perfusion.
Scientific Sessions
B-314
10:57
Astrocytic tumors: Correlation of susceptibility-weighted imaging at 3 T
with histopathologic grade
M. Hori1, N. Shiraga1, S. Aoki1, H. Mori1, K. Ohtomo1, M. Shimada1, A. Yamaguchi1,
T. Araki2; 1Tokyo/JP, 2Yamanashi/JP (masahori@med.toho-u.ac.jp)
B-315
11:06
In comparison of high b-value diffusion-weighted imaging with standard
b-value in cerebral gliomas at 3 T MR
M. Cihangiroglu1, O. Kilickesmez1, Z. Firat1, N. Comunoglu1, D. Kara1, A. Demir1,
U. Ture1, I. Kovanlikaya2; 1Istanbul/TR, 2New York, NY/US (mmutlucihan@hotmail.com)
Purpose: To investigate the usefulness of the standard (b=1000 s/mm²) and high
b value (b=3000 s/mm²) DWI in discriminating the high and low grade cerebral
gliomas at 3 T MRI.
Methods and Materials: 59 patients (38M, 21 F, mean age 43) enrolled in this
study. 25 patients had WHO grade IV, 12 patients grade III and 22 patients grade
II gliomas. All MR imaging were performed at 3 T MRI (Philips). In quantitative assessment, apparent diffusion coefficient (ADC), signal intensity (SI) ratio (tumor SI/
normal SI), signal to noise ratio (SNR), contrast to noise ratio (CNR), contrast ratio
(CR) values were compared between at b=1000 and b=3000 DWI.
Results: The difference between SI ratio, SNR and ADC values of grade II and IV
gliomas were found statistically significant at b1000 and b3000. SI ratio and SNR
values of cerebral gliomas at b3000 are significantly lower than b1000 (p .05).
ADC values of grade II and III gliomas at b1000 and SI ratio values of grade II and
III gliomas at b3000 were significantly different. ADC values of high grade gliomas
at b1000 and b3000 were lower than low grade gliomas (p .05). CR values of grade
II and IV were found statistically significant at b3000. In terms of CNR, there was no
significant difference between low and high grade gliomas at b1000 and b3000.
Conclusion: In addition to differences of SI, SNR and ADC values at both b
values, CR value at high b value DWI might contribute in discriminating high and
low grade gliomas.
B-316
11:15
Using a 64-slice CT perfusion imaging permeability surface to evaluate the
histopathologic grade of intracranial gliomas
Z. Jiawen1, F. Xiaoyuan1, L. Bin2, Y. Yongqiang2; 1Shanghai/CN, 2Hefei/CN
(zhangjw2000@hotmail.com)
Purpose: To detect the value of the permeability surface (PS) using a 64-slice CT
perfusion imaging in preoperative grading gliomas.
Methods and Materials: A total of 31 glioma patients (11 low-grade and 20 highgrade gliomas) underwent 64-slice CT cerebral perfusion examination before
operation. Low-grade and high-grade groups were categorized corresponding to
WHO grade I or II gliomas and WHO grade III or IV gliomas, respectively, as determined by histopathological examination. The absolute value of PS was obtained
from regions of maximal abnormality in tumor parenchyma on PS color perfusion
maps. Data were processed using SPSS 11.5 software. The receiver operating
characteristic (ROC) curve was used to assess their values in distinguishing the
low-grade and high-grade gliomas.
B-317
11:24
Differentiating radiation necrosis from recurrent gliomas: Depiction
with contrast-enhanced susceptibility-weighted MR imaging correlated
with 11C-methionine positron-emission tomography and histopathologic
findings
T. Nishiguchi, M. Hosono, T. Tada, N. Tsuyuguchi, Y. Inoue; Osaka/JP
(tomokazu-n@med.osaka-cu.ac.jp)
Purpose: Determining whether progressively enhancing lesions in patients treated
previously are radiation necrosis (RN) or recurrent gliomas remain a challenge. The
purpose of this study was to evaluate if intralesional susceptibility effect (SusE)
seen with post contrast-enhanced susceptibility weighted imaging (CE-SWI) can
provide reliable information for differentiating RN and recurrent gliomas.
Methods and Materials: Fourteen progressively enhancing lesions were examined
longitudinally on the basis of the following criteria: gliomas treated previously by
radiation therapy following histopathological diagnosis, subsequent new progressive enhancement, and inconclusive diagnosis on follow-up MRI. Six lesions were
diagnosed as RN according to the result of clinical course and lesion uptake/normal
frontal cortex ratio on 11C-methionine positron-emission tomography or histopathology. Eight lesions were histopathologically proved as recurrent gliomas. CE-SWI
(TR/TE/flip angle: 48/40/20, resolution 0.7*0.9*1.6 mm) was obtained at 1.5 T for
all cases. Qualitative evaluation of the degree and frequency for SusE on CE-SWI
was performed compared to the intensity of the vein of Galen.
Results: High degree of SusE (H-SusE) was seen in 5/6 (83%) of RN, by contrast noted in 1/8 (12%) of recurrent gliomas. Intermediate to low degree of SusE
(Int-SusE) was seen in 4/6 (66%) of RN whereas seen in 6/8 (75%) of recurrent
gliomas. Histopathological findings suggested that H-SusE, significantly observed
in RN, reflected hemosiderin deposition and calcification, whereas Int-SusE to
conglomerate of proliferated vessels.
Conclusion: A meticulous analysis of the nature of SusE would provide additional
insight into tissue characteristics, and might aid in differentiating RN from recurrent gliomas.
B-318
11:33
Cerebral blood volume measurements by perfusion-weighted MR imaging
in gliomas: Ready for the prime-time in predicting short-term outcome and
recurrent disease?
S. Bisdas1, P. Giglio2, I. Burck3, C. Welsh2, I. Xyda4, M. Spampinato2,
Z. Rumboldt2; 1Tübingen/DE, 2Charleston, SC/US, 3Frankfurt/DE, 4Göttingen/DE
(iris.burck@gmx.de)
Purpose: To determine whether the relative cerebral volume measurements (rCBV)
in gliomas may serve as a surrogate or an adjunct to histopathological WHO-grading
in predicting one-year survival and recurrence.
Methods and Materials: Thirty-four patients with gliomas (WHO-grade I-IV, 27 astrocytomas) underwent CBV measurements using contrast-enhanced MR imaging.
The mean CBV value of a 6x6-pixel region of interest (ROI) and the value of a singlepixel ROI with the maximum CBV across all tumor slices were normalized relative to
the normal contralateral cerebral tissue (rCBVmean, rCBVmax). Karnofsky performance
score (KPS) and progression free survival (PFS) were recorded. Receiver Operating
Characteristic (ROC) curves and Kaplan-Meier survival analysis were conducted
separately for the CBV alone and in conjunction with WHO-grade.
Results: The rCBVmean and rCBVmax in the astrocytomas were 3.5p2.9 and 3.6p2.7.
PFS correlated with rCBV parameters (r=-0.54 to -0.56, pb0.009). WHO-grade was
correlated with rCBV values (r=0.65, pb0.0002). rCBVmax 4.2 was found to be a
significant cut-off value for recurrence prediction with 77.8% sensitivity and 94.4.%
specificity, (p=0.0001); rCBVmax b3.8 was a significant predictor for one-year survival
(93.7% sensitivity, 72.7% specificity, p=0.0002). WHO-grade was also predictor for
recurrence and one-year survival (equal p-values). The relative risk for shorter PFS
was 11.1 times higher for rCBVmax 4.2 (p=0.0006) and 6.7 times for WHO-gradeII
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Purpose: Susceptibility artifacts on T2*-weighted images appear to be valuable
in the evaluation of human astrocytic tumors. The purpose of this study was to
evaluate the use of three-dimensional (3D), high-spatial resolution susceptibilityweighted imaging (SWI), which is an emerging MR imaging technique in grading
astrocytic tumors.
Methods and Materials: A total of 21 patients (5 women and 16 men, mean
age 42.3 years) suspected of having astrocytic tumors participated in this study.
MR imaging protocol consisted of conventional MR sequences, pre-gadoliniumenhanced SWI and post-gadolinium-enhanced 3D T1-weighetd imaging. In 11cases,
post-gadolinium-enhanced SWI were also obtained. All SWI images were evaluated
qualitatively by two neuroradiologists. Astrocytic tumors were graded according to
the World Health Organization (WHO) classification. Imaging evaluation criteria
were: “old susceptibility grade” described in the past literature, hypointensity ratio
in the tumor and presence of abnormal enhancement surrounding the tumor.
Results: As a result, 18/21 cases were evaluated and 3 were excluded. Mean
grading scores of “old susceptibility grade” showed no statistical significance among
WHO grades. Mean grading scores of hypointensity ratios in the tumor were higher
for WHO grade 3 and 4 than for the rest (P = 0.05, Mann-Whitney U test). Postcontrast SWI images of 5/11 cases (WHO grade 3 and 4) showed bright enhancement surrounding the tumors due to breakdown of the blood brain barrier.
Conclusion: The use of SWI provides more information, in addition to conventional sequences, and is useful for the evaluation of astrocytic tumors in vivo, with
contrast-enhancement in particular.
Results: The PS values of low-grade and high-grade gliomas were (4.16 p 0.76) ml
100 g-1 min-1 and (11.68 p 6.09) ml 100 g-1 min-1, respectively. PS provided significant
P-value in differentiating glioma grade (P 0.001) using the Mann-Whitney U test.
PS value of gliomas had strong association with the grade of glioma, and the r value
was 0.701 (P 0.001) using the Spearman coefficient. The area under the ROC
curve was 0.923 for PS. ROC curves revealed better specificity and sensitivity in
PS for glioma grade. With a PS cut-off value of 5.13 ml 100 g-1 min-1, sensitivity was
90% and specificity was 90.9% in differentiating high- from low-grade gliomas.
Conclusion: PS value using 64-slice CT perfusion imaging provides useful information for the grade of glioma and might have the potential to significantly impact
clinical management of gliomas.
Scientific Sessions
(p=0.05). The combined CBV-WHO-grade classification enhanced the predictive
value for recurrence/progression (p 0.0001).
Conclusion: rCBV values in astrocytomas are predictive for recurrence and oneyear survival and appear to be more accurate than histopathology grading.
B-319
11:42
New WHO classification tumour entities and variants: MR-imaging features
in tumours of the posterior fossa
S. Puchner, J. Frühwald-Pallamar, G. Widhalm, J. Hainfellner, M.M. Thurnher;
Vienna/AT (stefan.puchner@meduniwien.ac.at)
Purpose: To assess the MR imaging features of newly established brain tumour
entities and variants according to the 2007 WHO classification of CNS tumours.
Methods and Materials: MR images and histological and clinical reports of
nine patients (7 male, 2 female, mean age 27 years) with a confirmed diagnosis
of rosette-forming glioneural tumour (RGNT) and medulloblastoma variants
(anaplastic and medulloblastoma with extensive nodularity) were retrospectively
reviewed. The location, signal intensities on T1- and T2-weighted DW MR images,
the presence or absence of hemorrhage or calcification, and enhancement pattern were analysed.
Results: Three RGNTs were located typically in the fourth ventricular region, whereas
one was found in the left cerebellopontine angle. A mass with multicystic appearance without perifocal edema and significant contrast enhancement was seen in 3/4
RGNTs. In one RGNT, inhomogeneous subtle enhancement was observed. Both
patients with medulloblastoma with extensive nodularity showed a central scar-like
enhancement and signs of diffusion restriction in the solid tumour parts. All three
anaplastic medulloblastoma presented as marked, inhomogenously enhancing
masses with increased signal intensity on DWI, reflecting high cellular tumour density.
Leptomeningeal spread was observed only in anaplastic medulloblastomas.
Conclusion: MRI features observed in RGNTs and two new medulloblastoma
variants are consistent with their clinico-pathological behavior. RGNTs were seen
as a multicystic, non-enhancing tumour of the fourth ventricle region, without significant edema. MRI characteristics of anaplastic medulloblastomas are consistent
with tumours of high malignancy. In medulloblastomas with extensive nodularity
a “scar-like” central enhancement was observed. Further multicenter studies with
larger patient number are necessary for valid conclusions.
B-320
11:51
Susceptibility-weighted imaging (SWI) in children with diffuse brainstem
glioma during combined anti-angiogenesis and radiation therapy
J. Sedlacik1, A. Broniscer1, U. Löbel1, F.H. Laningham1, J.R. Reichenbach2,
Z. Patay1, C.M. Hillenbrand1; 1Memphis, TN/US, 2Jena/DE (jan@sedlacik.de)
Purpose: Purpose of this ongoing study is to assess tumor angiogenesis noninvasively by using susceptibility-weighted imaging (SWI) in pediatric patients with
high-grade brainstem glioma (BG) treated with an angiogenesis inhibitor and radiation therapy (RT). SWI is sensitive to blood oxygenation and might therefore be an
early marker of response to treatment in these highly vascularized tumors.
Methods and Materials: 12 patients (age: 2-15 y) with newly diagnosed diffuse BG
were enrolled in our IRB-approved study. Patients received local RT for 6 weeks and
orally administered Vandetanib while on study. SWI data were acquired under general
anesthesia at multiple time points during therapy. Consecutive SWI data in each
patient were spatially realigned and regions-of-interest (ROI) analysis was performed
in tumor and normal appearing cerebellar white matter (WM). SWI tumor signal was
calculated relative to WM to correct for inter- and intra-subject variances.
Results: The course of the relative signal intensity (SI), averaged over all patients,
showed a significant (p=0.029) drop in tumor tissue shortly after the onset of therapy
(1.04p0.05 baseline, 0.99p0.07 after one week of treatment). This signal drop may
indicate tumor hypoxia. At subsequent follow-up measurements the SI of the tumor
returned to the baseline level.
Conclusion: SWI demonstrated a change of tumor signal during combined RT and
anti-angiogenic treatment. Whether the observed effect can be attributed to antiangiogenic therapy and/or RT cannot yet be determined due to the study design
(i.e., missing control group). However, SWI has shown to be a potential tool for
monitoring physiological changes during tumor therapy.
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Room N/O
GI Tract
SS 601b
Esophagus/Stomach: Motility and cancer
Moderators:
A.Z. Ginai; Rotterdam/NL
F. Iafrate; Rome/IT
B-321
10:30
Swallowing MR of oro-oesophageal tract and gastro-oesophageal
junction with high-speed kinetic sequences: Preliminary study in multiple
pathologic conditions
I. Sansoni, R. Del Vescovo, G. Della Longa, F. Occhicone, B. Beomonte Zobel;
Rome/IT (i.sansoni@unicampus.it)
Purpose: To evaluate the capability of high-speed kinetic MR in evaluating upper
and lower swallowing disorders.
Methods and Materials: Sixteen patients (4 males, 12 females) with various
gastro-oesophageal disorders underwent MR swallowing. MR imaging was performed on a 1.5 T magnet with high performing gradients (amplitude 30 mT/m)
with dynamic spoiled gradient echo sequences (Turbo-FLASH) acquired on three
oblique planes. The patient was studied lying in supine position, while swallowing
yogurt with paramagnetic contrast agent (1 ml of c.m./10 cc of yogurt) during observation after yogurt deglutition and during subsequent Valsalva manoeuvre. We
evaluated visualization of oesophageal bolus transit, bolus transit-time, peristalsis,
gastro-oesophageal junction patency and competency.
Results: MR imaged swallowing abnormalities in all patients: 3 with upper motility disorder,
2 with hypotonic oesophagus, 2 with achalasia, one megaoesophagus, 4 with gastrooesophageal reflux (2 of those with Hjatal Hernia), 2 after Nissen-fundoplicatio, one after
gastrectomy. MR findings well correlated with different instrumental findings.
Conclusion: High-speed kinetic swallowing MR is a useful and complementary tool
for evaluating oesophageal deglutition process and gastro-oesophageal junction
alterations. It is simple, non-invasive, rapid and well-tolerated for diagnosing GE
reflux or motility disorders, but deserves further investigations.
B-322
10:39
MR-fluoroscopy as follow-up examination in patients with achalasia after
dilatation treatment
V. Panebianco, M. Osimani, S. Bernardo, D. Lisi, E. Santucci, R. Passariello;
Rome/IT (valeria.panebianco@gmail.com)
Purpose: To evaluate the functionality and morphology of the esophagus in subjects with achalasia, who underwent pneumatic dilatation, using MR-fluoroscopy
with dynamic turbo-FLASH sequences acquired during positive oral contrast agent
administration
Methods and Materials: A total of 20 patients who underwent endoscopic pneumatic dilatation were studied using a 1.5 T magnet (Magnetom Avanto: Siemens,
Erlangen, Germany) equipped with a surface phased array coil. Dynamic imaging
protocol included turbo-FLASH sequences (TR 416; TE 1.2; FA 8°; Tck 20 mm;
FoV 350; Mat 90 x 128; N° Acq. 45; TA = 25 sec) acquired on sagittal, coronal and
axial planes during oral administration of positive contrast agent boluses (yoghurt +
Gd-DTPA 0.5 M, 1:100). We evaluated the contrast agent transit time, esophageal
clearance and esophageal lumen calibre in the two MR-fluoroscopy exams, before
and after the dilatation treatment.
Results: Good quality images were obtained in all patients, with adequate lumen
contrast and a frame rate of 2 frame/sec. All patients had a lumen reduction; in 16
patients we observed both a gain in function and better transit time ( 20 secs)
and in half the cases a complete absence of tertiary waves. In only one case did
we notice a reduction in the luminal diameter.
Conclusion: MR-fluoroscopy approach represents a promising radiation-free
modality in the follow-up of patients who underwent dilatation treatment for
achalasia.
Scientific Sessions
B-323
10:48
The performance of hydro-multidetector CT in staging of esophageal
cancer in comparison to endscopic ultrasound
S. Baroud, N. Bastati, W. Matzek, J. Zacherl, A. Poespuek, A. Ba-Ssalamah;
Vienna/AT (susanne.baroud@meduniwien.ac.at)
B-324
10:57
Pneumo-esophageal 64-MDCT: Is it worthwhile?
M. Ulla, E. Levy, M. Muñoz, D. Cavadas, A. Seehaus, R. García-Mónaco;
Buenos Aires/AR (marina.ulla@hospitalitaliano.org.ar)
Purpose: To verify the usefulness of this new CT technique in the characterization
and stratification of the esophageal wall and the periesophageal tissue.
Methods and Materials: A total of 60 patients (mean age: 64 years) with clinical or
radiological suspicion of esophageal cancer were examined with pneumo-esophageal
64-MDCT (Pn-64MDCT). To achieve esophageal distension, a 14 F Foley tube was
introduced. Continuous airflow was supplied and sustained during the acquisitions,
which were performed with a 64-MDCT scanner. Multiplanar, 3D and virtual endoscopy reconstructions were performed. A mural thickening (MT) r3 mm was considered
abnormal and reported suspicious of wall infiltration. The results were correlated with
the postoperative pathological staging of the surgical specimens.
Results: Significant distension of the esophagus (2 cm or more of diameter) including gastro-esophagic transition zone was achieved in all patients. The esophageal
lumen was visible in all its extension. In 48/60 patients (12/50 normal findings) MT
was identified. All lesions were characterized in size, shape and location. Of 60 MT,
24 were compromising the gastro-esophagic transition zone and Pn-64CT provided
better information than the endoscopy and the contrast X ray series. The correlation
with postoperative histopathological results was 90 % for MT.
Conclusion: Pn-64MDCT proved to be a useful, safe and feasible technique for
characterization and stratification of esophageal wall and periesophageal tissue.
It provided better characterization of the gastro-esophageal transition zone. It may
become a useful tool in the diagnosis and surgical planning of the esophagus and
particularly gastric cardia tumors.
B-325
11:06
Clinical significance of positive findings of lymph node metastasis
using FDG-PET for the prediction of recurrence after esophageal cancer
resection
S. Okazumi1, K. Shuto2, K. Narushima2, R. Kato1, H. Matsubara2; 1Sakura/JP,
2
Chiba/JP (sokazumi@hotmail.com)
Purpose: Currently, the amount of cancer cells in metastatic nodes is considered
to be important for the prognosis. In this study, we examined the FDG uptake of
lymph nodes of esophageal cancer cases preoperatively, estimated the cancer
amount in the metastatic lymph nodes of dissected specimen, and investigated the
relationship between FDG uptake and postoperative recurrence.
Methods and Materials: A total of 43 cases with esophageal cancer underwent
esophagectomy with three field lymph node dissection and no preoperative adjuvant
therapy. The total number of dissected nodes were 1,773, including 89 metastatic
nodes. A 370 MBq of FDG was administered and whole-body PET (GE Advance
NXi) was done before esophagectomy. Lymph node uptakes of FDG were evaluated
B-326
11:15
Preoperative T staging of gastric carcinoma obtained by MDCT vessel
probe reconstructions and correlations with histological findings
M. Moschetta, A. Stabile Ianora, A. Scardapane, M. Memeo, P. Pedote,
G. Angelelli; Bari/IT (marco.moschetta@gmail.com)
Purpose: This study aims to evaluate the diagnostic accuracy of 16-row MDCT and
vessel probe (VP) reconstructions in the T staging of gastric carcinoma.
Methods and Materials: 53 patients (39 M, 14 F, mean age 57.5) with endoscopic
diagnosis of gastric adenocarcinoma underwent CT examination. A hypotonizing
drug was administered and gastric walls were distended by the ingestion of
400-600 ml of water. A biphasic technique with 40s and 70s delay was used
after endovenous contrast medium injection. All patients underwent surgery and
preoperative and histological staging were compared.
Results: T staging diagnostic accuracy was 68% for axial images and 94% for VP
reconstructions. In the T1, T2, T3 and T4 parameter evaluation, diagnostic accuracy
values were 87, 73.5, 81 and 96%, respectively, for axial images and 96, 96, 98
and 100%, respectively, for VP reconstructions.
Conclusion: MDCT is an accurate technique for the preoperative staging of gastric cancer. The VP reconstructions obtained by isotropic data can evaluate the T
parameter with a higher accuracy.
B-327
11:24
Can CT gastrography replace double-contrast upper gastrointestinal
radiography in preoperative visualization and tumor classification of
gastric cancers?
S. Yeom, H. Ha, H. Kim, S. Park, S. Lee, A. Kim; Seoul/KR (pagoda20@hanmail.net)
Purpose: To retrospectively compare the capability of multi-detector row computed tomography (CT) gastrography with double-contrast upper gastrointestinal
series (UGIS) in the preoperative visualization and classification of pathologically
confirmed gastric cancers.
Methods and Materials: A total of 157 patients, who underwent both CT gastrography (surface shaded display images) and UGIS after obtaining a pathological
diagnosis of gastric cancer, were included in this study. All patients underwent
gastric surgeries. Based on the histopathologic results, morphologic features of
gastric cancers were classified in accordance with traditional early gastric cancer
classification and Borrmann categories for advanced gastric cancer. Two radiologists
independently evaluated the capability of CT gastrography and UGIS in visualizing
and classifying gastric cancer. Both studies were also separately reviewed without
knowledge of the results of the other study. Differences in the capability of CT
gastrography and UGI in visualizing and classifying the gastric cancers were assessed with McNemar exact test. Statistical significance was inferred at P 0.05.
Results: Histopathologically, 161 gastric cancers were identified in 157 patients,
including 67 AGCs and 94 EGCs. The capability in tumor visualization was 95.7%
(154 of 161) with UGIS and 88.8% (143 of 161) with CT gastrography (P = 0.013).
The overall accuracy for tumor classification was 62.4% (88 of 141) with UGIS and
65.2% (92 of 141) with CT gastrography (P = 0.703).
Conclusion: The capability of multi-detector row CT gastrography with surfaceshaded display images appears to be inferior to UGIS in visualizing gastric cancers,
but nearly comparable in classifying tumors.
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Purpose: To evaluate the accuracy of hydro-multidetector CT (HMDCT) in the
preoperative staging of esophageal cancer in comparison to endscopic ultrasound
(EUS) using the post operative histological results as the gold standard.
Methods and Materials: Seventy-two patients (55 male and 17 female with a medium age of 62) were included in the study. All patients underwent endoscopy with
simultaneous biopsy and histological verification of the cancer. The stomach and
esophagus were distended using 1500L of tap water and effervescent granulate.
Local tumor extension, lymph node involvement and distant metastases were assessed. From the 72 patients, 55 underwent additionally EUS. All obtained results
were compared with the postoperative histological results according to the TNM
classification.
Results: Regarding T staging, HMDCT had 54 correct diagnosis and 19 false diagnoses with a sensitivity of 76.5%, accuracy of 74% and PPV of 96%. Regarding N
staging, HMDCT had a sensitivity of 64%, specificity of 80%, and accuracy of 73%,
PPV of 72% and NPV of 72%. On the other hand, EUS had 20 right diagnoses and
35 false diagnoses regarding T staging with a sensitivity of 37%, accuracy of 36%
and PPV of 95%. Regarding N staging, EUS had a sensitivity of 72%, specificity
of 57%, an accuracy of 64%, a PPV of 57% and NPV of 73%.
Conclusion: HMDCT seems to be superior to EUS in T staging of advanced
esophageal cancer. However, EUS seems to be superior to HMDCT in staging of
T1 tumors and in N staging.
and SUVr3.0 was used as the index of preoperative diagnosis of metastatic node.
After operation, the diameter and occupying ratio of cancer cells in each metastatic
node on the pathological specimen were examined and compared with its FDG
uptake. The uptake was compared with the recurrence ratio after operation.
Results: The sensitivity, specificity and accuracy of the PET diagnosis were 95.2,
28.1 and 99.2 %, respectively. The uptakes (SUV) and the diameter occupying ratios
were significantly correlated (r = 0.47, P 0.001), and SUV 3.0 group showed
significantly higher recurrence within a year (72.9%) than SUV 3.0 group with
metastasis (30.7%; P 0.05, log-rank).
Conclusion: FDG-PET for the evaluation of lymph nodes is useful for the prediction of postoperative recurrence. The true-positive cases (sensitivity 28%) showed
significantly high recurrence and were considered to need adjuvant therapy.
Scientific Sessions
B-328
11:33
Radiologists’ performance for the differentiation between polypoid early
and advanced gastric cancers by using specific CT criteria: Emphasis on
dimpling sign
E. Lee, S. Kim, J. Lee, S. Kim, M. Kim, J. Han, B. Choi; Seoul/KR
(seraph@radiol.snu.ac.kr)
Purpose: To retrospectively determine if there are specific CT features in differentiating between polypoid early and advanced gastric cancers and to determine the
radiologists’ performance for the differentiation by using specific CT findings.
Methods and Materials: Review of medical records identified 46 patients with 27
polypoid EGCs and 19 polypoid AGCs and with CT scans available for review. Two
radiologists retrospectively reviewed CT studies regarding the presence and degree
of dimpling at tumor base, the presence of vessel invagination at the dimpling site,
thickening of low-attenuating outer layer, perigastric infiltration, and transmural fullthickness enhancement of the lesion. Individual CT findings relevant as predictors
were determined using the univariate and multivariate analyses. Individual review
of CT scans was then performed by two other radiologists who were blinded to the
diagnosis and were known to the results of univariate and multivariate analyses.
Individual performance was evaluated by means of ROC analysis.
Results: The presence of 3.5 mm severe dimpling at the base of the tumor (31.3)
achieved highest odds ratio for the differentiation and followed by vessel invagination
(12.3), the presence of dimpling (9.8), perigastric infiltration (5.2), and transmural
full-thickness enhancement (4.8). Multivariate analysis showed the presence of
3.5 mm severe dimpling was the only independent variable that differentiated
polypoid AGCs from EGCs. The individual accuracy of differentiation using significant CT findings was very good, with AZ values of 0.827 and 0.811.
Conclusion: More than 3.5 mm dimpling and other ancillary CT findings are helpful in differentiating between polypoid AGC and EGC and allow good individual
accuracy for the differentiation.
B-329
Purpose: To evaluate the feasibility of automated CT volumetry for prediction of
pathologic response to neoadjuvant chemotherapy of malignant lymph nodes (LNs)
in advanced gastric cancer (AGC) patients.
Methods and Materials: A total of 36 patients with resectable AGCs (stage
rT2N1), treated with neoadjuvant chemotherapy and radical gastric resection,
were prospectively enrolled in this study. Before and after chemotherapy, contrastenhanced MDCT was obtained. One radiologist determined the largest LN as the
index node (iLN) on pre-chemotherapy CT. The surgeon carefully dissected the
iLN. Two pathologists determined the pathologic response of the node on a fivepoint-scale. The longest diameter, area and volume of iLN were calculated using
automated volumetry software (Syngo CT Oncology, Siemens). Initial automated
segmentation quality was analyzed on a four-point scale and the number of verifications was recorded. Additionally, radiologists manually measured the longest
diameter of iLN. For all 36 iLNs, percentage diameter, area and volume reduction
rates were calculated and correlated with pathologic regression grades.
Results: Mean score of initial automated segmentation quality for 72 iLNs (each 36
on pre- and post-chemotherapy CT) was 3.4 p 0.67, 49 (68.1%) with initial segmentation scores of r3 not requiring additional verification. For the remaining 23 iLNs,
the mean number of verification was 1.43. Among the four measurement methods,
percentage reduction rates for automatically calculated area and volume showed
significant correlation with pathologic regression grades. Correlation coefficient was
highest in the percentage volume reduction rate (r = 0.434, P = 0.008).
Conclusion: Automated CT volumetry is technically feasible for assessment of
LNs. Automated CT volumetry for iLNs is the most accurate tool in the prediction
of histopathologic response following neoadjuvant chemotherapy in AGC.
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Evaluation of 18 F-FDG PET in advanced gastric cancer: A comparison
with CT and surgical histopathology
H. Kim, D. Choi, J. Hwang, S. Hong, Y. Kim; Seoul/KR (mogrry@daum.net)
Purpose: To retrospectively compare 18 F-FDG PET with abdominal CT for
advanced gastric cancer (AGC) by using surgical histopathology as the reference
standard.
Methods and Materials: Surgical specimens were obtained from 21 (14 men, 7
women; mean age 54.9 years) of 49 patients with AGC. Preoperative PET and CT
were reviewed for primary tumors and lymph node metastases as compared with
surgical histopathology and lymph node dissection. The regional lymph nodes were
classified according to the Japanese Research Society for Gastric Cancer.
Results: Values for well-differentiated and moderately differentiated versus poorly
differentiated adenocarcinoma and signet ring cell carcinoma were 2.69 versus
2.66 (P = 0.970) for the primary lesion (SUV = 2.56) and 1.76 versus 3.81 for the
lymph nodes. There were 7 patients (33.3%) without lymph node metastases, 11
(52.4%) in compartment I and II and 3 (14.3%) in compartment III and IV on CT
(kappa value = 0.227, P = 0.045); 18 (85.7%), 2 (9.5%) and 1 (4.8%) patient on PET
(kappa value = 0.128, P = 0.189); 9 (42.9%), 2 (9.5%) and 10 (47.6%) patients on
histopathologic specimens. The overall lymph node detection rate was significantly
higher for CT (66.7%) versus PET (14.3%) in operable AGC.
Conclusion: 18 F-FDG PET is accurate for primary tumor detection and SUVs
for poorly differentiated types were significantly lower than for highly differentiated types of primary lesions and lymph node metastases. 18 F-FDG PET and
CT were less sensitive to N staging of AGC and underestimated lymph nodes in
compartment III and IV.
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Interventional Radiology
11:42
Feasibility of automated CT volumetry for neoadjuvant chemotherapy
monitoring of malignant lymph nodes in advanced gastric cancer: A
prospective study
M. Yu, S. Kim, J. Goo, J. Lee, J. Lee, J. Han, B. Choi; Seoul/KR
(whynot@radiol.snu.ac.kr)
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Carotid and intracranial interventions
Moderators:
S. MacDonald; Newcastle upon Tyne/UK
L. Pierot; Reims/FR
B-331
10:30
Eight years of experience in carotid artery stenting with cerebral
protection device
F. Fanelli, E. Boatta, P. Rabuffi, A. Pucci, M. Allegritti, R. Passariello; Rome/IT
Purpose: To evaluate the results and the technical aspects of eight-year experience in carotid artery stenting (CAS) performed with cerebral protection devices
in order to prevent thromboembolic complications.
Methods and Materials: From February 2000, 314 patients with internal carotid
artery stenosis underwent carotid artery stenting (331 procedures were performed).
There were 213 men and 101 women (age 65-87 years, mean 71.4 y). One-hundredtwenty-one patients were symptomatic with stenosis 50% and 193 were asymptomatic with stenosis 80%; 282 primary stenosis and 49 stenosis secondary to TEA
were treated. Seventeen patients underwent bilateral stenting. Cerebral protection
devices were used in 314 cases; 17 cases (5.1%) were performed without cerebral
protection. All cases were performed using self-expandable stents. Cerebral DWMRI examination was also performed before and after the procedure to evaluate
neurological complication occurred during CAS.
Results: Technical success (residual stenosis 30%) was obtained in all cases
(100%). The mean follow-up was 26.5p15.8 months. Thirty-days mortality was
1/314 cases (0.3%). One year mortality was reported in 2/314 cases (6.3%). Six
major complications were observed (1.8%): 3 periprocedural major strokes (0.9%)
and 3 post-procedural (within 3 days) major strokes (0.9%). In 21 cases (6.3%),
embolic material was found inside the cerebral protection. In 4 cases, a moderate
itra-stent restenosis was observed (1.2%) and treated with angioplasty in 2 cases
with angioplasty and re-stenting in the other two cases.
Conclusion: CAS represents a feasible procedure that can be performed in highrisk patients and it is associated with a low restenosis rate.
Scientific Sessions
B-332
10:39
Comparison of stent free cell area and cerebral lesions after carotid artery
stent placement
I.Q. Grunwald, K. Karp, W. Reith, P. Papanagiotou, C. Krick; Homburg a.d. Saar/DE
(i.grunwald@web.de)
B-333
10:48
Influence of stent preparation on embolic complications during carotid
artery stenting
S.M. Pilgram, P. Weber, A.M.J. Frölich, A. Mohr, M. Knauth; Göttingen/DE
(s.pilgram@med.uni-goettingen.de)
Purpose: Carotid angioplasty and stenting (CAS) is a well established method for
the prevention of ischemic stroke. Although CAS can be performed with acceptable
complication rates, the risk of periprocedural embolization is relatively high. In this
study, we investigated the influence of stent preparation and duration of intervention on
microembolic events during CAS, as detected by diffusion-weighted imaging (DWI).
Methods and Materials: Prospective study of 47 patients with high grade or symptomatic carotid stenosis undergoing CAS. To detect new DWI lesions, MRIs were
performed 24 hours before and after intervention. In a subgroup of patients (n=8),
we pre-deployed approx. 70% of the stent (Carotid Wallstent®, Boston Scientific) in
a basin containing heparinized sterile isotonic saline. Duration, subjective degree
of difficulty and number of contrast injections during the CAS procedure were also
analysed and correlated to the occurrence of new DWI lesions.
Results: In the subgroup (n=8) where stents were pre-deployed, significantly less
new DWI lesions were detected when compared to standard stent preparation
(1.13 vs. 4.15, p=0.012). Regarding procedural duration and difficulty, we found
that patients without detectable microembolic events had a significantly lower mean
number of contrast injections (6.74 vs. 5.59, p=0.036).
Conclusion: Our results suggest that pre-deployment of stents, prior to implantation, can significantly lower the rate of DWI lesions associated with CAS. This may
be explained by air microbubbles remaining within the stent cells, which cannot be
eliminated with standard preparation procedures. In addition, reducing the number
of contrast injections may further decrease periprocedural complications.
B-334
10:57
Reperfusion syndrome after carotid stent angioplasty
I.Q. Grunwald, M. Politi, P. Papanagiotou, W. Reith, M. Essig; Homburg a.d. Saar/DE
(i.grunwald@web.de)
Purpose: This study assesses the incidence and significance of hyperperfusion
syndrome occurring after CAS.
Methods and Materials: We retrospectively reviewed the prospective database of
417 consecutive patients who were treated with CAS in our department to identify
patients who developed hyperperfusion syndrome and/or ICH. MR imaging including
FLAIR and diffusion weighted imaging was acquired before and after CAS in 269
cases. A Spearman’s Rho non-parametric correlation was performed to determine whether there was a correlation between the occurrence of hyperperfusion
syndrome and patients’ age, degree of stenosis on the stented and contralateral
side, risk factors such as diabetes, smoking, hypertension, adipositas, gender
B-335
11:06
Technical success rates, procedural complications and clinical outcome in
stenting of intracranial stenoses
F. Brassel1, S. Schotes1, D. Meila1, M. Nolden-Koch1, K. Papke2; 1Duisburg/DE,
2
Lingen/DE (f.brassel@klinikum-duisburg.de)
Purpose: To evaluate technical and clinical success rates of stenting for intracranial stenoses.
Methods and Materials: 53 patients were treated with 56 intracranial stents.
Indications for stent placement were established in interdisciplinary consensus
(neurology and neuroradiology). Procedural success parameters were the successful stent deployment, absence of procedural complications and absence of
residual stenosis 50%. Clinical success was defined by applying the NIH stroke
scale prior to the intervention and before discharge.
Results: 53 stents were deployed; in three cases, the stenosis could not be reached
with the microcatheter. Procedural complications were 3 minor dissections, 2 severe
dissections, 1 subarachnoid hemorrhage, 1 intracranial hemorrhage and 3 vasospasms. Clinical outcome was favourable in 51 patients with NIH score at discharge
better or equal compared to prior to the intervention. One patient suffered a minor
stroke two days after the intervention. One patient with stenting died as a result of
severe intracranial reperfusion bleeding 4 days after the procedure.
Conclusion: If performed in an interdisciplinary setting, intracranial stenting has
a high technical and clinical success rate. Further follow-up is warranted to define
long term results of intracranial stenting.
B-336
11:15
Endovascular occlusion of wide-necked aneurysms with stenting and
coiling
J. Sedat1, Y. Chau1, J. Szapiro2, L. Mondo1, M. Chassang1; 1Nice/FR, 2Bastia/FR
(jsedat@yahoo.fr)
Purpose: To present our single-center experience with endovascular treatment
of wide-neck intracranial aneurysms using Neuroform stent associated with coiling, and to evaluate complications, effectiveness, and long-term results of this
technique.
Methods and Materials: A study of 42 patients with wide-necked cerebral aneurysms treated with a Neuroform stent was performed. Mean aneurysm neck size
was 5.33 mm. There were 31 unruptured aneurysms (74%), and 11 aneurysmal
subarachnoid hemorrhages (26%). Clinical and angiographic follow-up was available in 38 patients (90.5%). The overall follow-up time ranged from 6 months to
5 years (mean 42 months), but most of the patients (92%) had a follow-up period
superior to 1 year. Apart from 3 cases with only 6 months-angiographic-follow-up,
the angiographic follow-up was superior to 1 year for the others (92%).
Results: Successful deployment of 41 stents for 42 aneurysms (97%) was obtained.
Procedural complications were observed in seven cases (16.5%), but permanent
procedural morbidity was observed in one patient (2.4%). Long term complete
aneurysmal occlusion was obtained in 27 patients (71%). Aneurysmal regrowth
was observed in 4 patients (9.5%) on the first control angiogram. After the first
control angiogram, no delayed recanalization or regrowth was observed. During
the follow-up period, one patient presented a moderate and asymptomatic stenosis
into the stent; there were no events of hemorrhage, no delayed thrombosis and no
stent displacement, fracture or torsion.
Conclusion: These results show effectiveness of the technique, small rate of
procedural complications, and long-term tolerance to the Neuroform stent.
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Purpose: This study examines whether there exists a correlation among closed,
semi-closed and open-cell stent design and cerebral ischemic lesions identified
by diffusion-weighted magnetic resonance imaging (DW-MRI) after carotid artery
stenting (CAS).
Methods and Materials: A retrospective review was conducted on a nonrandomized cohort of 194 patients treated with CAS and evaluated by cerebral DWI before
and after the intervention. The mean age of these patients was 68.0 p 0.6 years and
the mean degree of stenosis on the dependent side was 87.2% p 0.7. Three stent
designs were studied: closed-cell (Wallstent), semi-closed-cell (Smart) and open-cell
(Zilver). A non-parametric correlation (Spearman's Rho) was performed between
the stent free cell area and the number and area of ischemic lesions found after the
intervention. Adverse events and neurological assessment were evaluated.
Results: A significant correlation was found between the stent free cell area and
the number and area of new cerebral ischemic lesions detected on DW-MRI (P =
0.023). There were significantly fewer new lesions with an open cell design (Zilver;
12.76 mm² free cell area) than with a closed cell design (Wallstent; 1.08 mm² free
cell area). However, there was no significant difference in clinical outcome between
the three stent groups.
Conclusion: Open-cell stent design is related to fewer cerebral ischemic lesions
after CAS. However, clinical outcome, measured by incidence of adverse events
and clinical neurologic assessment, is not significantly different between patients
with different stent designs.
and fluoroscopy time, mean area of postprocedural lesions as well as preexisting
lesions. Significance was established at P 0.05.
Results: Of the 417 carotid arteries that were stented and received MRI, we
found a hyperperfusion syndrome in 2.4% (10 cases). Patients with pre-existing
brain lesions (old or fresh stroke) were more at risk to develop a hyperperfusion
syndrome p=0.022 (Spearman-Rho-test). We could not show any correlation to all
other patient characteristics.
Conclusion: We could not confirm that older patients with hypertension and
impaired hemodynamic reserve are the highest risk situation for developing hyperperfusion syndrome after stent placement. However, there might be a correlation between pre existing brain lesions such as old territorial infarcts and freshly
demarked lesions.
Scientific Sessions
B-337
11:24
Neurointerventions in giant aneurysms: Results in 25 cases
L. Karanam, R. Kamble, S. Grahadurai, S. Joseph; Chennai/IN (drklsp@gmail.com)
Purpose: To study efficacy of endovascular management in intracranial giant
aneurysms.
Methods and Materials: The period of study is 5 years and 5 months (Feb 2003-July
2008) which included 25 patients (7M/18 F, age group 9 to 76 yrs) who presented
with symptoms of mass effect, SAH, ICH and infarct. CT/CTA/MRA/DSA done in
all patients before treatment, cross compression test done in all patients, BOT
done in 13 patients. Patients underwent treatment with parent vessel occlusion,
stent assisted coiling, balloon assisted coiling, stent graft, ONYX, stent and ONYX
depending on the findings. Clinical and angiographic follow-up done at intervals of
1, 3, 6, 12, 24 and 48 months.
Results: 84% (21) of giant aneurysms are found in anterior circulation (supraclinoid ICA-4%, carotid ICA-36%, caroticopthalmic ICA-40%, pcom-4%) and 16%
(4) in posterior circulation (basillar-12%, vertebral-4%). Total occlusion is seen in
76% (19) of the cases and partial occlusion in 28% (7) of the cases. Worsening of
mass effect seen in 12% (3) of the cases, ICH in 8% (2), thromboembolic events
in 12% (3) and vasospasm in 12% (3). Temporary neurological defecits seen in 6
patients and permanent deficits in 3 patients. Death occurred in one patient. On
follow-up improvement in mass effect seen in 23 patients (92%) and recanalisation seen in 2 patients (8%) managed conservatively. Mortality rate is 4.0% and
morbidity is 16.0%.
Conclusion: Endovascular treatment can be the treatment of choice with promising
results and acceptable risk in the treatment of giant aneurysms. Treatment with stent
assisted coiling, balloon assisted coiling, onyx rather than coiling alone appears to
be the best treatment option in giant aneurysms.
B-338
11:33
Onyx embolisation of cerebral arterior venous malformations
A.K. Gupta, A. Hr, N.K. Bodhey, S.N. Patro, H.S. Pendharkar; Trivandrum/IN
(gupta209@gmail.com)
Purpose: To study the efficacy of Onyx embolisation in cerebral AVMs
Methods and Materials: Between March 2006 and August 2008, 45 patients with
brain AVMs were embolized with Onyx. Patients included 24 males and 21 females
with mean age of 28 years (range 10-52 years). Clinical presentation included
intractable seizures in 30, parenchymal and intraventricular hemorrhage in 8, SAH
from concomitant aneurysm in 1, motor aphasia in 1 and intractable headache in
5 patients. Average Spetzler-Martin grade and AVM volume at presentation was
3 and 18 cm3 respectively.
Results: Fifty-nine Onyx embolisation procedures were performed in these patients.
A total of 138 feeding pedicles were embolized, averaging 2-3 pedicles per patient.
Intra-nidal fistulas were embolized with varying concentration of NBCA. Average
estimated size reduction was 75% (range 10-100%). Total angiographic obliteration
was achieved in 8, partial embolisation followed by radiosurgery in 25 (90-95%
obliteration in 10 and 80-90 % obliteration in 15 patients), partial embolisation
followed by surgery in 1, and 11 patients have been advised additional sittings of
embolization. Complications occurred in 10 patients, 4 had transient neurological
deficits, one each had intraventricular, small parenchymal haematoma and cortical
vein thrombosis. Three patients had post embolisation parenchymal haematoma
that was surgically evacuated. No mortality was documented.
Conclusion: Onyx is a safe new liquid embolic agent for the embolisation of brain
AVMs. Complete obliteration can be achieved in small AVMs. Large AVMs can be
adequately reduced in size for additional surgical/radiosurgical treatment.
B-339
11:42
Endovascular management of direct carotico-cavernous fistula: Long term
follow-up
A.K. Gupta, N.K. Bodhey, H.S. Pendharkar, S.N. Patro, A.L. Periakaruppan;
Trivandrum/IN (gupta209@gmail.com)
Purpose: To evaluate the therapeutic benefits and long term follow-up of endovascular management of direct carotico cavernous fistulae (CCF).
Methods and Materials: A total of 97 treated direct CCFs in last 11 years were
retrospectively studied. Follow-up was available in 56 patients (from 10 years to 3
months). Forty-four were males and 12 females, age range 6-65 years (mean 30).
The etiology was trauma in 49, spontaneous in 6 and iatrogenic in 1 patient. Presentations included headache, pain, proptosis, chemosis, diplopia, visual deficits,
tinnitus etc. Baseline work-up included neck vessel Doppler & TCD studies, brain
CT/MRI in addition to routine blood investigations and cardiological evaluation.
Complete cerebral DSA was performed and site of the fistula was demonstrated with
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vertebral angiogram and ipsilateral carotid compression. Selective catheterization
of the fistula was followed by deployment of balloons, coils or combination.
Results: Complete obliteration of the fistula was achieved in 53 (89.83%), moderate
filling in 2 (3.38%) and mild residual filling in 4 (6.77%). Significant symptomatic
relief was still seen in these patients. Complications included minor ones as balloon
deflation and migration in 4, failure of coil detachment in one & major complications
as dense hemiplegia in two, and death of four patients (3 with connective tissue
disorder and 1 with cortical venous rerouting).
Conclusion: Endovascular treatment remains the treatment of choice for effective
long term occlusion of CCFs.
B-340
11:51
Effect of type of fistula and various embolic materials on the outcome of
intracranial dural arteriovenous fistula: Analysis of 73 patients
S.N. Patro, A.L. Periakruppan, A.K. Gupta, N.K. Bodhey, H.S. Pendharkar;
Trivandrum/IN (drsatyanpatro@gmail.com)
Purpose: (1) To analyze the treatment outcome according to the type of DAVF
and the embolic material used. (2) To analyze the types of DAVF with aggressive
presentation.
Methods and Materials: We investigated 73 consecutive patients with mean age
56.3 years, who were diagnosed to have dural arterio venous fistula. According
to the five types as described by Cognard, it was classified. Each type was angiographically analyzed for the various aggressive presenting factors. Depending on
the type, it was managed and embolized by different materials and routes.
Results: Out of all cases, type I fistula was noted in three patients (4%), type IIa
in twenty eight (39%), type IIb in seven (9.5%), type IIab in nineteen (26%), type III
in six (8%), type IV in nine (12%) and type V in one patient (1%). Transarterial was
the most common route used (nearly 40% cases). Fistulae were obliterated with
various embolic materials like PVA, onyx, coils, NBCA and alcohol; either single or
in combination. Aggressive presentation was significantly associated with presence
of venous ectasia and cortical venous reflux on angiograms. Use of combination
of embolic materials had better results. Lower grade (up to IIb) had a favorable
outcome. Overall mortality rate was 6.8%.
Conclusion: The type of dural AVF, venous ectasia and cortical venous reflux are
primary determinants for aggressive presentation. Combination of embolic materials
with preservation of sinuses will be the optimal method of endovascular therapy.
10:30 - 12:00
Room R
Cardiac
SS 603b
Myocardial perfusion
Moderators:
K. Gruszczynska; Katowice/PL
R. Rienmüller; Graz/AT
B-341
10:30
Assessment of myocardial perfusion in rats: Validation of spin-labeling
gradient echo imaging against fluorescent microsphere technique as
standard of reference
A. Jacquier, F. Kober, S. Bun, P.J. Cozzone; Marseille/FR (frank.kober@univmed.fr)
Purpose: The purpose of this study was to determine the accuracy of arterial spin
labeling gradient echo imaging (ASLGRE) in measuring myocardial perfusion in rats
using a fluorescent microsphere technique as standard of reference.
Methods and Materials: Male Wistar rats (weight = 200-240 g, n = 16) were
anesthetized with 2.1% Isoflurane added to1 l/min of pure O2; their heart rate,
breathing rate, temperature, O2 saturation and arterial blood pressure were recorded. Myocardial perfusion was assessed in 8 rats on a Bruker, Biospec 4.7T
(Bruker, Ettlingen, Germany) using an ECG and respiration-gated IR gradient-echo
technique (resolution = 234 × 468 µm², TE/TR = 1.52/ms, slice thickness 3 mm,
sequence duration 25 min at 350 bpm). In the control group (n = 8) myocardial
perfusion was assessed using a fluorescent microsphere technique (under 1 l/
min 100% O2): A mixture containing 100,000 fluorescent microspheres (Yellow,
15 p 0.1 µm; Triton, San Diego, CA, USA) was injected into the left ventricle. The
animals were killed and heart, and blood samples were harvested. The samples
were processed and fluorescence was measured.
Scientific Sessions
Results: There were no significant differences between the groups in terms of heart
rate (400 p 20 bpm), breathing rate (50 p 12/min), temperature (36.9 p 0.1), O2 saturation (98 p 1%) or mean blood pressure (9.8 p 0.3 mmHg). There were no statistical
differences in myocardial perfusion assessed using ASLGRE (6.5 p 1.4 ml/g/min)
and using the fluorescent microsphere technique (5.9 p 2.3 ml/g/min; P = 0.5). The
fluorescent microsphere technique provides measurements of left ventricular stroke
volume (179 p 63 µl/beat), cardiac index (348 p 133 ml/min.kg), total peripheral
resistance (0.32 p 0.1 mmHg.min.kg/ml).
Conclusion: ASLGRE provides reliable, high-resolution myocardial perfusion
measurements.
B-342
10:39
MR perfusion of the myocardium: Semiquantitative and quantitative
evaluation in comparison to coronary angiography and intracoronary
pressure wire examination
A.M. Huber, S. Sourbron, J. Rieber, J. Schäfer, K. Bauner, M.F. Reiser; Munich/DE
(armin.huber@roe.med.tu-muenchen.de)
B-343
10:48
Quantification of left ventricular function, perfusion and viability in chronic
microinfarction using multidetector computed tomography, magnetic
resonance imaging and histochemical staining
M. Carlsson, D. Saloner, A. Martin, C. Stillson, M. Saeed; San Francisco, CA/US
(marcus.carlsson@med.lu.se)
Purpose: To compare 64-slice multidetector computed tomography (MDCT) with
magnetic resonance imaging (MRI) and histopathology in quantifying microinfarction
and assessing its long-term effects on myocardial perfusion and LV function.
Methods and Materials: An XMR-suite was used to catheterized the LAD coronary artery under X-ray and to define the LAD-territory using first-pass MRI during
intracoronary injection of 10% Gd-DOTA. The perfusion territory was selectively
embolized in six pigs using a small embolic agent (40-120 µm, 250,000 count). At
7-8 weeks after microembolization, LV function, first-pass perfusion and delayed
contrast enhancement imaging were performed using MDCT and MRI. Histochemical staining (TTC) was used for quantification of microinfarction.
Results: The LAD-territory was 32p4% of the LV. There was no significant difference between MR and MDCT measurements of systolic wall thickening at
7-8 weeks. Global LV function did not differ between MRI (end diastolic volume:
92p8 ml, end-systolic volume 48p5 ml and ejection fraction: 47p3%) and MDCT
(96p8 ml, 49p3 ml, 49p2%, respectively). MRI detected a perfusion deficit in the
embolized territory (significant decrease in max upslope, max signal intensity and
longer time to the peak compared to remote), which was not detected by MDCT.
Microinfarction size did not differ between MDCT (6.3p0.8% LV), MRI (6.6p0.5%
LV) or TTC (7.0p0.6% LV).
Conclusion: Modern MDCT and MRI techniques have the sensitivity to quantify
chronic microinfarction and demonstrate its effect on LV function. However, MRI is
more sensitive than MDCT in the detection of perfusion abnormalities in chronic
microinfarction.
10:57
Volumetric quantification of myocardial perfusion using analysis of
multidetector-computed tomography 3D data sets: Comparison with
nuclear perfusion imaging
N. Kachenoura1, F. Veronesi2, J. Lodato1, C. Corsi2, R. Mehta1, B. Newby1, R. Lang1,
V. Mor-Avi1; 1Chicago, IL/US, 2Bologna/IT (nadjia.kachenoura@gmail.com)
Purpose: The detection of perfusion abnormalities associated with myocardial
infarction (MI) from multi-detector computed tomography (MDCT) images is based
on visual interpretation of selected 2D slices. We sought to develop a technique
for quantitative 3D analysis of myocardial perfusion and test it against SPECT
myocardial perfusion imaging (MPI) reference.
Methods and Materials: We studied 44 patients undergoing CT coronary angiography (CTCA): 15 controls and a study group of 29 patients that included 15
patients post MI. MDCT data sets acquired for CTCA were analyzed using custom
software to generate a bull’s eye display of myocardial perfusion and calculate a
quantitative index of extent and severity of perfusion abnormality, QH, for 16 volumetric segments. Visual interpretation of MDCT-derived bull’s eyes was compared
with resting MPI scores on a segment, coronary and patient basis. Quantitative
MDCT perfusion data were correlated with rest MPI summed scores and used for
objective detection of perfusion defects.
Results: MDCT-derived bull’s eyes accurately reflected perfusion defects in agreement with MPI (kappa = 0.70 by territory; 0.79 by patient). Quantitative data agreed
with MPI: (1) correlation between summed QH and MPI scores: 0.87 (territory), 0.84
(patient); (2) area under ROC curve 0.87; sensitivity 0.79-0.92, specificity 0.83-0.91,
accuracy 0.83-0.89 for objective detection of abnormalities.
Conclusion: Our technique for volumetric analysis of MDCT images is feasible
and allows accurate objective detection of fixed perfusion defects. Because perfusion information may aid in elucidating the significance of coronary lesions and
can be obtained without additional radiation or contrast load, this technique may
prove clinically useful.
B-345
11:06
Adenosine stress dual energy CT of the heart for diagnosing myocardial
ischemia and viability compared with cardiac MRI and SPECT: Initial
experience
B. Ruzsics, Y. Lee, P. Zwerner, S. Chiaramida, P. Costello, U.J. Schoepf;
Charleston, SC/US (ruzsics@musc.edu)
Purpose: To evaluate the feasibility of adenosine-stress and delayed enhancement
dual energy CT (DECT) for diagnosing fixed/reversible myocardial ischemia and
viability compared with cardiac MRI (cMRI) and SPECT.
Methods and Materials: A total of 15 patients with known or suspected coronary
artery disease underwent: 1) adenosine stress/rest SPECT; 2) adenosine stress/rest
perfusion and delayed enhancement cMRI; 3) adenosine stress/rest and delayed
enhancement DECT on a dual-source CT system in dual energy mode (A-tube:
140 kV, B-tube: 100 kV). In each patient all three DECT data sets were analyzed
for myocardial contrast deficits and delayed enhancement by mapping the iodine
content within the myocardium based on different X-ray spectra. Two independent
observers evaluated SPECT, cMRI and DECT for fixed/reversible ischemia and
cMRI and DECT for delayed enhancement.
Results: All patients were successfully imaged with all three modalities. A total
of 255 myocardial segments were analyzed, of which 56 were abnormal at cMRI.
Interreader agreement for detection of fixed/reversible ischemia and delayed enhancement at DECT was moderate to excellent (k = 0.5 to k = 1). Compared with
cMRI, DECT and SPECT had 100% (88%) sensitivity, 99% (96%) specificity and
99% (97%) accuracy for detecting fixed perfusion defects, respectively. Reversible ischemia was detected with 100% (100%) sensitivity, 100% (90%) specificity
and 100% (92%) accuracy. Compared with cMRI, DECT-detected myocardial
segments showing delayed enhancement with 100% sensitivity, 100% specificity
and 100% accuracy.
Conclusion: Adenosine stress and delayed enhancement DECT are feasible
modalities. Compared to cMRI as the reference standard, DECT shows good
agreement for delayed enhancement and equal or better peformance than SPECT
for detection of myocardial ischemia.
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Purpose: To investigate, if a stress examination alone achieves comparable diagnostic accuracy, as a stress and rest examination does, if a quantitative evaluation
is used instead of a semiquantitative evaluation.
Methods and Materials: A total of 31 patients with CAD underwent 1.5 T MRI
and coronary angiography (CA). Stenosis between 50 % and 75 % were evaluated
by an intracoronary pressure wire examination (FFR) for their relevance. Signalintensity-time curves of the first pass MR perfusion images (SR-turboFLASH,
stress/rest) were analysed by Argus DSA. For the semiquantitative evaluation the
upslope value (US) of a linear fit from the foot point to the signal maximum was
calculated for 18 segments. For the quantitative evaluation a model independent
deconvolution was used to calculate myocardial blood flow (MBF). US and MBF
were determined for each segment for stress and rest. The ratio of the stress and
rest value for each segment was determined (MPRI). Coronary artery stenosis
75% or 50% with positive FFR 0.75 were considered as hemodynamically
relevant. ROC curves were calculated.
Results: The values of the area under the ROC curves (AUC) were 0.78, 0.56
and 0.92 for the USStress, USRest and USMPRI evaluation (semiquantitative evaluation).
The values for the MBFStress, MBFRest and MBFMPRI (quantitative evaluation) were
0.92, 0.68 and 0.84, respectively. Comparing USMPRI and MBFStress, no significant
difference was found (p 0.001).
Conclusion: The quantitative model provides identical diagnostic performance, if
only a stress examination is used, as a semiquantitative evaluation of stress and
rest examination does.
B-344
Scientific Sessions
B-346
11:15
k-t SENSE accelerated stress myocardial perfusion MRI at 3 Tesla
S. Kato, H. Sakuma, M. Nagata, N. Ishida, K. Kitagawa, M. Ishida, H. Nakajima;
Tsu/JP (shingo.y03129@gmail.com)
Purpose:To evaluate the feasibility and diagnostic accuracy of high spatial resolution stress myocardial perfusion MRI acquired at every heartbeat by using k-t
SENSE and 3 Tesla MR imager.
Methods and Materials: A total of 31 patients with suspected coronary artery
disease (CAD) were studied. High spatial resolution ( 2 mm) first-pass contrastenhanced MR images were obtained at rest and during stress by using 3.0 T MR
imager and k-t SENSE acceleration factor of 5. Saturation recovery TFE images
were acquired with TR/TE of 1.5 ms/2.9 ms, FOV = 40 x 30 cm, matrix = 256 x
192, slice thickness = 8 mm. Three short-axis sections of the LV were imaged at
every heartbeat. Two observers determined the image quality score (1: poor to
4: excellent) and recorded the presence or absence of respiratory artifacts and
endocardial dark rim artifacts using a 16-segment model. Coronary angiography
was performed in 12 patients within 2 weeks of stress perfusion MRI.
Results: All studies were successfully completed, with the average image quality
score of 3.8 p 0.4. Endocardial dark rim artifacts were observed in 17 (3.4%) of
496 segments, but there were no cases in which dark rim artifacts influenced the
diagnosis. Respiratory artifacts were found in 11 (2.2%) of 496 segments. The
sensitivity, specificity, positive and negative predictive values and accuracy of stress
perfusion MRI for detecting significant CAD were 87.5% (7/8), 96.4% (27/28), 87.5%
(7/8), 96.4% (27/28) and 94.4% (34/36).
Conclusion: High spatial resolution perfusion MRI can be acquired at every
heartbeat by using 3 T MR imager and k-t SENSE acceleration. This approach can
substantially reduce endocardial dark rim artifacts and allow accurate detection of
myocardial ischemia in patients with significant CAD.
B-347
11:24
Dose response of the intravascular contrast agent gadofosveset trisodium
in MR perfusion imaging of the myocardium
A.M. Huber, S. Niedermayr, M. Prompona, C. Cyran, M.F. Reiser; Munich/DE
(armin.huber@roe.med.tu-muenchen.de)
Purpose: To evaluate the response of gadofosveset (3 doses) in healthy volunteers
concerning contamination of a second perfusion scan and saturation effects in
the input curve.
Methods and Materials: 18 volunteers were examined at 3.0 T using a SRturboFLASH sequence. MR first pass perfusion imaging at rest was performed twice per
volunteer with a break of 5 minutes. 3 dose groups were investigated: 0.015 mmol/kg
(1), 0.0075 mmol/kg (2) and 0.00385 mmol/kg (3) per perfusion scan. Mean values
of the baseline and of the signal maximum derived from the signal-time curves
(Argus, DSA) in the myocardium and the left ventricular cavity were determined. $
SI values were determined between baseline and signal maximum.
Results: Mean values for the baseline in the myocardium for the first/second
perfusion scans were 8.9/16.4, 9.2/13.5 and 8.7/10.9 for groups 1, 2 and 3. Mean
baseline values for the LV cavity were 6.9/27.0, 6.8/16.9 and 6.3/10.5. Mean values
for the signal maximum in the myocardium were 16.4/20.8, 13.5/16.6 and 10.9/12.9.
Mean values for the signal maximum in the LV cavity were 86.7/93.8, 58.7/70.8 and
30.5/35.7 for groups 1, 2 and 3. $ SI showed no significant differences between the
first and second perfusion scans for the myocardium and no significant difference
in the LV cavity in groups 2 and 3; however, there was a significant difference in
group 1 (p 0.05).
Conclusion: Contamination of the myocardium plays a minor role in the myocardium; however, saturation effects have an influence on the LV cavity at a dose of
0.015 mmol/kg.
B-348
11:33
Perfusion defects in postmenopausal women with micro-vascular angina:
An MRI study
F. Fiocchi, G. Ligabue, R. Rossi, A. Nuzzo, M. Modena, P. Torricelli; Modena/IT
(federica.fiocchi@gmail.com)
Purpose: Coronary microcirculation abnormalities have shown to play a role in
patients with typical angina and no coronary stenosis (micro-vascular angina).
Recent data on women show that these patients may have transient myocardial
perfusion abnormalities in response to stress-test. If these perfusion defects are
also present at rest, as indicator of microcirculation damage has not been fully
investigated and represents the aim of this study.
Methods and Materials: We recruited 17 postmenopausal women (mean age
57.6 p 8.7) with typical angina without significant coronary artery disease at
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coronary angiography (defined as no or minimal luminal narrowing). Each patient
underwent first-pass perfusion cardiovascular MRI. Stress imaging was performed
using a bolus of dipyridamole (0.84 mg/kg over 6 minutes). Delayed-enhanced MRI
study was used to assess the presence of myocardial necrosis.
Results: Eight women (48%) showed significant left ventricular fixed perfusion
defects (2 in one segment; 4 in two segments; 2 in three segments). The localization of the perfusion defects were anteroapical (n = 3), septal (n = 5) and inferior/
infero-lateral (n = 7). In all patients we found no transient myocardial perfusion
abnormalities in response to dypiridamole infusion or delayed enhancement
areas. In multivariable analysis, the factors independently linked to the presence
of fixed perfusion defects was hypertension (odds ratio = 3.5; 95% CI from 2.8 to
5.4; p 0.0001) and diabetes mellitus (odds ratio = 2.5; 95% CI from 1.8 to 4.3;
p 0.001).
Conclusion: In susceptible women such as those with typical angina, significant
areas of perfusion abnormalities may be visualized by MRI, indicating microcirculation damage despite normal angiogram.
B-349
11:42
Identification of residual ischemia in revascularized myocardial infarction
using 64-slice MDCT
M. Carlsson, A. Furtado, M. Saeed; San Francisco, CA/US
(marcus.carlsson@med.lu.se)
Purpose: To assess the potential of 64-slice MDCT in characterizing revascularized
infarcted myocardium at the cellular and microvascular levels.
Methods and Materials: Pigs (n=7) underwent 2 hr LAD occlusion/reperfusion. At
2-4 hrs and 1 week first-pass perfusion (FPP) (1 ml/kg of 300 mg/ml Omnipaque)
was performed using a dynamic cine (rotation time 60 s/bpm) sequence (mAS/
kV=100/120). Delayed contrast-enhanced images (DE) (mAS/kV=650/120) were
acquired every 2 min for 10 min to define infarcted myocardium and microvascular
impairment (representing microvascular obstruction and/or no- or low-reflow phenomenon). Max upslope, max attenuation and time to the peak were measured
from FPP plots. Hyperenhanced myocardium on DE was measured.
Results: In acute infarction, max upslope, maximum attenuation were significantly
reduced and time to the peak prolonged in infarcted myocardium (1.8p0.2 s-1,
51.8p2.6 HU, 21.9p3.1 s) compared to remote (7.3p1.4 s-1, 85.3p1.4 HU, 15.1p1.9 s)
(P = 0.03). Differential contrast between infarct (145p10 HU) and remote (99p4 HU)
myocardium was seen for 10 min on DE-MDCT, but only for 2-4 min between infarct
and LV blood pool (166p6 HU). DE-MDCT showed a core of hypoenhancement
(2.8p1.8% LV) surrounded by hyperenhancement at 2-4 hrs. Cine-MDCT showed
regional increase in anteroseptal wall thickness and lack of regional contractility at
2-4 hrs after reperfusion. At 1 week the hypoenhanced core was almost completely
resorbed (0.4p0.1% LV) and the infarction was partially resorbed (10.9p1.3% LV
compared to 15.7p1.2% LV at 2-4 hours). Furthermore, the wall swelling had subsided but showed remaining regional dysfunction.
Conclusion: 64-slice MDCT has the potential to identify residual ischemia on
FPP and monitor resorption of edema, microvascular impairment and infarction
on DE images.
B-350
11:51
Myocardial perfusion: Comparison of dual energy computed tomography
and magnetic resonance imaging, a pilot study
J. Ferda1, J. Baxa1, T. Flohr2, B. Schmidt2, B. Kreuzberg1; 1Plzen/CZ, 2Forchheim/DE
(ferda@fnplzen.cz)
Purpose: To compare the assessments of myocardial perfusion using ECG-gated
dual energy CT (DECT) and cardiac MRI (CMRI) including perfusion study and
late enhancement images.
Methods and Materials: The prospectively collected data were evaluated in 10
patients (mean age 72.1 years; 7 males, 3 females) with diabetic microangiopathy
(3x), myocardial infarction (4x) and normal findings (3x). Based on informed consent,
all patients underwent coronary DECT-angiography and CMRI. After intravenous
application of 80 ml of iomeprol (5 ml/s) DECT was executed on a dual-source
CT with the application of dual energy data acquisition. The system operated with
140 kV on tube A and with 100 kV on system B, both systems used collimation of 2
x (32 x 0.6 mm). DECT images were analyzed with the algorithm, which allowed to
obtain maps of the perfused blood volume in the myocardium. CMRI was performed
on a 1.5 T system, including a dynamic turboFLASH T1 sequence after application
of 7.5 ml of gadobutrol and an IR-FLASH T1 sequence delayed by 10 minutes.
The DECT perfusion blood volume images (DECT-PBV), peak intensity CMRI and
LE-MRI were compared.
Scientific Sessions
Results: Sufficient CT-angiograms of coronary arteries and DECT-BPV images
were obtained in all cases; misregistration artifacts of minor importance were noted
only in one case. There was good agreement between CT-BPV and peak-intensity
CMRI in all cases except one, where an artifact caused by beam hardening was
misinterpreted as perfusion deficit on DECT-BPV.
Conclusion: DECT exhibited a promising ability in the assessment of the involvement of the coronary arteries and its impact on myocardial perfusion within one
examination.
14:00 - 15:30
Room A
Musculoskeletal
SS 710
Shoulder/Upper extremity
Moderators:
R. Arkun; Izmir/TR
S. Waldt; Munich/DE
14:00
Magnetic resonance arthrography of the glenohumeral joint: Comparison
of T1-weighted two-dimensional sequences and volumetric interpolated
breathhold examination
H.M. Stockley, C. Hutchinson; Manchester/UK (hstockley@doctors.org.uk)
Purpose: To ascertain if there is any difference in the identification of anatomical
structures when comparing separately acquired T1-weighted (T1W), two-dimensional (2D) sequences and a volumetric interpolated breathhold examination
(VIBE) in magnetic resonance (MR) arthrography of the glenohumeral joint. Also, to
investigate if there is any difference between acquiring VIBE sequences in axial or
coronal planes. By incorporating VIBE sequences into MR arthrography protocols,
total scanning time could be reduced to approximately half its current value.
Methods and Materials: A total of 60 patients underwent 1.5-T MR imaging following injection of the glenohumeral joint with diluted gadolinium. The sequences
included T1W imaging with fat saturation in the axial, sagittal oblique and coronal
oblique planes and T1W VIBE imaging with water excitation in either the coronal
oblique or axial plane. Data were compared qualitatively for ease of identification
of anatomical structures and the presence of patient movement.
Results: Ligaments (P = 0.02), labrum (P = 0.09) and tendons (P = 0.006) were
more easily identified on separately acquired T1W 2D sequences compared to
VIBE sequences acquired in the axial plane, but differences were not statistically
significant when compared to VIBE images acquired in the coronal plane. Cartilage
(P 0.001) was more easily recognised on VIBE imaging during which there was
less patient movement (P 0.01) compared to T1W 2D imaging.
Conclusion: Differences found when comparing anatomical structures on separately acquired T1W 2D sequences with images generated using VIBE, acquired
in the axial plane, are shown to be statistically significant.
B-352
14:09
Glenoid labrum and articular cartilage lesions of the glenohumeral joint:
Diagnostic effectiveness of 3D water-excitation true FISP MR arthrography
T.J. Dietrich1, M. Zanetti2, N. Saupe2, C.W.A. Pfirrmann2, S.F. Fucentese2,
J. Hodler2; 1Münsterlingen/CH, 2Zurich/CH (tdiet@gmx.net)
Purpose: To evaluate the diagnostic effectiveness of MR arthrography using a
transverse 3D water-excitation true fast imaging with steady-state precession
(FISP) MR arthrography in the detection of labrum and cartilage abnormalities of
the glenohumeral joint.
Methods and Materials: Seventy-five shoulders were included in this retrospective
study. Imaging parameters were: transverse plane; repetition time [msec]/echo time
[msec], 9.24/3.17; flip angle, 28°; field of view, 180 x 158 mm; matrix, 512 x 256;
section thickness, 1.7 mm. MR-Imaging reading was performed blinded to clinical
information and the arthroscopy report. The anterior and posterior labrum as well
as the humeral and glenoidal cartilage were assessed separately. A classification
system of three grades was used: normal cartilage, superficial and deep cartilage
lesions as well as normal labrum, labral degeneration and labral tear. Arthroscopy
served as the reference standard.
Results: For the detection of superficial and deep cartilage lesions sensitivity,
specificity and accuracy varied between 60 and 93%, 76 and 89%, 76 and 89%.
For deep cartilage lesions sensitivity, specificity and accuracy varied between 86
and 100%, 89 and 97%, 90 and 96%. For the diagnosis of labral degeneration
and tears sensitivity, specificity and accuracy varied between 25 and 94%, 74 and
B-353
14:18
Is a single MR arthrography series in ABER position as accurate in
detecting labroligamentous lesions as conventional MR arthography?
S.A. Schreinemachers, V.P.M. van der Hulst, W. Willems, S. Bipat,
H.-J. van der Woude; Amsterdam/NL (s.a.schreinemachers@olvg.nl)
Purpose: To retrospectively compare accuracy of single MR arthrography series
in abduction external rotation (ABER) with conventional MR arthrography for the
detection and characterization of anteroinferior labroligamentous lesions, with
arthroscopy as reference standard. Interobserver variability of both protocols was
determined.
Methods and Materials: Institutional review board approval was obtained; informed
consent was waived. MR arthrograms, including oblique axial fat suppressed T1weighted images in ABER position and conventional imaging directions (SET) of
250 patients (170 men, 80 women; mean age, 36 years), were retrospectively and
independently evaluated by three reviewers. Reviewers were blinded to clinical
information and arthroscopic results. Labroligamentous lesions were registered in
both ABER and SET. The lesions were subclassified (Bankart, Perthes, ALPSA or
lesions not otherwise specified). Interobserver agreement was assessed by Kappa
statistics for all 250 patients. 92 of 250 patients underwent arthroscopy. Sensitivity, specificity and accuracy of ABER versus SET were calculated and compared
using paired McNemar test.
Results: Kappa-values of the ABER and SET ranged from 0.44-0.56 to 0.44-0.62,
respectively. According to arthroscopy 45 of 92 patients had an intact anteroinferior
labrum and in 44 patients a labroligamentous lesion (eight Bankart, seven Perthes,
29 ALPSA and three lesions not otherwise specified) was diagnosed. There were
no statistically significant differences between ABER and SET regarding sensitivity
(83-89% and 88-95%, respectively), specificity (82-95% and 84-91%) and overall
accuracy (52- 63% and 55-69%).
Conclusion: The results of a single MR arthrography series in ABER position are
comparable with those of conventional MR arthrography for detecting labroligamentous lesions.
B-354
14:27
Inter- and intraobserver variability of MR arthrography in the detection and
classification of superior labral anterior posterior lesions: Evaluation in 75
arthroscopically confirmed cases
K. Holzapfel, S. Waldt, J. Paul, M. Bruegel, E.J. Rummeny, K. Wörtler; Munich/DE
(holzapfel@roe.med.tum.de)
Purpose: To determine the inter- and intraobserver variability of MR arthrography
(MR-A) of the shoulder in the detection and classification of superior labral anterior
posterior (SLAP) lesions.
Methods and Materials: MR arthrograms of 75 patients who underwent MR-A
prior to arthroscopy were retrospectively analyzed by two blinded readers for the
presence and type of SLAP lesions. MR arthrograms were reviewed twice by each
reader with a time interval of 4 months between both readings. Sensitivity and
specificity for diagnosing SLAP lesions and accuracy for lesion classification were
determined for each reader. Inter- and intraobserver agreement for detection and
classification of SLAP lesions were calculated using + coefficients.
Results: Arthroscopy confirmed 40 SLAP lesions: type I (n = 1), type II (n = 32),
type III (n = 4), type IV (n = 3). Compared with arthroscopy, sensitivity, specificity,
and accuracy for detecting SLAP lesions by MR-A were 92.5, 82.6 and 88.9%
(Reader1) and 92.5, 87.0 and 90.5% (Reader2). MR arthrographic and arthroscopic
grading were concurrent in 82.5 and 85.0% of cases. Diagnosis of SLAP lesions was
concurrent between both readers in 98.5% and classification of lesions in 95%. Interobserver agreement was almost perfect (+ = 0.90) for the detection and substantial
(+ = 0.78) for the classification of SLAP lesions. Intraobserver agreement of both
readers was almost perfect for the detection of SLAP lesions (+ = 0.96, + = 0.93).
For the classification of SLAP lesions, intraobserver agreement was substantial (+
= 0.79) in one and almost perfect (+ = 0.92) in the other reader.
Conclusion: MR-A allows reliable and accurate detection and classification of
SLAP lesions with high inter- and intraobserver agreement.
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84%, 64 to 86%. For labral tears the corresponding values varied between 33 and
100%, 87 and 89%, 86 and 88%.
Conclusion: The diagnostic effectiveness of MR arthrography using a transverse
3D true FISP sequence is useful in the detection of lesions of the labrum and of
the thin glenohumeral cartilage.
Scientific Sessions
B-355
14:36
Magnetic resonance shoulder arthrography: Posterior approach under
ultrasonographic guidance and abduction
E. Faiella, F. Martina, L. Stellato, F. Carcione, P. Sedati, F. Grasso,
B. Beomonte Zobel; Rome/IT (e.faiella@unicampus.it)
Purpose: To describe the technique performed under ultrasonographic guidance
and to assess its efficacy.
Methods and Materials: 38 consecutive patients were enrolled in the study, after
obtaining informed consent. All the procedures were performed with the left arm
(15) or the right arm (23) in abduction, with the corresponding hand over the controlateral scapulae in order to obtain a distension of the posterior capsula. Sterile
technique was used and a 22-gauge needle was used. Under ultrasonographic
control, the tip of needle was followed until its proper position within the articular
cavity and the contrast media was injected. The procedure was performed by an
interventional radiologist and one resident in training in interventional radiology;
we considered technical results, number of attempts, experienced pain, time of
procedure and complication.
Results: The procedure was performed in all the cases. The mean time of the
procedure was 7.2 p 1.4 min. The pain, on a scale from 0 to 10, was reported as
3.2. One attempt was performed in 31 patients (81%), two in the remaining 7 (18%).
No complications were observed.
Conclusion: MR shoulder arthrography performed with posterior approach under
ultrasonographic guidance and abduction (PAUGA) is a safe, fast and well tolerated
technique that can be performed with optimal results with no need of X-ray.
B-356
14:45
MR imaging of the intraarticular disc of the acromioclavicular joint at 3.0 T
A. Foteinos1, C. Petchprapa2, J. Bencardino2, M. Schweitzer3; 1Peiraeus/GR,
2
New York, NY/US, 3Ottawa, ON/CA (foteinosa@hotmail.com)
Purpose: To study the MR appearance of the acromioclavicular joint disc at 3.0 T.
Methods and Materials: Review of axial PDw images of the shoulder MRI of 48
patients (23 male, 25 female, mean age: 50.9) was performed by two radiologists.
The acromioclavicular joint disc was assessed with regard to its presence, signal
and morphology, and osteoarthritic (OA) joint changes were also assessed. Statistical analysis estimated reader agreement, possible subject age influence on the
likelihood of disc detection and correlations of: (1) subject age with OA changes,
disc presence, morphology and signal, and (2) OA changes with disc presence,
morphology and signal.
Results: A disc was detected by both readers for 36/48 (75%) subjects and kappa
coefficient was 0.67, which indicates good agreement. Kappa values were 0.29 for
disc presence, 0.21 for morphology, and 0.26 for signal, which indicate fair agreement. Kappa value for OA changes was 0.42, which indicates moderate agreement.
There was no significant correlation of subject age with disc presence or signal,
but there was a significant positive correlation (P b 0.015) of subject age with disc
morphology. There was no significant correlation of OA changes with disc presence or signal, but there was a significant positive correlation of OA changes with
disc morphology (Pb0.0064). The significant correlation of OA changes with disc
morphology is not a consequence of a mutual dependence on age and gender.
Conclusion: Detailed evaluation of the acromioclavicular joint disc is limited even
at 3.0 T. However, disc morphology seems to be strongly correlated with OA joint
changes.
B-357
14:54
MDCT arthrography is accurate for detecting and grading SLAP retears in
athletes with prior shoulder surgery
M. De Filippo1, M. Onniboni1, R. Averna1, P. Araoz2, F. Pogliacomi1, N. Sverzellati1,
M. Zompatori1; 1Parma/IT, 2Rochester, MN/US (massimo.defilippo@unipr.it)
Purpose: To evaluate the sensitivity and specificity of MDCT arthrography to detect
retears of superior labral anterior to posterior (SLAP) lesions of the shoulder in
athletes with previous shoulder surgery and with clinical suspicion of relapse.
Methods and Materials: Multidetector CT (MDCT) arthrograms performed in
45 shoulders in 45 professional athletes (35 males, 10 females, mean age 29
years, range 21-38 years) who had arthroscopy within 30 days of the MDCT were
retrospectively reviewed. MDCT arthrography was performed after intra-articular
injection of contrast material and volumetric acquisition on a 16-detector CT
scanner. All examinations were independently reviewed by two experienced musculoskeletal radiologists and disagreements were resolved by a third experienced
musculoskeletal radiologist. The sensitivity and specificity of MDCT arthrography
for detecting any Snyder type II-IV tear was evaluated, using arthroscopy as the
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reference standard. The number and percentage of tears in which MDCT arthrography allowed correct Snyder type classification were reported. The interobserver
variability of MDCT arthrography for correct Snyder classification was reported
using the kappa statistic.
Results: Using MDCT arthrography SLAP retears were correctly identified in 35
of 37 patients (sensitivity = 95%) and the absence of SLAP retears identified in 7
of 8 patients (specificity = 88%). MDCT arthrography and arthroscopy grades were
concurrent in 30 of 37 of patients with SLAP re-tears (81%). MDCT arthrography
interobserver variability was substantial (kappa = 0.76).
Conclusion: MDCT arthrography is a useful technique for evaluating SLAP retears
and may be an alternative to MRI.
B-358
15:03
Virtual glenoidplasty: CT-based patient-specific modeling of glenoid rim
defects
G. Diederichs1, H. Seim1, H. Meyer1, A.S. Issever1, T.M. Link2, R.J. Schröder1,
M. Scheibel1; 1Berlin/DE, 2San Francisco, CA/US (gerd.diederichs@charite.de)
Purpose: The reconstruction of glenoid bone defects after chronic shoulder instability requires accurate preoperative planning. A method is presented to quantify the
defect size and generate a 3D model of the optimal bone graft for augmentation
by matching the fractured glenoid with the contralateral side.
Methods and Materials: Ten paired shoulders from five body donors (subjects: 3
women, 2 men; mean 85 years) and 60 paired shoulders in 30 patients (controls: 9
women, 21 men; mean 21 years) were examined with CT to determine the bilateral
comparability by assessment of the maximum glenoid diameters, surface area and
volume. After creation of a glenoid rim defect in the study group, repeated CT scans
were superimposed with the data from the contralateral side. The defect size was
quantified and the missing fragment virtually reconstructed. Accuracy was evaluated
by comparing the virtually repaired glenoid with the predefect scan.
Results: There were no significant side-to-side differences in the intact shoulders
(P 0.05). After creation of the glenoid defects, there was a mean decrease of
31% in the anteroposterior diameter, 34% in the surface area and 19% in volume.
The virtually reconstructed glenoids did not differ significantly from the predefect
scans. The average predefect-to-postdefect difference was 3% for the anteroposterior diameter (R2 0.71), 6% for the surface area (R2 0.82) and 4% for the volume
(R2 0.98).
Conclusion: A precise 3D model of the glenoid bony defect can be generated.
The computer simulation provides a virtual model of the bone graft, which may
potentially improve arthroscopic bone augmentation.
B-359
15:12
Value of real-time sonoelastography in lateral epicondylitis: Comparison of
findings between patients and healthy volunteers
T. De Zordo, R. Faschingbauer, S. Lill, C. Fink, W. Jaschke, A. Klauser;
Innsbruck/AT (Tobias.De-Zordo@i-med.ac.at)
Purpose: To evaluate the value of sonoelastography (EUS) in assessing common
extensor tendon origins in healthy volunteers and patients complaining of symptoms of lateral epicondylitis. The findings were compared to clinical examination,
ultrasound (US) and power Doppler ultrasound (PDUS).
Methods and Materials: A total of 38 elbows of 32 consecutive patients (10 men,
22 women) complaining of lateral epicondylitis (6 bilateral) and 44 asymptomatic
elbows of 28 healthy volunteers (16 bilateral; 11 men, 17 women) were assessed
by using US and EUS. Clinical examination was performed and pain was classified
by a visual analogue scale.
Results: In healthy volunteers, EUS images showed hard tendon structure in
96.21% and in 3.79% mild alterations were found. Using EUS in patients, 33.33%
of tendon thirds showed hard structure but softening of different grades was found
in 66.67%, which was significantly different from healthy volunteers (P 0.001).
Lateral collateral ligament involvement (10/8) and involvement of the overlaying
fascia (11/5) were more commonly detected by EUS. Sensitivity was 100%, specificity 89%, and accuracy 94% with clinical examination as reference standard. Good
correlation to US findings was found (R r 0.900). No correlation between US or
EUS and PDUS imaging could be detected, but PDUS imaging shows a strong
correlation with VAS score.
Conclusion: EUS was valuable in the detection of intratendinous and peritendinous alterations of the lateral epicondylitis and enabled differentiation between
healthy and symptomatic extensor tendon origins with an excellent sensitivity. An
excellent correlation to US was found and EUS was more sensitive in detecting
lateral epicondylitis.
Scientific Sessions
B-360
15:21
Gamekeeper’s thumb: A new US dynamic maneuver to detect the Stener
lesion
B. Bordet, O. Fantino, J. Borne; Lyon/FR (bertrandbordet@voila.fr)
14:00 - 15:30
Room B
Abdominal Viscera (Solid Organs)
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Pancreas
Moderators:
M.A. Bali; Brussels/BE
G. Morana; Treviso/IT
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Feasibility of pancreatic perfusion imaging with 320-slice dynamic CT
S. Kandel, H. Meyer, C. Kloeters, V. Romano, P. Hein, P. Rogalla; Berlin/DE
(sonja.kandel@charite.de)
Purpose: To establish and evaluate a scanning protocol of the pancreas using
320-slice dynamic volume CT in patients with primary pancreatic cancer.
Methods and Materials: 20 patients with clinically known or strongly suspected
primary pancreatic cancer were scanned. The dynamic CT protocol consisted of
20 intermittent low-dose scans that were applied within 2 minutes. The following
scan parameters were used: 100 kV tube voltage, 40 mAs tube current, 0.5 s gantry
revolution time, 16 cm collimation, 0.5 mm slice thickness. After intravenous contrast
media injection of 60 ml at 10 ml/s and dynamic density measurements in the right
ventricle, dynamic scanning was initiated manually. Perfusion was determined with
the gradient-relationship technique, time-density-curves and coloured perfusion
maps were created. Pancreatic tumour perfusion [1/min] was compared to the
perfusion measured in normal pancreatic tissue. Statistic analysis was performed
using the Wilcoxon test for paired samples.
Results: In all scans, the entire pancreas was completely covered by the 16 cm
scanning region. The perfusion values of normal pancreatic tissue ranged from 1.07
to 1.26 min-1, in pancreatic tumours perfusion ranged between 0.17 to 0.59 min-1.
Perfusion of pancreatic tumour was significantly lower than in normal pancreatic
tissue (p 0.007) in all 20 patients. Total radiation exposure was comparable to
the dose deposited by standard tri-phasic pancreas CT scans.
Conclusion: Perfusion imaging of the pancreas carries the potential to improve an
early characterization of pancreatic disease and may serve as a clinically valuable
tool for monitoring therapy response in patients with pancreatic malignancy.
B-362
14:09
Preoperative multislice computed tomography for evaluation and the
assessment of resection criteria of patients with pancreatic diseases
C. Grieser, L. Grajewski, I. Steffen, B. Hamm, J. Langrehr, E. Lopez Hänninen,
T. Denecke; Berlin/DE (christian.grieser@charite.de)
Purpose: To evaluate the accuracy of multislice computed tomography (MSCT)
for preoperative evaluation and the assessment of resection criteria in patients
with pancreatic diseases who underwent subsequent exploratory laparoscopy or
pancreatic resection.
Methods and Materials: A total of 105 patients (age, 21 to 84 years; mean, 57 p 11)
who underwent exploratory laparoscopy or pancreatic resection at our institution
B-363
14:18
Value of MR diffusion-weighted imaging in differentiating pancreatic
carcinoma from chronic mass-forming type pancreatitis on 3 T MR unit
B. Song, J. Chen, B. Wu; Chengdu/CN (cjr.songbin@vip.163.com)
Purpose: To investigate the value of MR diffusion-weighted imaging (DWI) in
differentiating pancreatic carcinoma from chronic mass-forming type pancreatitis
on 3 T MR system.
Methods and Materials: Twenty patients with 13 pancreatic carcinoma and 7
chronic mass-forming type pancreatitis proven by surgical pathology, as well as
14 healthy volunteers, were studied using routine pancreas MR protocol and DWI
on a 3 T MR system. The SE-EPI sequence and ASSET technique were used for
DWI and b value was selected at 400, 600, 800 and 1000 s/mm2, respectively. The
corresponding apparent diffusion coefficient (ADC) values were measured and
statistically analyzed.
Results: 1. DWI of the healthy volunteers showed intermediate signals of pancreas.
2. DWI of pancreatic tumor masses showed homogenous high signal intensity
relative to the surrounding pancreatic tissue with clear boundary. Under different
b values, the tumor ADC values were (1.63p0.235), (1.42p0.126), (1.36p0.170)
and (1.26p0.178)×10-3 mm2/s, respectively, which were significantly lower than
those of non-tumor region: (2.11p0.444)×10-3 mm2/s, (1.83p0.230)×10-3 mm2/s,
(1.81p0.426)×10-3 mm2/s, (1.60p0.230)×10-3 mm2/s, and of the normal pancreas:
(1.85p0.350)×10-3 mm2/s, (1.69p0.290)×10-3 mm2/s, (1.67p0.268)×10-3 mm2/s,
(1.42p0.221)×10-3 mm2/s. DWI of chronic pancreatitis showed inhomogeneous
slightly hyper-intense signal with blurring borders. Under different b values, the
ADC values of the inflammatory masses of pancreatitis were (1.69p0.150),
(1.56p0.199), (1.59p0.172) and (1.35p0.080)×10-3 mm2/s, respectively, which
were higher than those of pancreatic carcinoma. When b was set to 800 s/mm2,
the difference in ADC values between carcinoma and pancreatitis was statistically
significant (P 0.05).
Conclusion: MR DWI technique can be very useful in differentiating pancreatic
carcinoma from chronic mass-forming type pancreatitis.
B-364
14:27
Pancreatic ductal adenocarcinoma versus focal chronic pancreatitis:
Qualitative and quantitative evaluation by using diffusion-weighted MRI
with parallel imaging technique and multiple b gradient factor values
P. Boraschi, F. Donati, C. Bertucci, S. Salemi, R. Gigoni, M. Cossu, C. Bartolozzi,
F. Falaschi; Pisa/IT (p.boraschi@do.med.unipi.it)
Purpose: To determine the usefulness of qualitative and quantitative evaluation by
using diffusion-weighted MR imaging (DW-MRI) with parallel imaging technique and
multiple b gradient factor values in the differential diagnosis between pancreatic
ductal adenocarcinoma (PDA) and focal chronic pancreatitis (FCP).
Methods and Materials: Twelve patients with PDA and eight cases of FCP (1/8
autoimmune pancreatitis) underwent MR imaging at 1.5 T. After the acquisition
of axial T1/T2w sequences and coronal MRCP, DW-MRI was performed using
axial breath-hold single-shot spin-echo echo-planar (SE-EPI) sequence (parallel
imaging factor, 3); the values of b factor were set at 0, 300, 500, 700 and 1,000 s/
mm². All DW images were blindly interpreted. Qualitative evaluation was performed
by consensus reading of two reviewers who graded the presence of lesions on a
three-point scale on the basis of their signal intensity on high b value as follows:
0 (no signal); 1 (mild/moderate signal); 2 (strong signal). Quantitative evaluation
was performed by two other radiologists in conference, who calculated mean ADC
values for each lesion using a b-value of 500 s/mm².
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Purpose: Thumb metacarpophalangeal joint (MCP) strain is a frequent lesion.
When the ulnar collateral ligament (UCL) is torn, the adductor aponeurosis can
be jammed under the ligament stump; known as the Stener lesion, this compromises effective healing and requires surgical treatment. We here propose a new
dynamic maneuver, flexing-extending the inter-phalangeal joint so as to visualize
the UCL and the sliding of the adductor aponeurosis expansion, thus detecting
the Stener lesion.
Methods and Materials: A prospective study on 56 patients assessed ultrasound
(US) detection of the Stener lesion using this maneuver, against surgical data as
gold standard.
Results: US showed 100% sensitivity in detecting torn ligament (32 patients). All
patients with Stener lesions on US underwent surgery, with 95.4% sensitivity and
80% specificity.
Conclusion: Thus, US with this new specific maneuver provides reliable and
reproducible detection of the Stener lesion. Saving videos allows the medical or
surgical correspondent to better understand the US examination.
between 2001 and 2006 because of pancreatitis or pancreatic tumour and had preoperative abdominal MSCT (4-to 64-slice-scanners, triphasic contrast protocol) were
enrolled retrospectively. MSCT data and multiplanar reformatted images (MPR) were
reviewed by two independent blinded observers. Diagnostic criteria were dignity,
extrapancreatic tumor expansion, vessel infiltration, pathologic lymphnodes, liver
metastasis and the resectability (criteria: M0, no arterial infiltration). Preoperative
imaging findings were correlated with intraoperative results.
Results: Among all 105 patients, 70 pancreatic tumors and 35 benigne pancreatic
diseases were found (accuracy of 98%; ROC analysis, AUC of 0.97). Accuracy for
extrapancreatic tumoral expanson for observer 1 (O1) and 2 (O2) was 93% (with
MPR, 97%; kappa=1.0), for vessel invasion accuracy was both 99% (100%) for
the coliac trunc, 94/95% (100/99%) for the superior mesentery artery, 95/97%
(99/100%) for the common hepatic artery, both 98% (both 99%) for the splenic
artery (kappa=0.79-1.0). The accuracy of a possible resectability was 90% for O1
(91%) and 88% (90%) for O2 (kappa=0.97).
Conclusion: MSCT in combination with MPR is a highly accurate method for the
evaluation and the assessment of resection criteria in patients with pancreatic
diseases.
Scientific Sessions
Results: The reviewers graded as “2” all PDA and autoimmune pancreatitis (false
positive), whereas the other lesions showed “no signal” on high b value DWI, with
sensitivity and specificity of 92 and 100% for the detection of pancreatic malignancy.
Mean ADC values were 1.43 p 0.0033 mm²/s for PDA and 2.09 p 0.013 mm²/s for
FCP (P 0.05).
Conclusion: Qualitative and quantitative evaluation by using DW-MRI might be
helpful in the differential diagnosis between PDA and FCP. DW-MRI can be easily
performed as an adjunct to conventional MR study of the pancreas.
B-365
14:36
Diffusion-weighted magnetic resonance imaging (DWI) for monitoring of
advanced pancreatic adenocarcinoma under chemotherapy
C. Losio, M. Orsi, F. De Cobelli, M. Reni, S. Cereda, A. Del Maschio; Milan/IT
(losio.claudio@hsr.it)
Purpose: In advanced pancreatic adenocarcinoma, chemotherapy is essential to
relieve symptoms, improving quality of life; however, eventual tumor response is
measurable only 2-3 months after treatment. Sensitive to modifications of water
diffusivity, DWI is a potential tool to monitor intralesional early changes induced
by chemotherapy. Our aim was to test the feasibility and usefulness of pancreatic
DWI in this setting.
Methods and Materials: 11 patients with advanced pancreatic adenocarcinoma
(stage III and IV) underwent MRI with addition of diffusion-weighted-EPI sequences
(b=600), before and during a 4-drugs-gemcitabine-based chemotherapeutic treatment (MRI repeated 2 weeks after each cycle for 2 months). Tumor mean areas
and apparent diffusion coefficient (ADC) values were assessed and compared
during follow-up, by tracing perilesional ROIs on morphologic images and ADC
maps. Response was quantified with CT, PET-CT (RECIST criteria) and serum
CA19-9 at 2-3 months.
Results: DWI was successfully performed in all patients; during chemotherapy,
mean lesional ADC showed a statistically significant increase (1.85p0.26 vs
1.52p0.24 mm2/s; P=0.001) compared to baseline 2 weeks after second chemotherapeutic cycle (1 month of treatment), probably due to drug-induced citolysis,
while a decrease in size was observable only after fourth cycle (2 months). In
non-responder patients, no modifications of ADC were recorded.
Conclusion: In pancreatic carcinoma DWI, providing accurate measurements of
ADC is sensitive to modifications induced by chemotherapy. During chemotherapy,
an increase of ADC values precedes tumor regression; furthermore, this seems to
occur only in responder patients, suggesting a possible role of ADC as predictive
marker of early response to chemotherapeutic treatment.
B-366
14:45
Contrast-enhanced ultrasound of pancreatic lesions: PAMUS (pancreatic
multicenter ultrasound study) preliminary results
M. D’Onofrio, F. Principe, R. Malagò, R. Pozzi Mucelli; Verona/IT
(mirko.donofrio@univr.it)
Purpose: To evaluate the possibilities of contrast-enhanced ultrasound (CEUS) in
the characterization of pancreatic lesions (solid and cystic) detected at ultrasound
(US), referring to pathology as the gold standard.
Methods and Materials: From radio-pathologic archives, 809 pancreatic lesions
studied with CEUS from 2002 to 2007 were retrospectively considered and reviewed.
The lesions had to be pathologically proven to be included in the study.
Results: Solid lesions were: 516 ductal adenocarcinomas, 142 endocrine tumors,
18 mass-forming pancreatitis, 11 pseudopapillary tumors, 8 anaplastic carcinomas,
9 metastases, 5 lymphomas and 4 rare tumors (2 leiomiosarcomas, 1 liposarcoma,
1 pancreatoblastoma). Cystic lesions were: 35 mucinous cystoadenomas, 19 serous cystoadenomas, 32 IPMN, 6 pseudocysts, 4 cystoadenocarcinomas. Among
the solid lesions, 421/516 (81.6%) adenocarcinomas, 108/142 (76%) endocrine
tumors, 13/18 (72.2%) pancreatitis, 7/11 (63.6%) pseudopapillary tumors, 7/8
(87.5%) anaplastic carcinomas, 5/9 (55.5%) metastasis and 3/5 (60%) lymphomas
were correctly characterized. Among the cystic lesions, 32/35 (91.4%) mucinous
cystoadenomas, 12/19 (63.2%) serous cystoadenomas, 27/32 (84.4%) IPMN,
5/6 (83.3%) pseudocystis and 4/4 (100%) cystoadenocarcinomas were correctly
characterized. For solid lesions the CEUS sensitivity, specificity, VPP and VPN,
accuracy was respectively 73.8, 91.2, 84.2 and 91.1%; 90.5%. While for cystic
lesion sensitivity, specificity, VPP and VPN, accuracy of CEUS was respectively
83.3, 99.2, 70.8 and 99.2%; 98.9 %.
Conclusion: CEUS can characterize solid and cystic lesions according to pathology with an accuracy of 90.5 and 98.9 %, respectively.
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B-367
14:54
Pancreatic involvement in patients with hereditary hemorrhagic
telangiectasia
J.-P. Pelage, A. Lacout, G. Lesur, J. Roume, A. Beauchet, P. Lacombe;
Boulogne/FR (jean-pierre.pelage@apr.aphp.fr)
Purpose: To prospectively evaluate the pancreatic involvement in patients with
hereditary hemorrhagic telangiectasia (HHT). To report the types of pancreatic
abnormalities identified in HHT patients.
Methods and Materials: All consecutive patients diagnosed with HHT underwent
contrast-enhanced 16-slice multidector row computed tomography (MDCT). The
pancreas was carefully evaluated with special emphasis on telangiectases and
arteriovenous malformations (AVMs). The size and location of identified telangiectases was recorded. The diameter of the splenic artery was measured and the
presence of aneurysms was recorded.
Results: Thirty-five patients (19 women and 16 men, mean age 48.4 years) have
been enrolled. MDCT detected pancreatic vascular abnormalities in 11 patients
(31%). Nine patients had telangiectases and 2 had AVMs. A total of 23 telangiectases and 7 AVMs were identified. Most of the 23 identified telangiectases were
located in the cephalic or caudal portions of the pancreas. The mean diameter of
telangiectases and AVMs was 4.1 p 1.3 mm and 5.7 p 1.2 mm. In addition, 7 patients
(19%) had a sacciform aneurysm of a branch of the splenic artery (mean diameter
8.7 p 3.1 mm) including 4 patients with telangiectases/AVMs. No correlation was
found between the presence of pancreatic telangiectases/AVMs and liver and/or
lung involvement. There was a trend towards enlarged splenic artery in patients
with pancreatic telangiectases/AVMs.
Conclusion: Pancreatic telangiectases were considered as a rare finding in patients with HHT. With the use of MDCT, pancreatic abnormalities can be identified
in one-third of HHT patients.
B-368
15:03
Resectable pancreatic adenocarcinoma: Enhancement pattern at
transabdominal contrast-enhanced ultrasonography as preoperative
prognostic factor
M. D’Onofrio, F. Principe, R. Malagò, G. Zamboni, R. Pozzi Mucelli; Verona/IT
(mirko.donofrio@univr.it)
Purpose: Tumoral perfusion is a functional features of pancreatic adenocarcinoma
resulting from neoangiogenesis. The aim of our study was to determine whether
enhancement pattern of pancreatic adenocarcinoma at contrast-enhanced ultrasonography (CEUS) is related to patients prognosis after surgery.
Methods and Materials: CEUS of 42 resected adenocarcinomas were retrospectively reviewed. Enhancement at CEUS was scored as: group A=poorly vascularized
(presence of avascular areas) or group B=well vascularized (absence of avascular
areas). All the lesions were resected and underwent pathological examination assessing tumor differentiation as: undifferentiated (poorly differentiated) or differentiated (moderately and well differentiated) and mean vascular density value (MVD).
The results of CEUS enhancement and pathology were correlated (Spearman’s
test). Survival analysis was made (Kaplan-Meier method).
Results: There were 30 differentiated and 12 undifferentiated adenocarcinoma
at pathology. At CEUS 10 lesions were poorly vascularized, while 32 lesions
were well vascularized. Good correlation was found between CEUS groups and
tumoral differentiation (rs=0.51; p=0.001). Positive strong correlation was observed
between CEUS and MVD (rs=0.74; p 0.0001). Median survival in patients with
group A vascularization at CEUS was significantly lower than patients with group B
(p=0.015). Cox proportional hazard model revealed as predictor of higher mortality
the presence of tumor poorly vascularized at CEUS (p=0.0001).
Conclusion: CEUS enables accurate depiction the vascularization of adenocarcinoma with a strong correlation to pathology and MVD. The enhancement of
adenocarcinoma at CEUS appears to be a valid preoperative prognostic factor.
B-369
15:12
US-guided fine-needle aspiration cytology of 545 focal pancreatic lesions:
Accuracy and short-term complications
G.A. Zamboni, M. D’Onofrio, A. Idili, R. Iozzia, E. Manfrin, R. Pozzi Mucelli;
Verona/IT (gzamboni@hotmail.com)
Purpose: To assess the accuracy and short-term complication rate of US-guided
fine-needle aspiration cytology (FNAc) of focal pancreatic lesions.
Methods and Materials: We reviewed 545 consecutive US-guided FNAc of focal
pancreatic lesions performed between January 2004 and June 2008. FNAc was
performed using 20G or 21G needles. The pathologist onsite evaluated material
appropriateness and provided the diagnosis. We reviewed the final diagnosis and
Scientific Sessions
the radiological and medical records of all patients to assess for onset of complications during the procedure or in the short term (b7 days).
Results: The study population included 262 females and 283 males. Mean patient age was 62 years (range 25-86). Of all the lesions, 63% were in the head/
uncinate process, 35.2% in the body/tail and for 10 lesions (1.8%) the site was not
specified. Sampling was diagnostic in 508/545 (93.2%) cases. Excluding the 37
non-diagnostic samplings, US-guided FNAc had 100% sensitivity, 90.6% specificity,
99.4% positive predictive value and 100% negative predictive value. Final diagnosis
was adenocarcinoma in 76.8% patients, endocrine tumor in 3.8%, pancreatitis in
2.4%, metastasis in 0.9%, lymphoma in 0.7%. Of the 545 procedures, 539 (98.9%)
were uneventful. In two patients, post-procedure abdominal fluid, not present before
the procedure, was noted. Four patients had onset of post-procedure pain, without
any finding on subsequent imaging. No major complication occurred.
Conclusion: US-guided cytology is a safe and accurate procedure for the correct
clinical and therapeutic definition of focal pancreatic lesions. The presence on site
of a cytologist allows for a high rate of diagnostic procedures, reducing the need
for patient recall.
15:21
Vascular complications after pancreatic transplant: Evaluation with MDCT
V. Battaglia, C. Cappelli, S. Mazzeo, G. Caproni, L. Novaria, C. Bartolozzi; Pisa/IT
(novetrequarti@yahoo.it)
Purpose: To analyse the role of MDCT in evaluating suspected vascular complications and related parenchymal alterations in patients with transplanted pancreas.
Methods and Materials: 86 patients who submitted to pancreatic transplantation
(bladder or enteric exocrine drainage) underwent MDCT because of suspected
vascular complications, within 1 week - 15 months after transplant. Post-contrastographic study was performed in pancreatic and venous phases. Native and 2D-3D
reconstructed images were analysed in order to identify: 1) the presence of vascular
complications, 2) glands morphology, and 3) parenchymal enhancement. Gold
standards were histological examination after graft removal/laparoscopic biopsy
and clinical/MDCT follow-up.
Results: 52 patients showed no vascular abnormalities; in all cases, glands
dimensions and parenchymal densities ranged between normal values. In 34
patients, MDCT depicted 26 thrombosis (7 arterial, 10 venous, 9 artero-venous);
4 chronic arterial graft stenoses; 2 arterial graft ectasia; 1 arterial graft inflammation; 1 artero-venous fistula. In all artero-venous thromboses and in 6 venous
thromboses, parenchyma did not enhance and grafts were explanted. In 4 venous
thromboses (increased pancreatic dimensions/decreased enhancements) and in 2
cases of acute arterial thromboses (normal parenchyma), patients underwent successfully heparinic and fibrinolytic therapies, respectively. In 2 arterial thromboses
with collateral circula (normal parenchyma) and in 5 chronic arterial thromboses/
stenoses (smaller and calcified parenhyma), no therapy was performed. In all other
cases of vessels complications (normal parenchyma), surgical/medical therapies
were anyway applied.
Conclusion: MDCT has revealed useful in evaluating graft vessels, morphology and
parenchymal enhancement. Particularly, in cases of suspected vascular complications, MDCT can help in suggesting the best therapeutic approach.
14:00 - 15:30
Room F1
Interventional Radiology
SS 709a
Embolisations and biopsies
Moderators:
M. Given; Dublin/IE
T. Roeren; Aarau/CH
B-371
14:00
Live 3D-fluoroscopy guidance during needle interventions: Clinical
implications and benefits
S.J. Braak, M.J. van Strijen, M. van Leersum, H.W. van Es, J.P.M. van Heesewijk;
Nieuwegein/NL (sjbraak@gmail.com)
Purpose: Demonstrating clinical implication and benefits of live 3D-fluoroscopy
guidance for needle interventions.
Methods and Materials: This new technology uses a flat panel detector system
rotating 180°-240° around the patient producing a cone-beam soft tissue CT. Within
this 3D-data set, the target lesion and needle entrance are defined avoiding essential structures. After co-registering the 3D-data with the fluoroscopy, the calculated
B-372
14:09
Treatment of vascular injury in spinal trauma
H. Sahin, O. Sahin, I. Oran, S. Cagli, M. Zileli; Izmir/TR (hilalcimen@gmail.com)
Purpose: Vascular complications during spinal trauma are fortunately few in number.
We retrospectively reviewed vascular injuries encountered after spinal trauma that
were diagnosed during the last 5 years in our institution.
Methods and Materials: The authors reviewed 15 patients with a mean age of 47
years (5-65 years) having spinal trauma with associated vascular injuries diagnosed
by means of catheter angiography. All patients were suspicious for vascular injury
after an initial radiological and clinical work-up.
Results: Three patients were asymptomatic, while the remaining 12 had symptoms
related to vascular injury (6 had neurologic symptoms and the remaining 6 had
symptoms unrelated to the nervous system) at the time of admission. Vascular
injuries were located in the cervical region in 11 patients, in the lumbar region in 3
and in the thoracic region in 1 patient. The lesions included arteriovenous fistula in
five, pseudoaneurysm in six and arterial dissection in four patients. The mechanism
of vascular injury included penetrating trauma in six, nonpenetrating trauma in five
and iatrogenic penetrating injury in the remaining four patients. Eleven patients were
treated endovascularly with persistent elimination of the vascular lesions associated
with symptom-free clinical follow-up, two patients were managed medically with a
good clinical follow-up and the remaining two were managed symptomatically.
Conclusion: The possibility of vascular lesion should be kept in mind when examining patients with spinal trauma, especially with fracture dislocation and penetrating
injury. Endovascular therapy allows the elimination of a majority of these potentially
dangerous lesions with good long-term clinical follow-up.
B-373
14:18
How to predict the site of arterial injury in unstable patients with pelvic
fractures by clinical and radiological parameters
J. Dormagen1, A. Tötterman2, O. Røise1, L. Sandvik1, N.-E. Kløw1; 1Oslo/NO,
2
Uppsala/SE (jobador@frisurf.no)
Purpose: To correlate clinical findings and fracture pattern on pelvic plain film (PXR)
in hemodynamically unstable trauma patients with pelvic angiography.
Methods and Materials: From 1995 to 2007, 95 patients (66 men) underwent
pelvic angiography due to suspected traumatic pelvic bleeding. Mean age was 44
(6-92) years. Fracture location was registered as anterior, posterior, right or left.
Arterial injuries (AI) were classified as involving anterior, posterior, right or left
pelvic branches of the internal iliac arteries. Multiple logistic regression was used
to correlate clinical data and fracture pattern with AI.
Results: AI were found in 82 patients (86%). Successful embolization was achieved
in 69/73 patients (95%). Motorcycle injury was a risk factor for anterior AI (OR 5.2,
95% CI 1.4-18.7), while car driver injury was associated with left AI (OR 5.5, CI
1.7-18.1). Hemoglobin level 8 g/ml was associated with multiple AI (OR 5.4, CI
1.7-17.7), as was heart rate 100 beats per minutes (OR 3.0, CI 1.1-8.6). Unilateral
fracture was associated with ipsilateral AI (right side OR 4.9, CI 1.4-17.3, left side
OR 12.0, CI 3.0-48.4) and bilateral fracture was associated with bilateral AI (OR
3.6, CI 1.2-10.7). The risk for multiple AI increased from 20% (one risk factor) to
70% (three risk factors).
Conclusion: Prior to angio-embolization of pelvic bleeding, the interventional
radiologist should take into account trauma mechanism, hemodynamic status and
fracture pattern for selection of access site and identification of AI.
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B-370
trajectory is then projected on the live fluoroscopy images. Ultrasound-inaccessible
lesions were included. At least a planning and a control cone-beam CT to check
for accuracy and complications was performed.
Results: Since the clinical introduction in October 2006, we performed 121 needle
interventions using live 3D-fluoroscopy guidance; 96 (79%) were diagnostic biopsies
with a definitive histopathological diagnosis of 94%. Therapeutically performed
interventions consisted of abscess drainages (n = 10), vertebroplasty (n = 5),
aspirations/nephrostomy (n = 6), embolization (n = 1) and localizations/infiltrations
(n = 3). The acceptable safety margin of the needle target was less than 5 mm.
Technical success was achieved in 100% checked by a control cone-beam CT. The
mean procedure time was 28:52 minutes and fluoroscopy time 3:42 min. There was
a minor, self-limiting complication in seven (5.8%) patients (small pneumothorax/
pain/bleeding). Accurate needle interventions with live 3D-fluoroscopy guidance
coregistered with previously acquired CT/MRI data is possible.
Conclusion: Live 3D-fluoroscopy guidance is a revolutionary new promising
technique used for needle interventions. Because of the C-arc architecture there
is optimal accessibility. It is accurate, quick and has little complications. The effective dose is significantly lower than that of CT and interventions based on previous
CT/MRI data are possible.
Scientific Sessions
B-374
14:27
Immediate and long-term outcomes of bronchial and non-bronchial artery
embolization for the management of haemoptysis
J.-Y. Chun, A.-M. Belli; London/UK (drjyc78@gmail.com)
Purpose: To evaluate the immediate and long-term results of arterial embolization from moderate to massive haemoptysis, and to identify factors influencing
outcome.
Methods and Materials: A retrospective analysis was carried out in 50 patients
who underwent transarterial embolization for haemoptysis between January 2002
and January 2008.
Results: There were 24 men and 26 women with a mean age of 55 years. The most
frequent causes of haemoptysis included bronchiectasis (16%), active tuberculosis
(12%) and aspergilloma (12%). A total of 126 bronchial and non-bronchial systemic
arteries were embolised in 62 procedures. Immediate cessation of haemoptysis
was achieved in 43 patients (86%). Cumulative haemoptysis control rates were
81.8% at 1 month, 69.9% at 1 year and 55.9% at 3-5 years. Haemoptysis remained
controlled in 36 patients (72%), recurred in 14 (28%) and 11 (22%) required repeat
embolization. Nine of the 14 (64.3%) recurrent cases occurred within the first month
of embolization. The worst outcomes were observed in aspergilloma patients where
all six suffered recurrent bleeding and three (50%) died from massive haemoptysis
within the first month. Aspergilloma was also associated with an increased risk of
haemoptysis recurrence (p 0.05). Complications of embolization included transient
chest pain, false aneurysm and one case of lower limb weakness.
Conclusion: Bronchial artery embolisation is an effective and safe procedure for
controlling haemoptysis. Non-bronchial and pulmonary arteries may contribute to
haemoptysis and these vessels should be actively sought, especially in cases of
recurrent or persistent haemoptysis. This is particularly important in aspergilloma,
which has a particularly poor prognosis.
B-375
14:36
Endovascular treatment of peripheral pulmonary artery pseudoaneurysms
and angiographic classifications with therapeutic implications
S. Shin, T. Shin, K. Jeon, J. Ryoo, H. Choi; Jinju/KR (s.suyoung@gmail.com)
Purpose: To classify peripheral pulmonary artery pseudoaneurysms (PAPs) based
on angiographic findings and to determine treatment options of the PAPs based
on the angiographic classification.
Methods and Materials: A total of 21 patients with massive hemoptysis had PAPs
that were detected on pulmonary CT angiography (CTA). Underlying diseases were
pulmonary tuberculosis (n = 14), fungus ball (4), lung abscess (2) and pneumonia
(1). All of the patients underwent bronchial, main pulmonary and selective pulmonary angiography. Type A (four cases) were defined as PAPs, visualized on main
pulmonary angiography. Type B (eight cases) were defined as PAPs, visualized on
selective pulmonary angioraphy, but not on main pulmonary angiography. Type C
(nine cases) were defined as PAPs not depicted on pulmonary angiography and
included PAPs visualized only with systemic angiography via the bronchopulmonary
shunt. For type A or B, successive embolization of the bronchial and pulmonary
arteries was performed. For type C, seven patients underwent bronchial arterial
embolization (BAE) alone and two patients underwent BAE and percutaneous
injection therapy.
Results: Type A or type B PAPs were successfully embolized and hemoptysis was
controlled in all patients. Hemoptysis was not controlled in one patient with a type
C who underwent only BAE.
Conclusion: For type A or B, successive bronchial and pulmonary arterial embolization is an effective treatment strategy. For type C, BAE with and without percutaneous
injection therapy seems to be an effective treatment. Therefore, classification of
PAPs based on angiographic findings is useful for the endovascular management
of PAPs with massive hemoptysis.
B-376
14:45
Stent-graft or Amplatzer vascular plug (AVP) with coils: Emerging
techniques for percutaneous treatment of visceral artery aneurysms
(VAAs)
A. Rebonato, M. Citone, L. Greco, N. Maltzeff, V. David, M. Rossi; Rome/IT
(albertorebonato@libero.it)
Purpose: Therapeutic strategy of VAAs, a rare disease with a high mortality rupture
risk, is still controversial. Use of stent-graft or AVP with coils is only occasionally
documented. The aim of this work is to evaluate efficacy and technical modalities
of these devices according to perioperative and long-term FU.
Methods and Materials: Between 2004 and 2008, 14 patients received an endovascular treatment for 10 splenic, 2 hepatic, 2 renal VAAs. Eleven patients had
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3-6 cm large aneurysms, and were treated with 2 self-expandable and 9 balloonexpandable stent-grafts. Three patients had 9-13 cm giant splenic aneurysms
(GSA):AVP was used to occlude the neck and cut up Teflon g.w. sheaths to fill
up the aneurysm. CT-angiography was performed before the procedure and after
discharge, at 6 and 12 months.
Results: In all cases, angiographic aneurysm exclusion was documented. In 1
case, a hilar splenic artery perforation with peritoneal bleeding was promptly treated
with coil-embolization. Patients treated with embolization and also 1/11 treated with
stent-graft, had segmental splenic infarction. One of theme, at 1 month, developed
4 cm splenic abscess, successfully treated with antibiotics. Post-procedure CT
showed complete aneurysms thrombosis and patency of stent-grafts. At a mean
26 months FU, only one 5 mm kinked endograft was occluded.
Conclusion: The stent-graft and the AVP are useful emerging endovascular tools
in VAAs treatment. The former are fully respective of vascular anatomy while the
latter are faster and safer to use, reducing procedure time and avoiding risk of
device distal migration. Long term FU appear to confirm durability of the aneurysm
thrombosis.
B-377
14:54
Preoperative portal vein embolization using an Amplatzer vascular plug
H. Yoo, G.-Y. Ko, D. Gwon, J. Kim, H.-K. Yoon, K.-B. Sung, S. Hwang, S.-G. Lee;
Seoul/KR (yhk_00@yahoo.co.kr)
Purpose: To evaluate the safety and efficacy of preoperative portal vein embolization (PVE) using an Amplatzer vascular plug (AVP).
Methods and Materials: A total of 41 patients who underwent PVE using gelatin
sponge particles and an AVP were enrolled. The right portal branch was punctured
with a 21-gauge needle and then a 6-8 F sheath was introduced. The right portal
branches were embolized using gelatin sponges (1-8 mm3 in size) through a 5 F
catheter initially and then the AVP was deployed at the first or second order right
portal vein. Technical success and complications, recanalization, change in the
total estimated liver volumes (TELV), future liver remnant (FLR) and FLR/TELV
were evaluated. Follow-up CT was obtained 1-43 days (median 16) after PVE for
evaluation of the volume parameters.
Results: PVE was technically successful in 40 of 41 patients. Major complications
occurred in two patients including extensive portal vein thrombosis owing to AVP
migration and liver abscess, respectively. Partial recanalization of occluded portal
vein was seen in one patient. Pre- and post-PVE, the mean volumes of the FLR
and the ratio of the FLR/ TELV were 532 ml p 154, 653 ml p 174 (P 0.001) and
36% p 7, 43% p 8 (P 0.001), respectively.
Conclusion: PVE using the AVP seems to be a relatively safe and effective modality
for inducing hypertrophy of the FRL with minimal risk of recanalization. However,
one should keep in mind the risk of extensive thrombosis owing to AVP protrusion
into the main portal vein.
B-378
15:03
Interventional radiological procedures in the treatment of complications
after liver transplantation: Nineteen years of experience
P. Hallscheidt, R. Lopez-Benitez, H.-U. Kauczor; Heidelberg/DE
(hallscheidt@yahoo.de)
Purpose: The aim of this study is to evaluate interventional radiological procedures (IRP) in liver transplant (LTX) patients. These include procedures for biliary,
arterial, venous and portal complications, as well as the treatment of infected and
noninfected fluid collections.
Methods and Materials: This retrospective study covered 583 patients (mean
age: 44p14 years) in whom a total of 685 LTX were performed from August 1987
to April 2005.
Results: Overall, 182 LTX patients underwent a total of 428 IRP, including digital
subtraction angiography (DSA) (n=152 /35.51%), percutaneous transluminal
angioplasty (PTA) (n=4 /0.93%) and PTA + stent (n=7 /1.63%) of arterial anastomosis, PTA + stent of the celiac trunk (n=2 /0.46%), transjugular intrahepatic
portosystemic shunt (TIPSS) (n=2 /0.46%), arterial lysis (n=4/0.93 %), venous
lysis (n=2/0.46%), inferior vena cava stenting (n=2/0.46%), percutaneous biliary
drainage (PCBD) (n=34/7.94%), percutaneous transluminal dilatation (PTD) of the
biliodigestive anastomosis (n=16/3.73%), biliary stent (n=5/1.16%), intrahepatic
biliary flushing treatment (IBFT), stone and cast biliary extraction (n=27 /6.30%),
other interventions (e.g., embolization in other regions, transjugular liver biopsies,
lymphangiographies) (n=9 /2.10%), and ultrasound (US)- and computer tomography
(CT)-guided biopsies and percutaneous drainage (n=153 /35.74%). The overall
success rate was 85.7%.
Conclusion: Technical improvements in LTX and interventional radiology permit
vascular and biliary complications to be treated successfully by interventional
radiology.
Scientific Sessions
B-379
15:12
Percutaneous transhepatic liver biopsy with gelfoam tract embolisation:
Efficacy and safety
E.T.H. Liu, S.K. Venkatesh; Singapore/SG (eugliu2002@yahoo.com.sg)
B-380
15:21
High field MR-guided biopsies with a new MR-compatible assistance
system: Technique and first results
S. Zangos, K. Eichler, M.G. Mack, C. Müller, M. Heller, A. Thalhammer, T.J. Vogl;
Frankfurt a. Main/DE (zangos@em.uni-frankfurt.de)
Purpose: The purpose of this study was to examine the feasibility and safety of
MR-guided biopsies in patients with suspicious lesions using a new MR-compatible
assistance system in a high-field MR-system.
Methods and Materials: A total of 20 patients with suspicious focal prostate
lesions detected by high-field MR imaging and 5 patients with retroperitoneal
lesions were biopsied in a high-field MR-system (1.5 T, Sonata, Siemens) using
a new MR-compatible assistance system (Innomotion; Innomedic; Herxheim).
The procedures were guided using T1-weighted FLASH and T2-weighted TSE
sequences. A servopneumatic drive moves the AMO to the insertion point. The
physician introduced the punction needle manually and biopsies were taken in
coaxial technique through a 15-gauge pencil tip with a 16-gauge biopsy handy.
Complications and biopsy findings were documented.
Results: An accurate punction could be easily performed using this new system in
a high-field system. No side effects or complications were observed in all patients.
Pathological findings revealed sufficient probes in 24 cases and insufficient material
in 1 case, due to technical problems with the biopsy device. This problem was corrected with a modification of the software. The T2-weighted images are superior for
the evaluation of the anatomy and the needle position during the interventions.
Conclusion: Our results indicate that this MR-guided assistance system is suitable for an accurately needle placement for histological clarification of suspicious
prostate retroperitoneal lesions in a high-field MR system.
Room G/H
Head and Neck
SS 708
Developmental, autoimmune and parotid disorders
Moderators:
J.A. Castelijns; Amsterdam/NL
C. Schüller-Weidekamm; Vienna/AT
B-381
14:00
Fetal MR imaging of cranio-facial and neck mass lesions and utility of cine
sequence
K. Shekdar, T. Feygin, L. Bilaniuk, R.A. Zimmerman; Philadelphia, PA/US
(shekdar@email.chop.edu)
Purpose: The purpose of our study is to demonstrate the utility of MR imaging
of fetal cranio-facial and neck anomalies with particular reference to cine imaging
technique.
Methods and Materials: We retrospectively reviewed 115 fetal MR examinations
performed at our institution, in patients with suspected head and neck anomalies
by ultrasonography, during the time period September 2000 to June 2007. The fetal
age ranged from 19 to 32 weeks. All studies were performed on 1.5 Tesla Siemens
MAGNETOM Vision and Avanto Systems.
Results: The spectrum of head and neck masses in our patient series included:
cervical lymphangiomas, cervical and skull base teratomas, cervical veno-lymphatic
malformations, thyroglossal duct cyst, cleft lip and palate and arachnoid cyst of the
skull base. Cases of craniosynostoses are also incuded in the series. MR imaging
provided morphological information for better characterization of the masses. It also
provided information regarding fetal swallowing and airway obstruction.
Conclusion: Fetal MR imaging along with cine imaging technique is very useful in
delineation of cranio-facial and neck lesions. Cine imaging provides critical information regarding fetal swallowing and airway obstruction. This information is valuable in
guiding in utero management and in planning delivery and postnatal management.
B-382
14:09
The face predicts the brain: The association of facial malformations and
brain anomalies in fetuses with trisomy 13 in fetal MRI
S.F. Nemec, P.C. Brugger, C. Koelblinger, C. Czerny, D. Prayer; Vienna/AT
Purpose: Since the 1960s, the literature describes that congenital facial malformations can predict brain anomalies. Therefore, findings in facial malformations
in fetuses with trisomy 13 were reviewed in fetal MRI, which allows visualizing the
viscero-neuro-cranium and were correlated with potential brain anomalies.
Methods and Materials: This retrospective study included ten fetuses (16-34
gestational weeks) with trisomy 13 and facial malformations, depicted in fetal MRI.
In addition to a standard MRI protocol, the following dedicated sequences were
used to image the viscero-neuro-cranium: An axial T1-weighted (w) sequence; axial,
coronal and sagittal T2-w sequences; a 3D thick-slab T2-w sequence; a coronal
single shot fast field echo sequence; and axial and coronal diffusion weighted
imaging. The evaluation focused on facial and brain structures and, additionally,
on extracranial organ systems.
Results: Midface malformations that consisted of cyclopia (one), microphthalmia
(one) and hypotelorism (four); of arhinia (four), proboscis (two) and flat nose (two);
and of median facial cleft (one) and lip-palate-jaw clefts (five) were associated with
semilobar (six) and alobar (two) holoprosencephaly. Furthermore, MRI demonstrated pachygyria (four), a missing olfactory nerve (six), a missing optic nerve (one),
a frontoethmoidal meningoencephalocele (one), an epipharyngeal meningocele
(one) and small liquor spaces (one), respectively. Extracranial malformations were
seen in all ten fetuses.
Conclusion: As fetal MRI is able to demonstrate both - facial and brain anomalies - in trisomy 13, the clinical concept of “The face predicts the brain.” can be
also reversed to “The brain predicts the face.” reflecting the evolutionary unity of
facio-cranial malformations.
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Purpose: To determine the efficacy and safety of the use of gelfoam tract embolisation following percutaneous transhepatic liver biopsy.
Methods and Materials: A total of 165 patients who underwent percutaneous
liver biopsy over a 1.5 year period were retrospectively reviewed. Biopsies were
performed with either 15- or 18- gauge automated core biopsy needle. Track
embolization with gelfoam was performed in 46 patients considered to be at high
risk for bleeding. All patients were followed up for a minimum period of 24 hours
post procedure. The data collected included patient’s demographics, indications
for liver biopsy, number of needle passes performed and histological description
of the specimens.
Results: Histological tissue samples obtained per procedure ranged from 1 to 6
(mean 3.1 sample). A total of 210 and 123 liver biopsy samples were obtained from
those without and those with gelfoam track embolization, respectively. Accurate
tissue diagnosis was achieved in all cases (100%). Complications observed include
hemoperitoneum, local bleeding and pain. Six complications (2.8% per sample) were
encountered in those where non-gelfoam cases compared with four complications
(3.2% per sample) encountered where gelfoam was used. This is comparable with
complication rates published in literature for transhepatic biopsies studies without
embolisation and normal coagulation profile, which range from 0.1 to 3.6% and
better than the transjugular route with a complication rate of up to 9%.
Conclusion: Percutaneous liver biopsy with track embolisation using gelfoam plugs
is a safe technique with low complication rate and a safer alternative to transjugular
biopsies in patients with coagulopathy.
14:00 - 15:30
Scientific Sessions
B-383
14:18
Sphenoid sinus ectopic pituitary adenomas: CT and MRI findings
B. Yang; Beijing/CN (cjr.yangbentao@vip.163.com)
Purpose: To study the computed tomography (CT) and magnetic resonance imaging
(MRI) features of sphenoid sinus ectopic pituitary adenomas (EPAs).
Methods and Materials: A retrospective review of 249 imaging-detected sphenoid
sinus lesions over a 6-year period revealed eight patients with histology-proven
EPAs. All eight patients underwent CT and MRI. The following imaging features
were reviewed: (a) size, (b) margin, (c) CT attenuation characteristics and (d) MRI
signal intensity. In addition, the involvement of adjacent structures and the timeintensity curve (TIC) of dynamic MRI were analysed.
Results: Sphenoid sinus EPAs constituted 3% of the sphenoid sinus lesions in
this series. All EPAs have well-defined margins and show no relationship to the
intrasellar pituitary gland. The mean size is 28 mm (range, 20-46 mm). On nonenhanced CT, the lesions appear as isodense to gray matter in seven (88%) and
hypodense in one (12%) patient. On T1WI, EPAs appear to be isointense in six
(75%) patients and hypointense in two (25%) patients. On T2WI, the lesions appear to be hyperintense in two (25%) patients and isointense in six (75%) patients.
EPAs show moderate heterogeneous contrast enhancement. Two patients had
dynamic contrast enhancement MRI and the TIC showed rapid enhancing and
slow wash-out pattern. The following features are also seen: (i) empty sella (five
patients, 62.5%), (ii) bone changes (five patients, 62.5%), and (iii) involvement of
cavernous sinus (five patients, 62.5%).
Conclusion: A high index of suspicion for EPAs and a familiarity with imaging
findings may help to accurately diagnose this rare entity.
B-384
14:27
Wegener granulomatosis of the paranasal sinuses and temporal bone: Is
MRI worth using?
D. Farina, R. Longaretti, M. Ravanelli, A. Borghesi, R. Maroldi; Brescia/IT
(nappaje@yahoo.it)
Purpose: To assess the role of MRI in detecting paranasal sinuses (PNS) and
temporal bone (TB) involvement in Wegener granulomatosis (WG).
Methods and Materials: MRI examinations of 37 consecutive patients affected by
WG in its active phase were retrospectively reviewed. MRI protocol included TSET2,
SET1 and, after contrast application, both 3DGE and SET1. PNS and TB lesions
were scored as: aspecific, when signal pattern was indistinguishable from aspecific chronic inflammation; specific, when masses were detected, when mucosal/
submucosal hypo-T2 lesions were seen in the PNS and when enhancement was
detected in the TB. In all cases, MRI and clinical findings were matched.
Results: Of 37 patients, 22 (59.4%) had clinical signs and symptoms of PNS
involvement: MRI showed specific findings in 13/37 (10/13 symptomatic) and was
negative in 7/37 (4/13 symptomatic). In 17/37 (9/17 symptomatic) with aspecific
findings, MRI was inconclusive for the presence of PNS involvement. Symptoms
of TB involvement were recorded in 15/37 (40.5%) patients: MRI showed specific
findings in 5/37 (all symptomatic) and ruled out lesions in 19/37 (4/19 symptomatic).
In 13/37 (6/13 symptomatic) patients with aspecific findings, MRI was inconclusive
for TB involvement.
Conclusion: MRI may rule in/out PNS involvement in 54.1% of patients. This can
be valuable given the low success of nasal mucosa biopsies. Furthermore, when
showing inconclusive findings, MRI may indicate the site for a biopsy, thus increasing
the rate of success of the procedure. Additionally, in TB (routinely included in axial
scans of the PNS), MRI may rule in/out the disease in 64.1% of patients.
B-385
14:36
Comparison of duplex sonography and high-resolution MRI in giant cell
(temporal) arteritis
T.A. Bley1, M. Reinhard2, C. Hauenstein2, M. Markl3, K. Warnatz2, A. Hetzel2,
M. Uhl2, M. Langer2; 1Madison, WI/US, 2Freiburg/DE, 3Feiburg/DE
(markus.uhl@uniklinik-freiburg.de)
Purpose: Noninvasive diagnosis of giant cell arteritis (GCA) is a challenge. Temporal
artery biopsy (TAB) is considered to be the diagnostic gold standard. The purpose of
this study was to compare the diagnostic performance of two noninvasive imaging
modalities, high-resolution magnetic resonance imaging (MRI) and color-coded
duplex sonography (CCDS) in diagnosing GCA.
Methods and Materials: The results of MRI studies and CCDS in 59 patients with
suspected giant cell arteritis were compared with the final clinical diagnosis (based
on the ACR criteria and 6-month follow-up observation). Sensitivity, specificity
and positive and negative predictive values (PPV, NPV) were calculated for either
method. In 41 of the patients, imaging results were also compared with findings of
temporal artery biopsy (TAB).
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Results: Of the 59 patients, 36 (61%) were finally diagnosed with giant cell arteritis.
Sensitivity of MRI (CCDS) was 69% (67%), specificity 91% (91%), NPV 66% (64%)
and PPV 92% (92%). TAB was positive in 24 of the 41 biopsied patients (59%).
Sensitivity of MRI (CCDS) compared with TAB was 83% (79%), specificity 71%
(59%), NPV 80% (73%) and PPV 75% (67%). The differences between MRI and
CCDS were not significant.
Conclusion: Both noninvasive imaging modalities, CCDS and MRI, have comparably high sensitivities and specificities in the detection of mural inflammatory changes
in GCA compared with the final clinical diagnosis and also with the diagnostic gold
standard of TAB. Each of the two has its own advantages and disadvantages, which
need to be evaluated with regard to the local setting.
B-386
14:45
Involvement of the ophthalmic artery in giant cell arteritis visualized
by 3 T MRI
J. Geiger1, T. Neß1, M. Uhl1, W.A. Lagrèze1, P. Vaith1, M. Langer1, T.A. Bley2;
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Freiburg/DE, 2Madison, WI/US (julia.geiger@uniklinik-freiburg.de)
Purpose: To retrospectively analyze inflammatory involvement of the ophthalmic
arteries in patients with giant cell arteritis (GCA) utilizing high-resolution magnetic
resonance imaging.
Methods and Materials: A cohort of 50 patients with proven giant cell arteritis
(GCA) who had been examined by 1.5 or 3 T high-field MRI was analyzed retrospectively in a consensus reading for possible involvement of the ophthalmic arteries.
In 43 patients, entire orbits were within the field of view. In all cases, the superficial
cranial arteries displayed mural inflammation in postcontrast-T1 weighted spin-echo
(SE) images. MRI results were compared with ophthalmologic findings, subjective
visual symptoms and laboratory, i.e. C-reactive protein (CRP) and erythrocyte
sedimentation rate (ESR) values.
Results: We observed mural contrast enhancement of the ophthalmic arteries in
20/43 patients (46%). Bilateral involvement was seen in 14, unilateral enhancement in six cases. 15 patients had ophthalmic vascular diseases: nine had anterior
ischemic optic neuropathy (AION), one posterior ischemic optic neuropathy (PION),
four revealed central retinal artery occlusion (CRAO) and one patient presented with
narrowing of the retinal arteries. Funduscopy detected no arteritis-related changes
in 22 cases. Of those patients who were MRI positive, seven had ophthalmological
disease. 26 patients complained of visual symptoms including amaurosis fugax,
vision loss, diplopia or eye pain.
Conclusion: High-resolution MRI detects mural contrast enhancement consistent
with inflammatory changes in the superficial cranial and extracranial arteries and
additionally in the ophthalmic arteries. This provides insight in vasculitic orbital
involvement during one and the same investigation.
B-387
14:54
Color Doppler ultrasound assessment of blood flow velocities changes in
the central retinal artery of type 1 diabetic patients submitted to kidneypancreas, kidney-alone and islet-alone transplatation
M. Cellina, M. Venturini, C. Losio, P. Maffi, A. Secchi, A. Del Maschio; Milan/IT
(cellina.michaela@hsr.it)
Purpose: In long-term type 1 diabetic-uremic kidney-transplanted patients, pancreas
or islet transplantation can determine diabetes resolution. Islet-alone (IA) transplantation has been recently introduced for diabetic-non-uremic patients to prevent
diabetes-related complications such as retinopathy, characterized by endothelial
dysfunction, conditioning a reduction of central retinal artery (CRA) flow velocities.
Our aim was to compare CRA velocity changes in kidney-pancreas (KP), kidneyalone (KA) and IA patients after transplant.
Methods and Materials: CRA of 10 KP, 10 KA and 10 IA-transplanted patients
were evaluated with color Doppler ultrasound (CDU; ATL-HDI5000, 5-12 MHz linear
probe) by the same operator before and 2 years after transplantation. Peak systolic
(psv) and end diastolic (edv) velocities were measured for each central retinal artery
at the retrobulbar level and expressed as the mean of both eyes.
Results: All groups showed similar CRA velocities at baseline. At 2 years, the
KP and KA groups did not show a significant increase of CRA velocities (KP-psv:
5.73 p 1.75 vs 6.06 p 1.44; KP-edv: 1.68 p 0.31 vs 2.0 p 0.44; KA-psv: 4.55 p 1.42
vs 5.74 p 2.06; KA-edv: 1.68 p 0.54 vs 1.57 p 0.39, P = ns). A statistically significant
increase in CRA velocities was found only in IA patients, with significantly higher
values than KP and KA (IA-psv: 10.12 p 1.20 vs 6.09 p 0.46, P 0.01; IA-edv:
2.99 p 0.48 vs 1.65 p 0.07, P = 0.02).
Conclusion: CDU allows quantitative and reproducible measurements of CRA
blood flow velocities. A significant improvement of CRA flow velocities was evident
only in IA-transplanted patients and not in KP patients, despite diabetes resolution
in both groups. Probably, a reversal of endothelial dysfunction in retinal microcirculation is less likely in patients affected by a longer duration of diabetes, with related
uremia and microvascular complications.
Scientific Sessions
B-388
15:03
Value of apparent diffusion coefficient calculation before and after
gustatory stimulation in the diagnosis of acute or chronic parotitis
T. Ries, C. Arndt, M. Regier, J. Graessner, M.C. Cramer, M. Jaehne, G. Adam;
Hamburg/DE (ries@uke.uni-hamburg.de)
B-389
15:12
MRI of the parotid gland and duct at 7 Tesla: Better than 1.5 Tesla?
O. Kraff, J.M. Theysohn, S. Maderwald, P.C. Kokulinsky, H.H. Quick, Z. Dogan,
M.E. Ladd, E.R. Gizewski, S.C. Ladd; Essen/DE (oliver.kraff@uni-due.de)
Purpose: To optimize the sequences for high-field MR imaging of the parotid gland
and duct at 7T to discuss the potential of high-field imaging in patients.
Methods and Materials: A 7T whole-body scanner was used in combination with
a 10-cm-diameter loop coil. Various GRE (MEDIC, DESS, 3D-FLASH) and TSE
(PD/T2, STIR) sequences were optimized and subsequently tested on 4 healthy
volunteers and 12 patients. High-resolution images were compared with 1.5 T
images both quantitatively (SNR, CNR) and qualitatively (visual rating of two
independent readers).
Results: All examinations were completed within 30 min. The high 0.6 mm isotropic resolution of 3D-DESS was very useful to define an oblique orientation with
most of the duct being in-plane for subsequent imaging. MEDIC displays very fine
branches of the duct; furthermore, MEDIC yields a very good depiction of lymph
nodes. Severe SAR problems were observed with the STIR sequence at 7T. Gland
tissue in tumor patients can be well characterized with the PD/T2 TSE. Intravenous
contrast agent administration in combination with the 3D-FLASH sequence renders
even better delineation of various tumor types at 7T. Highest CNR between duct
and gland was achieved with the 7T DESS; MEDIC yielded 5.4 times higher CNR
at 7T compared to 1.5 T. At 1.5 T, only the STIR sequence showed comparable
quality to the overall superior 7T sequences.
Conclusion: Within an acceptable time, MR imaging at 7T provides excellent image contrast and resolution of the parotid gland and duct, which is mirrored by the
much higher rated image quality.
B-390
15:21
Image fusion between EP-DWI and post-gadolinium isotropic 3D VIBE
sequences in the head and neck: Feasibility study
M. Ravanelli1, D. Farina2, A. Giugno2, R. Monesi2, R. Maroldi2; 1Martinengo/IT,
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Brescia/IT (marcoravanelli@hotmail.it)
Purpose: When examining H&N lesions, the correlation of EP-DW signals with
anatomical structures is often a critical issue, given the low spatial resolution and
susceptibility artifacts. Therefore, the precise correlation between findings in EP-DWI
and conventional high-resolution sequences is mandatory. The fusion of EP-DWI
and isotropic 3D GE T1 (VIBE) post-Gd sequences may combine the strengths of
both functional and volumetric imaging. Feasibility and accuracy of image fusion
is the aim of the study.
Methods and Materials: Twenty consecutive patients underwent MR for a primary
head and neck neoplasm. MR protocol included EP-DWI and isotropic 3D VIBE
sequences. Fusion matching was first performed between b0 and 3D VIBE images;
co-registration parameters were then applied to b1000 images; a further tuning
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Physics in Radiology
SS 713
Structural and functional imaging
Saturday
Purpose: To investigate the value of diffusion-weighted (DW) echo-planar imaging
(EPI) for quantifying physiological changes of the parotid gland before and after
gustatory stimulation in patients suffering from acute or chronic recurrent inflammation in comparison with healthy volunteers.
Methods and Materials: Using a DW-EPI sequence at 1.5 T parotid glands of 19
consecutive patients with acute (n = 14) and chronic (n = 5) inflammation of the
parotid glands and 52 healthy volunteers were examined. Magnetic-resonance
(MR) images were obtained before and after gustatory stimulation with 5 cc of
lemon juice.
Results: In volunteers, mean ADC values of 1.14 × 10-3 mm2/sec before and 1.2 ×
10-3 mm2/sec after gustatory stimulation were observed. In acute inflammation, ADC
values were higher before (1.22 × 10-3 mm2/sec (P = 0.006)) and after stimulation
[1.32 × 10-3 mm2/sec (P 0.001)]. Before stimulation ADC differences between
chronic inflammation (1.05 × 10-3 mm2/sec) and healthy volunteers (P = 0.04) as
well as between acute and chronic inflammation were statistically significant (P =
0.005). No differences were detected after stimulation between chronic inflammation (1.2 × 10-3 mm2/sec) and healthy volunteers (P = 0.94) and between acute and
chronic inflammation (P = 0.15), respectively.
Conclusion: DW-EPI seems to display the physiological changes of the parotid
gland in patients suffering from acute or chronic inflammation and might be useful
in discriminating healthy from affected glands.
was finally performed between b1000 and VIBE images, using as landmarks the
hyperintense structures on b1000 images, except tumor. Mismatch between the
center of these structures on b1000 and 3D VIBE images was measured in all three
major axes using “side by side” visualization modality.
Results: Matching between b1000 and 3D VIBE images was performed on 161
anatomical structures (8.5/examination). Mean mismatch on antero-posterior direction (phase-encoding direction) was 1.82 mm (95% CI 0.21 mm); on transversal
direction it was 0.74 mm (95% CI 0.08 mm); on cranio-caudal direction it was
0.85 mm (95% CI 0.09 mm).
Conclusion: Image fusion between EP-DW and isotropic 3D VIBE sequences is a
feasible and accurate technique and may represent an important tool for oncological
imaging in the head and neck region.
Moderators:
T.D. Fryer; Cambridge/UK
A. Todd-Pokropek; London/UK
B-391
14:00
A step towards perfusion benchmark measurements in clinical imaging
devices
P. Deman1, T.Y. Lee2, H. Elleaume1, A. Krainik1, J. Le Bas1, F. Esteve1, J. Adam1;
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Grenoble/FR, 2London, ON/CA (deman@esrf.fr)
Purpose: New methods aiming to assess quantitative brain perfusion have been developed, based on tracer kinetics models for the extraction of perfusion values. The results
vary with the imaging technique, protocols, algorithms and operators. In particular, it is
not known to what extent blood brain barrier leakage affects the results.
Methods and Materials: As a necessary step towards validating absolute perfusion measurements procedures, we develop a novel method usable with both CT
and MRI based on a phantom that mimics perfused tissue under defined conditions. This is a bundle of porous capillaries each about 215 microns in diameter.
Theoretical permeability surface (PS), fluid volume and flow are derived from the
phantom physical characterization and can be compared with those calculated with
the models implemented in workstations. These models have been tested under
various input flow rates and sizes of contrast agent.
Results: The adiabatic approximation of the Johnson & Wilson model returned
the closest fluid flow and volume on a reference scan (17.4p4.5 ml/100 g/min
and 21.2p1.5 ml/100 g, respectively) compared to the theory (19.8 ml/100 g/min
and 22.9 ml/100 g, respectively). This model was also able to retrieve PS values
for two contrast agents' sizes: 7p13 ml/100 g/min for baryum (Micropaque®) and
44p10 ml/100 g/min for iodine (Iomeron®). The gamma variate model gave relative
errors 350% for the smallest contrast agent.
Conclusion: To our knowledge, this is the first report of an objective method aiming
to validate the CT or MRI perfusion measurement procedures, and shedding the
light on controversial absolute perfusion measurements tools.
B-392
14:09
Multiple spatial frequency band filtering of whole brain perfusion CT data:
Dose reduction and improved spatial resolution
E. Klotz1, R. Raupach1, H. Fichte1, B. Schmidt1, T. Flohr1, M. Lell2; 1Forchheim/DE,
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Erlangen/DE (ernst.klotz@siemens.com)
Purpose: To improve the contrast to noise ratio (CNR) of whole brain perfusion CT
scans with the aim to reduce radiation exposure or increase spatial resolution.
Methods and Materials: We extended a commercial brain perfusion CT package
(Siemens, Germany) equipped with 3D motion correction by a dedicated multiple
spatial frequency band filter (MSBF). The filter is applied after motion correction
and reduces noise power without impairing the resolution of temporal changes.
We retrospectively reconstructed standard whole brain perfusion data (10 cm
coverage) of 20 patients with cerebral ischemia or tumors with slice thicknesses
between 1.5 and 10 mm. We compared the perfusion parameters calculated from
thin slice recons with MSBF with the ones calculated from thick slices without
MSBF. Absolute values of CBF, CBV and MTT and their standard deviation in
normal and pathological areas were determined to estimate CNR improvement
in routine clinical data.
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Results: Quantitative perfusion parameters were not significantly different between
1.5 / 3 mm (MSBF) and 6 / 10 mm (no MSBF) slices, respectively. Standard deviation
was comparable or smaller. This corresponds to a CNR improvement of about a
factor of 2, which can either be used to reduce exposure, slice width or a combination of both without impairing perfusion parameter image quality.
Conclusion: The CNR of standard clinical whole brain perfusion CT data acquired
with continuous spiral scanning with variable pitch can be significantly improved.
MSBF filtering in conjunction with motion correction allows either reducing radiation
dose or increasing z-resolution by up to a factor of four.
B-393
14:18
Colour CT X-ray spectroscopic images of mice using Medipix-2 detector
N.G. Anderson1, A.P. Butler1, N. Scott1, N.J. Cook1, J. Butzer1, N. Schleich1,
M. Firsching2, P.H. Butler1; 1Christchurch/NZ, 2Erlangen/DE
(nigel.anderson@otago.ac.nz)
Purpose: In the future, X-ray biomedical imaging will combine spectroscopic with
spatial and temporal and density information to allow tissue characterisation and
quantification in 3D image using one X-ray source. The aim of our study was to
produce 3D spectroscopic images of a mouse using a Medipix-2 detector.
Methods and Materials: We have built a desktop X-ray spectroscopic CT scanner using the Medipix-2 detector (MARS). We imaged six mice, mean weight 30 g
(range 27-34 g). The mice were lethally anaesthetised with pentobarbitone at the
time of injecting contrast agent directly into the heart (0.5 mL) or pleural space
(0.5 mL) or bronchial tree (0.2 mL). Barium sulphate and Lipiodol were used. The
dead mice were preserved in resin then imaged in the scanner at 75 keV; tube
current was nominally 0.079 mA.
Results: We were able to discriminate the different contrast agents in the bronchial
and vascular tree with high resolution, displaying calcium and iodine as different
colours on the same image. We could discriminate the vascular anatomy of the
mouse kidney down to interlobar vessels spatially (0.055 mm) and spectroscopically. Calcium was differentiated from contrast. Excellent soft tissue contrast was
achieved. Multiple images will be shown to demonstrate this. We expect to differentiate barium and iodine shortly.
Conclusion: Our novel X-ray spectroscopic scanner provides 3D spectroscopic
images of the mouse that can distinguish calcium and different contrast agents
within adjacent very small vessels at low radiation dose. This has wide potential
for human imaging including vascular imaging, detecting microcalcifications, tissue
characterisation and quantification.
B-394
14:27
Automatic intrinsic method for combined respiratory and cardiac gating in
small animal cone-beam CT
J. Kuntz1, J. Dinkel1, S. Zwick1, M. Grasruck2, F. Kiessling3, W. Semmler1,
S.H. Bartling1; 1Heidelberg/DE, 2Forchheim/DE, 3Aachen/DE (j.kuntz@dkfz.de)
Purpose: To develop a retrospective projection-based method for completely automatic intrinsic respiratory and cardiac gating, to reduce the complexity of scanning
processes and the influence of potential external interferences.
Methods and Material: Projection data of both mice (10) and rats (10) were
acquired using a prototype flat-panel cone-beam CT system. To extract the gating
signals out of the projection data, a region of interest (ROI) was placed to cover
diaphragm and heart. The diaphragm was found by detecting the maxima in difference images of projections from several rotations at same or similar angular
positions. Within this ROI the center of mass was calculated and plotted over projection positions. After band-pass filtering with appropriate cardiac and respiratory
frequencies resorting of the projection data was performed with respect to the gating
signal. This resulted in a phase-sensitive reconstruction. To evaluate the developed
method, intrinsic data (image quality, functional parameters and gating signals) were
compared with a simultaneously acquired extrinsic gating gold-standard.
Results: Automatic, intrinsic gating worked reliable in all cases. Gating signals of
automatic intrinsic and extrinsic gating correlated well. Image quality and functional
parameters were equivalent using both gating methods. High-quality reconstruction
of 4D cine series was possible.
Conclusion: The developed method enables a fully automatic cine reconstruction
of animals’ respiration and cardiac motion only from projection data itself. It is scanner independent and can be ported to other cone beam scanner systems, making
external gating hardware or manual interaction superfluous.
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B-395
14:36
Quantitative tissue characterisation in dual energy computed tomography
J.K. Van Abbema, M.J.W. Greuter, W. Kristanto, M. Oudkerk; Groningen/NL
(m.j.w.greuter@rad.umcg.nl)
Purpose: Validation of a model for quantitative tissue characterization by assessment of effective atomic numbers and electron densities from tomographic
reconstructions of dual energy CT (DECT).
Methods and Materials: A model was developed using a parameterization of the
linear attenuation coefficient. The model can be used to calculate the effective atomic
number and electron density based on CT numbers from DECT images. The model
was validated for 16 chemical substances (effective atomic numbers ranging from
5.47 to 12.96 and electron densities ranging from 2.20 to 4.12 × 1023 electrons/cm3)
by combining 80 kV and 140 kV data sets from a dual source CT.
Results: The calculated effective atomic numbers for the 16 substances correlated
well with the actual effective atomic numbers (Pearson’s chi-square value of 0.55,
deviation -10.8 to 9.3%). The calculated effective electron densities correlated
very well with the actual effective electron densities (Pearson’s chi-square value
of 0.005, deviation -1.6 to 2.5%).
Conclusion: The proposed model can be used as a quantitative tool for tissue
characterization in DECT.
B-396
14:45
Dedicated phase-correlated small animal micro-CT imaging
D. Ertel, Y. Kyriakou, M. Mronz, R.M. Lapp, W.A. Kalender; Erlangen/DE
(dirk.ertel@imp.uni-erlangen.de)
Purpose: To validate the performance of a phase-correlated image reconstruction
procedure with respiratory gating for small animal micro-CT imaging.
Methods and Materials: Small animal imaging using micro-CT systems provides
high spatial resolution, but often suffers from motion artifacts due to respiratory
motion. External synchronization signals are not always available and a phasecorrelated reconstruction cannot be performed. We generate a dedicated synchronization signal using a raw data-based motion function (kymogram) correlating
with the respiratory motion, based on a center-of-mass tracking on the flat panel
detector. Ten measurements of free breathing rodents were performed on a dualsource micro-CT scanner (Tomoscope 30s Duo, VAMP GmbH, Erlangen, Germany).
Projection data were acquired over ten rotations for multi-segment phase-correlated
reconstruction, i.e. using projection data of the same respiratory phase covering a
complete rotation for image reconstruction. Motion artifacts in the phase-correlated
images were analyzed to evaluate the reliability of our method.
Results: The kymogram approach provided a reliable synchronization signal
correlating with the respiratory motion cycle. Phase-correlated images showed
an improved image quality, above all in the diaphragm region, with respect to
motion artifacts. Here, object resolution was increased due to reduced smearing
artifacts. Image noise was increased typically by a factor of three, which was in
good agreement with the quadratic dependence on the number of rotations. There
was a reduction in data from ten rotations down to a single one.
Conclusion: We conclude that kymogram-based small animal CT imaging is
feasible with micro-CT. Ways to reduce the number of rotations are under investigation.
B-397
14:54
X-ray phase contrast imaging: Visualization of architectural properties of
human articular cartilage
P. Coan1, A. Bravin1, E. Muetzel2, D. Habs3, M.F. Reiser2, C. Glaser2; 1Grenoble/FR,
2
Munich/DE, 3Garching/DE (coan@esrf.fr)
Purpose: Identification of fine structural details and disruption in collagenous fibre
architecture within cartilage is important to diagnose early osteoarthritis (OA).
Thus, high-resolution imaging allowing for three-dimensional analysis of tissue
structure is desirable. Over the last decades, X-ray phase contrast (PhC) imaging
has been introduced as an alternative radiographic approach to yield a markedly
stronger contrast than absorption radiography. The aim of our study was to apply
X-ray PhC imaging for the characterization of architectural properties of intact and
pathological cartilage.
Methods and Materials: Three healthy and one pathological cartilage on bone
cylinders from 4 human patellae have been imaged using the analyzer-based (ABI)
and the propagation-based (PBI) PhC imaging techniques. Both projection and
computed tomographic images at high resolution (25 keV, digital Frelon camera,
voxel size: 8³ and 46³ micron³) have been acquired and compared with scanning
electron microscopy of the same samples.
Scientific Sessions
Results: Phase contrast projections and CT showed excellent depiction of the
architecture of subchondral bone in both ABI and PBI modes. A zonal pattern
within the cartilage matrix similar to collagenous fibre orientation in SEM could
be visualized.
Conclusion: High resolution PhC imaging is able to reveal structural details in
cartilage tissues suggesting a high potential of phase contrast imaging for future
diagnostic workup of OA.
B-398
15:03
Evaluation of cross-scatter effects on rawdata-based tissue decomposition
in dual energy dual source CT (DE-DSCT)
M. Meyer, Y. Kyriakou, W.A. Kalender; Erlangen/DE
(michael.meyer@imp.uni-erlangen.de)
B-399
15:12
Removal of arterial wall calcifications in CT angiography using calciumiodine spectral decomposition with simultaneous multi-energy MDCT
A. Vlassenbroek1, G. Kafri2, Y. Bar2, L. Goshen2, P. Coulon3; 1Brussels/BE, 2Haifa/IL,
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Paris/FR (alain.vlassenbroek@philips.com)
Purpose: Arterial wall calcifications may hinder the visualization of the arterial
lumen in CT angiography. Our purpose was to demonstrate that iodine-selective
images obtained with simultaneous multi-energy MDCT may enable a better visualization of the arterial lumen.
Methods and Materials: A phantom was constructed in lucite with 3 cylindrical
holes representing arteries of various diameters and including hyperdense tubes
made of polyvinylchloride mimicking calcified plaques all around the vessel wall.
This phantom was filled with increasing concentrations of iodine and imaged on a
prototype of a multi-energy MDCT scanner (Philips Healthcare). Simultaneously
acquired data from 2 layers of detectors were reconstructed to reflect low energy
and higher energy attenuation from a single X-ray source. Iodine-selective images
were used after material separation to measure the lumen sizes and to compare
them to the known lumen sizes.
Results: All measurements performed from the CT images after removal of the
high density structures by thresholding showed a threshold- and concentrationdependent underestimation of the lumen size up to 100%. However an excellent
correlation was found between the lumen sizes measured from the iodine-selective
images at all iodine concentrations and the known lumen sizes (R 0.98), with an
underestimation less than 10%.
Conclusion: Our results suggest that iodine-selective images provided by multienergy CT enables an accurate visualization of the residual arterial lumen,which
would be otherwise hindered by the blooming of calcified lesions in the regular
CT image. This method is less subjective and more accurate than calcification
removal by thresholding.
15:21
Detection of occluded lung vessels using dual energy CT: A phantom
study
B. Krauss1, K. Otani2, B. Schmidt1, T. Flohr1; 1Forchheim/DE, 2Tokyo/JP
Purpose: To study whether dual energy CT can aid in the detection of PE in small,
peripheral vessels and to investigate the impact of motion.
Methods and Materials: The SOMATOM Definition (Siemens Healthcare, Forchheim, Germany) can be used for dual energy CT scans of the lung (14 x 1.2 mm,
0.33 s rotation time, 140 kV/80 kV, 50 mAs/213 mAs, pitch 0.5) in order to show the
iodine/blood ratio for vessels. Plastic tubes simulating lung vessels (0.75-5 mm diameter) were mounted inside an anthropomorphic thorax phantom (QRM, Möhrendorf,
Germany) and filled with water (occluded vessel) or iodine solution (5 ml Iopromide
300 per 100 ml; 618.7 HU / 329.0 HU at 80 kV/140 kV). Images were evaluated
with syngo dual energy (Siemens Healthcare). A QRM motion phantom provided
continuous vessel motion with 8.3 mm/s or heart motion (60 bpm, amplitude 2 cm).
For each scan, two reconstructions were performed (kernels D30f / B70f).
Results: CT-values in the weighted average images and dual energy evaluation
could distinguish water and iodine for 3 mm diameter. For 1.5 mm (water) and
1.0 mm (iodine) maximum CT-values in the axial slices were below -100 HU (B35f)
and above 500 HU (B70f), but dual energy could detect water down to 1 mm and
iodine down to 0.75 mm without errors. For continuous motion, water (1.5 mm) and
iodine (1 mm) were only distinguishable with dual energy; for heart motion, iodine
(5 mm) could be detected.
Conclusion: Dual energy scanning allows to assess the iodine content of small lung
vessels for which single energy CT-values are not conclusive; for the same scan, dual
energy evaluation is less sensitive to motion than CT-value-based diagnosis.
14:00 - 15:30
Room K
Pediatric
SS 712
Cardiothoracic
Moderators:
K. Foster; Birmingham/UK
D. Prayer; Vienna/AT
B-401
14:00
Low-dose ECG-gated DSCT angiography: Preoperative assessment of
complicated congenital heart disease
X.M. Wang, Z.P. Cheng, L.B. Wu, D.W. Wu, Y.H. Duan, B.T. Chao, C. Liu; Ji Nan/CN
(chengzhaoping110@sina.com)
Purpose:This study was performed to investigate the clinical value of low-dose
ECG-gated DSCT angiography in preoperative assessment of complicated congenital heart disease.
Methods and Materials: A total of 51 patients (mean age 3.2 p 2.56 years, range:
2 months-15years; male 28) with suspected complicated congenital heart disease
underwent both ECG-gated DSCT angiography and color Doppler echocardiography
(CDE). Individual low-dose ECG-gated DSCT scan parameters were used according to the patient’s weight. In addition to the CT axial slices, 3D reconstructions
such as volume rendering (VR) and multiple planar reformation (MIP) were used to
diagnose cardiac abnormalities. The results were compared based on the results
of surgical findings. Statistical analysis was performed to compare the ability of the
two modalities to evaluate the anomalies of major structures.
Results: A total of 182 cardiac deformities were confirmed by operations. The
accuracy of DSCT and CDE in the diagnosis of incardiac deformities (63) were
respectively 95.2 and 98.4%. DSCT was as accurate as CDE in revealing incardiac
deformities (C2 = 1.033, P 0.10). The accuracy of DSCT and CDE in extracardiac
deformities (119) were respectively 99.2 and 67.2%. DSCT was superior to CDE in
extracardiac deformities (C2 = 43.393, P 0.005). The mean CTDIvol of all patients
was 5.88 p 3.35 mGy.
Conclusion: Low-dose ECG-gated DSCT angiography was more sensitive in
evaluating the anomalies of systemic vessels, pulmonary vessels and coronary
artery. It is extremely valuable in planning operative procedures, especially in
patients with complicated congenital heart disease.
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Purpose: To evaluate the impact of cross-scatter between both systems in DEDSCT and to develop a correction algorithm to improve the accuracy of a dedicated
off-line raw-data based on the material decomposition.
Methods and Materials: Measurements were carried out at tube voltages of 140
and 80 kV on a Siemens SOMATOM Definition DSCT scanner. Cross-scatter was
measured by turning one tube off and reading out the corresponding detector.
Measurements were performed at mAs-ratios (ratio of low-energy mAs to highenergy mAs settings) ranging from 1 to 4. The cross-scatter correction algorithm
uses raw-data based on the object size estimations and look-up tables generated
by measurements of tissue-equivalent reference phantoms with varying size and
tube voltage. We evaluated the image quality of the CT images. For anthropomorphic phantoms, material density images for water and calcium with and without the
cross-scatter correction have been compared using two separate single source
scans as a reference.
Results: The distribution of cross-scatter intensity and corresponding artefacts
depended on the phantom dimensions and on the mAs-ratios. Scans at an mAsratio of 1 did not yield meaningful results. An mAs-ratio of 4 led to images with an
average deviation of water and calcium density values of up to 100% for a 30 x
40 cm² thorax phantom. Cross-scatter correction decreased the error down typically
to 25 and 15% for mAs-ratios of 1 and 4, respectively.
Conclusion: Cross-scatter may cause substantial artefacts and errors in the calculation of material-selective images, but can be corrected to a large degree.
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Scientific Sessions
B-402
14:09
Usefulness of 64-slice MDCT angiography for evaluating aortopulmonary
collateral arteries with complex pulmonary stenosis or atresia in children
Y. Peng, J. Li; Beijing/CN (ppengyun@yahoo.com)
Purpose: To evaluate the aortopulmonary collateral (APC) arteries with complex
pulmonary stenosis or atresia in children with 64-slice CT angiography (CTA).
Methods and Materials: A total of 28 children (16 boys, age 28 days to 8 years)
with pulmonary stenosis or atresia underwent 64-slice CT angiography. Diagnoses
included tetralogy of Fallot (TOF) with pulmonary atresia (n = 6) or pulmonary
stenosis (n = 4), post-Fontan palliation (n = 4), PA-VSD (n = 6), right pulmonary
artery absence (n = 3) and other complex congenital heart diseases (n = 5). Two
independent radiologists analyzed the numbers, origins, courses and the diameters
of APC arteries and the lung areas they supply. The results are compared with those
of cardiac catheterization (n = 15) using Bland-Altman analysis.
Results: CTA found 68 APC arteries, and 64 were confirmed by either surgical
procedure or catheterization. Four additional APCs were diagnosed by CTA, but not
by surgical procedure (n = 2) or catheterization (n = 2). CTA had a 100% sensibility and specificity for the diagnosis of main (n = 9) and branch pulmonary artery
stenosis or hypoplasia (n=21), as well as absent (n = 3) or discontinuous (n = 2)
branch PAs. Major APC arteries supplied the pulmonary circulation wholly in ten
patients. The CT measurements showed excellent inter-observer and intra-observer
reliability with coefficients of 0.91and 0.93, respectively. There were good correlation in diameter measurements between CT and catheterization with correlation
coefficient of r = 0.816.
Conclusion: CT angiography is an accurate, noninvasive alternative to surgical
procedure or catheterization for evaluating the characteristics of aortopulmonary
collateral arteries in children with complex pulmonary stenosis or atresia.
B-403
14:18
Sixty-four-row MDCT in neonates with complex congenital heart disease:
Preliminary experience
M. Ulla, J.L. Savluk, E. Levy, M. Vazquez-Durand, J. Makarovsky,
R. Garcia-Mónaco; Buenos Aires/AR (marina.ulla@hospitalitaliano.org.ar)
Purpose:To evaluate the clinical feasibility of 64-row MDCT in replacing diagnostic
cardiac catheterization (CC) in a consecutive series of neonates (less than 30 days
old) with complex congenital heart disease. To demonstrate the utility of 64-row
MDCT for anatomical delineation and pre-surgical evaluation.
Methods and Materials: Over a 1-year period, nine neonates (mean age = 7 days)
with complex congenital heart disease (more than one separate cardiovascular
anomaly) were prospectively scanned. In these patients, the diagnostic confidence
of echocardiography was low. A 64-row CT scan was performed in each neonate
with intravenous injection of diluted non-ionic iodinated contrast medium (2 ml/kg)
and injected with dual syringe injection. A multidisciplinary congenital heart disease
team evaluated the images and decided if diagnostic CC was necessary before
surgery. The mean scanning time was 5 seconds and the mean radiation dose
1.7 mSv. The diagnostic accuracy of 64-row MDCT was compared with surgical
findings and final clinical diagnosis.
Results: No diagnostic CC was needed in any neonate prior to the surgery. In
all cases, cardiovascular anatomy and relationship between adjacent structures
could be accurately assessed for the presurgical evaluation. Sedation times were
minimized (average 10 minutes), reducing potential complications in this population in comparison with CC.
Conclusion: In this preliminary series, 64-MDCT showed clinical feasibility of
replacing diagnostic CC in complex congenital heart disease of neonates. It proved
to be useful in cardiovascular anatomy delineation and achieved diagnosis in a
quick and non-invasive way. Further studies must be performed to validate this
experience.
B-404
14:27
Usefulness of the ECG-gated dual source CT for evaluating the
configuration of the coronary arteries in patients with congenital heart
disease
M. Nakagawa, M. Hara, K. Sakurai, Y. Ozawa, T. Kawai, S. Yuta; Nagoya/JP
(lmloltlolol@gmail.com)
Purpose: To evaluate how precisely ECG-gated DSCT can depict the configuration
of the coronary arteries (CAs) in children with congenital heart disease (CHD).
Methods and Materials: Between August 2006 and August 2008, 31 patients with
CHD (aged 1 day to 9 years, median age 11 months; body weight 2.3-17.0 kg,
median 6.7 kg) were examined using DSCT (SOMATOM Definition; Siemens) with
ECG gating and without breath holding. Mean heart rates were between 80 and
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150 bpm (median 124). The parameters of DSCT scan were 80-200 mAs, 120 kV,
0.75 mm slice thickness, 50% overlap and the time resolution was 83 msec. Nonionic contrast medium (300 mgI/mL, 2 mL/kg) was administrated using a power
injector. The degree of visualization of the CAs was graded as follows: grade 0, no
CAs were depicted at all; grade 1, only origins of the CAs were depicted; grade 2,
useful for diagnosing the abnormality of the CAs with mild motion artifacts; grade
3, excellent for diagnosing the abnormality of the CAs. The degree of visualization
was determined by consensus of two radiologists.
Results: Of the 31 patients with CHD, visual evaluation of the CAs was graded as
0 in 3 (10%), 1 in 5 (16%), 2 in 9 (29%) and 3 in 14 (45%) cases. All patients with
grade 0 or 1 visualization were younger than 2 months.
Conclusion: We suggest that DSCT with ECG gating is a useful technique for
evaluating the coronary artery of patients with various CHD older than 2 months.
B-405
14:36
Value of MDCT volume-rendered images in evaluation of children with
persistent respiratory symptoms due to vascular ring anomalies
Y. Peng, J. Li; Beijing/CN (ppengyun@yahoo.com)
Purpose: To investigate the usefulness of MDCT volume-rendered (VR) images
in evaluating the relationship between cardiovascular structures and the airway in
children with persistent respiratory symptoms duo to vascular rings.
Methods and Materials: We retrospectively reviewed the MDCT VR images of 26
children (20 boys, ages 4 days to 4 years) with suspected vascular ring contributing
to persistent respiratory symptoms. The VR views of cardiovascular structures and
the ‘transparent’ VR view of airways were reconstructed and composed to show
their relationship.
Results: The morphology and topography of the vascular anomalies and their
relation to adjacent tracheal ompression structures were assessed accurately by
the composite VR images, and imaging findings correlated well with intra-operative
findings and clinical diagnosis. Vascular rings were confirmed and included cases
of five complete and three incomplete double aortic arch; three right arch left
ligamentum; two innominate artery compression; threee (two) aberrant right (left)
subclavian artery; eight pulmonary artery sling. Stenoses were seen in the trachea
of 14 patients and isolated main bronchus obstruction was present in 3 patients.
Eight patients had compression of trachea, tracheal carinal and a main bronchus;
five of them had secondary long-segment tracheomalacia. Associated cardiac
anomalies and trachobranchus malformation were present in 31% (8/26) and 23%
(6/26) of the patients, respectively.
Conclusion: Composite MDCT VR images are reliable for demonstrating the
morphology and topography of vascular anomalies in relation to adjacent tracheobronchial tree compression structures in children with vascular rings, and can
provide more accurate evaluation for operation and anesthesia.
B-406
14:45
Mid-term follow-up after arterial switch operation for complete
transposition of the great arteries
S. Ley1, J. Ley-Zaporozhan1, M. Gorenflo1, T. Loukanov1, C. Sebening1, S. Hagl1,
H.E. Ulmer1, H.-U. Kauczor1, R. Arnold2; 1Heidelberg/DE, 2Freiburg/DE (ley@gmx.de)
Purpose: Transposition of the great arteries has to be surgically corrected by an
arterial switch operation. This complex surgical procedure has the potential for
significant short- and long-term complications like dilation of the neo-aortic root,
coronary and pulmonary artery (PA) stenosis. The aim was to determine a suitable
follow-up algorithm for mid-term follow-up.
Methods and Materials: 26 patients (mean age 10p2 years) were examined using
echocardiography, ECG-gated CTA and functional MRI (flow and cine measurements, pulmonary perfusion).
Results: CTA was capable of visualizing coronary arteries in all cases. Coronary
stenosis did not occur. Echocardiography failed to visualize the coronary arteries
in 81%. CTA showed that 41% of the PAs had moderate stenosis (25-50% lumen
reduction) and 10% had severe stenosis ( 50%). Visualization of pulmonary
arteries was not possible by echocardiography in 55%. No correlation between
MR-perfusion abnormalities and PA stenosis was found. In echocardiography, 4
patients showed a mild stenosis of the main PA (mean pressure gradient 34 mmHg)
while MRI found an increased velocity, suggestive for a stenosis, in 9 patients. 10
patients showed a neo-aortic root dilatation. In echocardiography, 8 patients had
mild, 4 had moderate aortic valve insufficiency. Aortic valve insufficiency was too
small to be quantified by MRI.
Conclusion: Stenosis of the PA was seen in a significant number of patients and
the leading complication after surgery. Echocardiography should be recommended
for the assessment of cardiac function, CTA for morphology of coronary arteries and
PA. The value of MRI for assessment of functional parameters is limited.
Scientific Sessions
B-407
14:54
Contrast-enhanced cardiac magnetic resonance imaging in children and
adolescents with clinically suspected myocarditis
D. Honnef, H.H. Hövels-Gürich, D. Gkalpakiotis, H. Kühl, M. Neizel, N. Krämer,
C.A. Schwartz, R.W. Günther, G.A. Krombach; Aachen/DE
(honnef@rad.rwth-aachen.de)
B-408
15:03
Comparative evaluation of chest radiography, low field MRI, the
Shwachman-Kulczycki score and pulmonary function tests in patients with
cystic fibrosis
A. Anjorin1, H. Schmidt2, H.-G. Posselt2, T.J. Vogl2, N. Abolmaali3; 1Basle/CH,
2
Frankfurt a. Main/DE, 3Dresden/DE (funmi.anjorin@gmail.com)
Purpose: To evaluate comparability of Chrispin-Norman-Scores (CN) in patients
with cystic fibrosis (CF) determined with conventional chest radiography (CXR)
and fast low-field MR-imaging (MR) of the lung parenchyma.
Methods and Materials: 73 patients (age 7-32 years, median 14) with CF received
their annual CXR and additional MR at 0.2 T (Magnetom Open Viva, Siemens).
Thorax imaging using the breath-hold CISS-sequences (TR/TE=6.17/2.97 ms,
SL=20 mm). In consensus reading, two pediatric radiologists with expertise in CF
analyzed CXR and MR using the CN-Scoring system.
Results: The meanpstandard deviation CN-score from MR was 12.0p4.5 with
a higher score than CXR in 23 patients (31.5%). The CN-score from CXR was
12.1p4.7 with a higher score than MR in 25 patients (34.3%). The difference
between the two scores was 0.12 and was not significant. There was a significant
correlation between both scores for all matched pairs (p 0.05, r=0.97). CXR and
MR-CN-scores correlated better with the measured FEV1 (p 0.001, r=- 0.65) und
(p 0.001, r=-0.65), respectively, than with FVC (p 0.001, r=-0.46) and (p 0.001,
r=-0.47). Both scores correlated to some degree with the Schwachman-Kulczycki
scores (p 0.001, r=-0.52 for CXR and r=-0.53 for MR).
Conclusion: CN-scoring of CF is possible with fast low-field MR. Since scoring
differences between CXR and MR are not significant, further research is strongly
suggested to reduce radiation exposure in patients with CF in long term follow-up,
especially in children with minor pulmonary involvement. In these cases the correlation of the clinical scores are poor, whereas the correlation of the imaging
scores are high.
B-409
15:12
Assessment of asymptomatic cystic fibrosis patients with normal lung
function tests, but chronic pseudomonas colonisation, using low-dose HRCT
O.J. O’Connor, K. O’Regan, S. McSweeney, M. Vandeleur, A. McGarigle,
M. O’Neill, M. Ni Chronin, M. Maher; Cork/IE (owen.oconnor@mailp.hse.ie)
Purpose: In cystic fibrosis (CF), pulmonary function tests (PFTs) and conventional
radiography (CR) are used to monitor disease. HRCT surpasses CR in detecting
mucous plugging, which precedes pseudomonas colonization and bronchiectasis,
often prior to PFT disturbance. Radiation doses are of particular concern in CF pa-
B-410
15:21
Lung development in congenital diaphragmatic hernia: Is the contralateral
lung normal?
C. Balassy, G. Kasprian, P.C. Brugger, B. Csapo, C.J. Herold, D. Prayer; Vienna/AT
(csilla.balassy@meduniwien.ac.at)
Purpose: CDH is associated with severe hypoplasia of the ipsilateral lung. The
purpose of this study is to assess the developmental changes of the apparently not
affected contralateral lung, using signal intensity ratios (SIR) and lung volumes.
Methods and Materials: A total of 16 fetuses (22-27 weeks of gestation) were examined with a 1.5 T unit. Mean SIs for lungs and liver were assessed on T1-weighted
and T2-weighted sequences, and then the lung/liver signal intensity ratios (LLSIR)
were calculated. These parameters, together with lung volumes, were compared
to an age-matched control group of 115 fetuses using t-test and U-test. Further,
SIRs and lung volumes were correlated with neonatal outcomes.
Results: Mean SIs of the lungs and LLSIRs in fetuses with CDH were significantly higher in both lungs on T1-weighted images, compared to the normal group
(P 0.001 and P = 0.029, respectively). On T2w imaging, mean lung SIs, but not
the LLSIR, were increased in both lungs in CDH, compared to the age-matched
controls (P 0.001). Total lung volumes were significantly smaller in the CDH group
than in the controls (P 0.001). The outcomes correlated significantly with total
lung volumes, but not with signal intensity changes in the lungs.
Conclusion: The significantly greater increase of lung SIs and LLSIR on T1w imaging in CDH can be explained by the relatively higher proportion of lung parenchyma
also in the contralateral lungs, compared to normal fetuses. The SI increase on
T2-weighted images is presumably caused by the accumulation of concentrated
alveolar fluid with elevated protein content in both lungs.
14:00 - 15:30
Room L/M
Vascular
SS 715
Therapy evaluation
Moderators:
A.L.J. Bojanovic; Nis/RS
J. Kettenbach; Vienna/AT
B-411
14:00
Dual-source CT in abdominal aortic aneurysm treated with endovascular
repair: Is dual energy imaging effective for endoleak detection?
P. Stolzmann1, T. Frauenfelder1, T. Pfammatter1, H. Scheffel1, M. Lachat1,
B. Schmidt2, B. Marincek1, H. Alkadhi1, T. Schertler1; 1Zurich/CH, 2Forchheim/DE
(paul.stolzmann@usz.ch)
Purpose: To investigate the diagnostic accuracy of dual energy dual source
computed tomography (DSCT) for the detection of endoleaks after endovascular
repair (EVR).
Methods and Materials: After EVR, 118 patients (21 females, 74p9 years)
underwent follow-up DSCT including non-enhanced, arterial, and delayed-phase
acquisitions. The delayed-phase data was acquired using the dual energy tech-
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Purpose: Late enhancement in myocarditis is well known in adults, but so far not
systematically assessed in children and adolescents. Consequently, the aim of our
study was to evaluate contrast-enhanced MRI in children and adolescents with
clinically suspected myocarditis.
Methods and Material: Between 2003 and 2008, 22 patients (5-24 years, mean
16.5 years; 17 male) with clinically suspected myocarditis due to clinical presentation
were examined on a 1.5 T MRI scanner with a synergy cardiac coil. The following
ECG-triggered sequences were evaluated: cine-balanced FFE; T2-TSE-STIR and
T1w-GRE with inversion pulse after contrast media application. We assessed wall
motion abnormalities, edema, late enhancement and pericardial effusion.
Results: Abnormalities on delayed contrast-enhanced MRI were found in 12/22
patients. Late enhancement was mainly midwall/subepicardial (n = 11) and less
frequently transmural (n = 1). Eleven patients had corresponding edema. In one
patient, T2-TSE-STIR was not available. Using the 17-segment model, 6.3 p 3.0
segments were involved per patient. The lateral left ventricular wall was affected
with 52.7% (septal 19.4%, anterior 18.1%, inferior 9.7%) of 72 enhancing segments.
The distribution of the left lateral ventricular wall was as follows: basal 47.4%, midcavity 36.8% and apical 15.7%. The inferolateral basis was most often involved
(10/72). Pericardial effusion was found in eight patients. Wall motion abnormalities
were assessed in five patients.
Conclusion: In our group of patients, contrast-enhanced MRI reliably demonstrated
the presence of myocarditis. In children and adolescents with clinically suspected
myocarditis, contrast-enhanced MRI can demonstrate the myocardial extent of
inflammation, wall movement abnormalities as well as concomitant pericardial
effusion.
tients (young patient, chronic, progressive disease). This study aimed to assess the
performance of low-dose HRCT in place of CR in CF patients with normal PFTs.
Methods and Materials: Following ethical approval, eight CF and five non-CF
patients underwent low-dose HRCT examinations. Six 1 mm slices were acquired at
120 kV, 30-50 mAs and 0.5 sec rotation time. The Bhalla HRCT scoring system was
used to assess disease severity. Image quality and noise were analysed subjectively
and objectively. Effective radiation doses were calculated for each HRCT.
Results: Disease severity was mild in the CF group (mean age: 14 yrs) with an
average Bhalla score of 7.0/25 (range 1-13). Of eight CF patients, seven had mild
bronchiectasis in more than nine segments. Non-CF patients (mean age: 13 yrs)
had minor parenchymal and airway changes with a significantly lower (P = 0.01)
average Bhalla score (0.2/25). Image quality was highly acceptable with an average
attenuation value standard deviation of 16 HU. The average effective dose was 0.17
mSv per HRCT for both groups.
Conclusion: Despite normal PFTs, a large proportion of CF patients had bronchiectasis and consolidation. This study demonstrates that low-dose HRCT can
detect important findings at effective doses comparable with CR (PA and lat),
with acceptable image quality. Thus, low-dose HRCT can potentially improve the
management of CF patients and selected subgroups of non-CF patients with
pulmonary symptoms.
Scientific Sessions
nique enabling the reconstruction of virtual non-enhanced images. Two blinded and
independent readers evaluated the data for the presence or absence of endoleaks
in three reading sessions: standard non-enhanced, arterial, and delayed-phase
(session A); virtual non-enhanced, arterial, and delayed-phase (session B); virtual
non-enhanced and delayed-phase (session C). Sensitivity, specificity, negative
(NPV) and positive predictive value (PPV) were calculated with session A as the
reference standard. Radiation dose parameters were estimated.
Results: Session A revealed 52 endoleaks in 118 patients (44%). The diagnostic
accuracy of reading sessions B and C were identical; sensitivity, specificity, NPV,
and PPV were 100, 97, 100, and 96%. The accuracy of sessions B and C were
not significantly different when compared to session A (P=.50). The effective dose
of protocol C was significantly (P .001) lower than that of a standard triple-phase
protocol (mean difference: 61%) and to that of a protocol including a standard
non-enhanced and a delayed phase (mean difference: 41%).
Conclusion: A single dual energy DSCT scan in the delayed-phase allows for the
accurate diagnosis of endoleaks after EVR of abdominal aortic aneurysms and
reduces the radiation exposure by omitting non-enhanced acquisitions by virtual
non-enhanced images.
B-412
14:09
Low-dose multidetector-row CT-angiography of abdominal aortic aneurysm
treated with endovascular repair (EVAR): A preliminary experience
R. Iezzi, A. Giammarino, D. Giancristofaro, D. Gabrielli, A. Cotroneo, M. Storto;
Chieti/IT (r.iezzi@rad.unich.it)
Purpose: To define the real influence of radiation dose on diagnostic accuracy of
CT scans in the follow-up of patients who underwent EVAR.
Methods and Materials: 30 consecutive adult patients (29 M, 1 F; mean age: 76.7p6
years; age range: 70-87 years) who had to be undergone 1- or 6-month follow-up
MDCT of the abdominal aorta as part of routine post-EVAR surveillance (mean
follow-up 8.9 months) were prospectively enrolled in our study. Two consecutive CT
scans were considered: at I° control CT exams were acquired using the standard
acquisition protocol (130 mAs/120 kV) whereas at II° control a low-dose scanning
technique (100 mAs/80 kV) was used. Axial and 3D-images were independently
evaluated by two blinded radiologists quantitatively (maximum arterial enhancement,
contrast-to-noise (C/N) rates), and qualitatively (technical adequacy, image quality,
and image noise). Quantitative and qualitative results were statistically compared.
Dose reduction was also evaluated.
Results: No statistically significant differences were found between the two protocols in terms of CNR (14.22p7.1 vs 11.44p7.8; p=0.17). The subjective qualitative
assessment of quality performed on axial images revealed statistically higher values
for the standard protocol rather than low-dose protocol in all segments evaluated
(p 0.001). On the other hand, no statistically significant differences were found
between the two groups in terms of subjective qualitative assessment of quality
performed on 3D images. An overall dose reduction as high as 74% was observed
for low-dose protocol.
Conclusion: In the post-EVAR CTA follow-up, it could be possible to reduce X-ray
exposure acquisition dose with no loss in image quality.
B-413
14:18
Dynamic CT-angiography in the diagnosis of aortic dissection and
endoleaks after endovascular repair of aortic aneurysms
W.H. Sommer, A. Graser, A. Helck, D.-A. Clevert, K. Nikolaou, M.F. Reiser,
T.R.C. Johnson, C.R. Becker; Munich/DE
(wieland.sommer@med.uni-muenchen.de)
Purpose: To assess the diagnostic accuracy of time-resolved CT-angiography
(TR-CTA) in aortic pathologies, in particular aortic dissection and endoleaks, after
endovascular repair.
Methods and Materials: Thirty-one patients with suspected endoleak or dissection
underwent TR-CTA of the aorta using a 128-slice CT-scanner with continuous bidirectional table-movement for time-resolved imaging. 12 phases covering the aortic
stent/dissection were acquired (acquisition time: 2.5 s per phase, 30 s total; scan
range: 27 cm; Ultravist 370, BayerSchering). Tube potential and current were lowered
to 80 kV and 120 mAs, in order to decrease radiation exposure. Timepoints of initial
and maximum-contrast enhancement were determined for: (a) true and false lumen
in patients with dissection and (b) for endoleak and the stent-lumen in patients with
endoleaks. The effective radiation exposure for TR-CTA was calculated.
Results: Seven aortic dissections and 9 endoleaks were observed. In patients
with dissection, maximum contrast enhancement occurred earlier in the true than
in the false lumen (17.8 vs. 20.7 s; p 0.01). In patients with endoleaks, inital
and maximum contrast-enhancement were significantly delayed in the endoleak
as compared to the stent-lumen (initial-enhancement, 4.7 vs. 9.4 s; p 0.01;
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maximum-enhancement, 15.0 vs 20.0 s; p 0.01). Mean effective radiation exposure was 14.6 mSv.
Conclusion: The current TR-CTA-protocol of the aorta is a promising new application to differentiate true and false lumen in aortic dissection and to assess dynamic
information of blood flow in patients with endoleak. This additional information is
important for the management of those pathologies and may be obtained with
comparable dose as compared to a standard two- or three-phase CTA-protocol.
B-414
14:27
Non-contrast volumetric CT for follow-up of endovascular abdominal aortic
aneurysm repair
T.A. Bley, P. Chase, K. Shinki, S. Reeder, C. Francois, G. Teferra, T. Grist,
M. Pozniak; Madison, WI/US (tbley@uwhealth.org)
Purpose: To evaluate the clinical utility of volumetric analysis of non-contrast CT as
the sole method to follow-up endovascular abdominal aortic repair and to identify
presence of clinically significant endoleaks.
Methods and Materials: The study had institutional review board approval. Retrospective image review was performed in a HIPPA compliant manner on 230 CT
studies from 70 patients (11 female and 59 male, mean age 74 years) who underwent endovascular abdominal aortic aneurysm repair (EVAR). The scan protocol
consisted of: 1) contrast enhanced CT angiography (CE-CTA) prior to endostent; 2)
CE-CTA at 0-3 months following repair to detect immediate complications; 3) non
contrast (NC) CT scans at 3, 6 and 12 months. For each follow-up visit, immediate
aortic volume analysis was performed. If the interval volumetric change was b 2%,
no further imaging was performed. If the volume increased by 2% on the NCCT
scan, a CE-CTA scan was immediately performed to identify suspect endoleak.
Results: Mean volume decrease was -3.2% (95% CI -4.7%, -1.9%) in intervals
without occurrence of a clinically relevant endoleak (n=183). Type 1 and 3 “high
pressure” endoleaks (n=10) showed a 10.0% (95% CI 5.0%, 18.2%) interval
volumetric increase. Type 2 “low pressure” endoleaks (n=37) showed a 5.4% (95%
CI 4.6%, 6.2%) interval volumetric increase. Endoleaks associated with minimal
aortic volume changes 2% were clinically not significant and did not require any
intervention in our patient population.
Conclusion: NCCT aortic aneurysm volumetric analysis can adequately screen
for the presence of clinically significant endoleaks.
B-415
14:36
Using engineering mathematical models and CT 4D imaging to understand
the hemodynamics after aortic prosthesis insertion
L.V. Forzenigo1, M. Domanin1, A. Veneziani2, L. Gabrielli1, C. Vergara1,
P. Biondetti1, S. Romagnoli1, A. Molinari1, L. Antiga1; 1Milan/IT, 2Atlanta, GA/US
(laura.v.f@libero.it)
Purpose: Mathematical models have an important role in industrial engineering
and an increasing role also in the biomedical field. A good example is the hemodynamic evaluation of patients after insertion of aortic prosthesis. Our goal was to
analyze the virtual haemodynamics of aortic flow after endoprosthesis insertion
and to optimize the design of the prosthesis related to: aortic flow pattern, heart
function, aneurysmal thrombus, endoleak and endotension.
Methods and Materials: Our experience concerns six patients who underwent
endoprosthesis insertion because of AAA. Each patient was studied before intervention with Doppler ultrasound and double source ECG-gated 64 rows CT
angiography (4D imaging). After aortic endoprosthesis insertion, these patients
had Doppler ultrasound and double source ECG-gated 64 rows CT follow-ups
at 1, 3, 6, 12 and 24 months. Because of ECG-gated acquisition (4D), images
were available for each phase of the R-R interval. CT DICOM data were sent to
Politecnico Engineering for 3D reconstruction of the anatomy and simulation of
aortic haemodynamics before and after prosthesis insertion; also the interaction
with the intra-aneurysmal thrombus was evaluated.
Results: Preliminary results show that after endoprosthesis insertion, there is an
increase of intra-aortic flow velocity, with a decrease of lateral pressure. The rigid
prosthesis interrupts the pressure wave originated with the cardiac pulsation, with
retrograde negative effects on the heart function.
Conclusion: Computed modelling of aortic flow haemodynamics can help to
optimize the prosthesis design, tailoring it to each patient.
Scientific Sessions
B-416
14:45
Endoleak detection with CT angiography in an aortic aneurysm phantom:
Effect of tube energy and physical properties of endoleaks
Z. Szucs-Farkas, M. Semadeni, S. Bensler, M.A. Patak, G. von Allmen, P. Vock,
T. Schindera; Berne/CH (zsolt.szuecs@insel.ch)
B-417
14:54
Comparing true and virtual non-contrast phases of dual source computed
tomography in the diagnosis of patients with endovascular repair of aortic
aneurysms
W.H. Sommer, A. Graser, D.-A. Clevert, K. Nikolaou, M.F. Reiser, C.R. Becker,
T.R.C. Johnson; Munich/DE (wieland.sommer@med.uni-muenchen.de)
Purpose: For patients with status post endovascular repair of aortic aneurysms,
unenhanced CT scans are necessary for differentiation of calcifying thrombus from
contrast-agent, i.e., an endoleak. This study determined whether virtual non-contrast
(VNC) images derived from dual energy CT (DECT) examinations can replace true
non-contrast (TNC) acquisitions.
Methods and Materials: 62 patients with aortic stentgrafts underwent dual-sourceCT scan (Siemens SOMATOM-Definition) including single-energy non-contrast
and dual energy scan in the venous contrast phase (Ultravist 370, BayerSchering). On a five point scale, two experienced radiologists evaluated image quality
(for VNC and TNC), acceptance level and subtraction of calcification (for VNC).
Presence of endoleaks was assessed based on contrast enhanced images and
either (1) VNC or (2) TNC images. Dose-length products derived from the scan
protocol were used to estimate effective doses for both non-contrast and contrastenhanced acquisitions. Percent differences for a single-phase and a dual-phase
protocol were calculated.
Results: Nineteen endoleaks were detected among the patients. Mean image
quality was rated “good” for VNC (1.92p0.96) and "excellent" for TNC (1.17p0.38;
p 0.05). In 62 of 65 patients (95.4%), VNC images were diagnostic. Subtraction
of calcification in VNC images was classified as none (56.9%), minimal (20.0%),
moderate (15.4%) or severe (7.7%). Mean effective dose was 9.37p0.33 and
9.21p0.27 mSv for unenhanced and DECT-scans, respectively. Dose-reduction
for a single phase protocol was 50%.
Conclusion: DECT allows reliable detection of endoleaks in patients with status
post endovascular repair of aortic aneurysms. In comparison to current examination
protocols, omission of a non-contrast phase will lead to a 50% dose-reduction.
B-418
15:03
Detection of endoleaks after endovascular repair of aortic abdominal
aneurysm: A new biphasic single-injection with single-acquisition MDCTangiography protocol
B.J. Gonçalves, A. Gil-Agostinho, M. Seco, A. Canelas, V. Carvalheiro,
F. Caseiro-Alves; Coimbra/PT (belarmino.goncalves@gmail.com)
Purpose: To evaluate the feasibility of a new MDCT protocol using biphasic enhanced single-acquisition for the detection of endoleaks after endovascular repair
(EVAR) of aortic aneurisms (AA). To compare the radiation dosages and imaging
findings of this new protocol with those from classic protocol using multiphase
acquisition.
B-419
15:12
Reproducibility of MR arteriography and flow to quantify therapeutic
macrovascular response in peripheral arterial disease
B. Versluis1, M. Van Eupen1, P.J. Nelemans1, E.V. Rouwet2, J.A.W. Teijink2,
J.E. Wildberger1, W.H. Backes1, T. Leiner1; 1Maastricht/NL, 2Heerlen/NL
(bas.versluis@rad.unimaas.nl)
Purpose: Non-invasive imaging techniques are urgently needed to evaluate
therapeutic response in peripheral arterial disease (PAD) and to detect vascular
adaptations. The aim was to assess the reproducibility of MR arteriography to
quantify the number of arteries and the flow of conduit arteries.
Methods and Materials: Ten healthy volunteers and ten patients with proven PAD
(Fontaine stadium II) and collateral formation were prospectively imaged twice within
1 week. The subjects underwent 3D contrast-enhanced MR arteriography covering
the entire upper leg and subsequent phase-contrast flow waveform measurements
in the superficial femoral (SFA) and popliteal artery (PA). Two independent readers
determined the number of arteries bypassing on five transverse planes at 5 cm
distance. Inter- and intra-observer reproducibility was expressed by intra-class correlation coefficients (ICC) and repeatability coefficient (RC), where RC quantifies
the smallest detectable change.
Results: The number of arteries per slice was significantly higher in patients
(15.7 p 3.5) than in volunteers (12.9 p 2.5, P 0.01). Intra-observer reproducibility
(i.e. repeated acquisitions) of artery count showed high ICC (0.98), whereas the
inter-observer reproducibility was slightly lower (volunteers: 0.72, patients: 0.85).
RC in patients was 1.1.
Peak systolic flow was significantly lower in patients (SFA, 7.7 p 3.6; PA,
4.5 p 2.8 mL/s) compared to volunteers (SFA, 15.6 p 2.5; PA, 9.6 p 2.5 mL/s,
P 0.01). ICC of flow was 0.90 in patients and 0.93 in volunteers for both the SFA
and PA. RC in patients was 1.7 mL/s (SFA) and 1.9 mL/s (PA).
Conclusion: MR-derived angiographic artery count and flow quantification provide
reproducible measurements to evaluate morphological and functional adaptations
of macrovasculature in PAD.
B-420
15:21
Evaluation of vessel size imaging to detect antiangiogenic therapy
response
S. Zwick1, R. Strecker2, V. Kiselev3, P. Gall3, M. Palmowski4, W. Semmler1,
F. Kiessling4; 1Heidelberg/DE, 2Erlangen/DE, 3Freiburg/DE, 4Aachen/DE
(s.zwick@dkfz.de)
Purpose: To assess vascular remodelling in tumors during antiangiogenic therapy
with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and vessel size imaging and to evaluate the vessel size index (VSI) as a novel biomarker
of therapy response.
Methods and Materials: In total 12 tumor-bearing nude mice (6 controls, 6 therapies) were investigated with DCE-MRI and vessel size imaging before and after 4
days of multitargeted tyrosine kinase inhibitor treatment (SU11248). MRI measurements were performed on a clinical 1.5 T whole-body MRI system. DCE-MRI data
were analysed applying a two-compartment model (Brix), calculating the parameters
Amplitude and kep. Afterwards the tumors were investigated by histology.
Results: The parameter Amplitude decreased significantly over time in treated
tumors (0.20 p 0.09 a.u). compared to untreated ones (0.02 p 0.08 a.u)., whereas
kep showed no significant change in treated (0.28 p 0.41 1/min) over untreated
(-0.05 p 0.25 1/min) tumors. Also the VSI was capable to mirror antiangiogenic
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Purpose: To analyze detection of endoleaks with low tube voltage CT angiography (CTA).
Methods and Materials: A cylindrical plastic phantom mimicking an aortic aneurysm containing a stent graft and 36 simulated endoleaks of various diameter (2,
4, and 6 mm) and distance from the graft (0, 5 and 10 mm) was placed into a water
container corresponding average sized patient weighing ca. 72-85 kg. CT scanning
was done at 80, 100 and 120 kVp and volume CT dose indices (CTDIvol) were noted.
Three radiologists independently analyzed CT images for endoleak localization with
diagnostic confidence and image quality. Analysis of variance was used to compare
results and to find parameters with effect on endoleak detection.
Results: All 6 mm endoleaks were correctly identified at all tube energies. Observers detected more 4 mm leaks at 100 kVp compared to 80 kVp (p= 0.006). The
overall sensitivity was only 2.8% for the 2 mm endoleaks. The diagnostic confidence
increased parallel with tube energy (p= 0.004). CTDIvol was by 27% lower at 80 kVp
compared to 100 kVp. Diameter and position of endoleaks and tube voltage had all
a significant effect on the number of detected leaks (p 0.0001).
Conclusion: Reduced radiation exposure is achievable with CTA using 80 kVp
in average sized patients with no risk of missing endoleaks measuring 6 mm or
larger. 100 kVp protocols are advisable if the threshold for endoleaks demanding
therapy is defined at 4 mm.
Methods and Materials: A total of 30 patients (25 men, 5 women) with abdominal
AA submitted to EVAR were referred to MDCT evaluation. A new MDCT-angiography
protocol was set up. First an unenhanced scan was performed. Enhanced scan
included an initial injection of 50 mL of iodine contrast (without any delay and at
a rate of 4 mL/min). After a delay of 60 sec another injection of more 50 mL using
bolus tracking was given and followed by a 30 mL saline flush (3 mL/sec). Imaging findings were compared with the former MDCT evaluation (6 to 12 months of
interval between the two exams) that used the classic protocol with 2 enhancement
phases (arterial and venous). Dose reports were also compared.
Results: Within the classic protocol evaluation, endoleaks were diagnosed with
the arterial phase in 20 (66%) and with the venous phase in 30 (100%) patients,
respectively. Within this new protocol all the previously detected endoleaks were
diagnosed in all patients (n = 30). This protocol also contributed to a mean of 34.3%
reduction of the effective dose delivered.
Conclusion: A biphasic single-injection with single acquisition protocol works
as a mixed venous-delayed arterial phase enabling detection of early or delayed
endoleaks. Scan time and radiation exposure can also be decreased by eliminating
a second enhanced acquisition.
Scientific Sessions
therapy response showing significant higher changes in treated (7.6 p 7.7 µm)
than in untreated tumors (-3.9 p 5.4 µm) over time. Histological analysis proved
the success of the antiangiogenic therapy and showed lower mean vessel area
fractions in treated tumors, and an increase of the mean vessel size in treated
compared to untreated tumors.
Conclusion: Results of both methods are in excellent agreement with histology.
DCE-MRI and vessel size imaging provide reliable and supplementing biomarkers
of antiangiogenic therapy response.
14:00 - 15:30
Room N/O
Neuro
SS 711
Stroke
Moderators:
F. Pizzini; Verona/IT
J. Walecki; Warsaw/PL
B-421
14:00
Combined use of arterial spin labelling and susceptibility-weighted
imaging in acute stroke helps predict hemorrhagic transformation
S. Altrichter1, R. Sztajzel1, L. Sekoranja1, M. Viallon1, F. Lazeyras1, M. Vargas1,
J. Delavelle1, A. Federspiel2, K.-O. Løvblad1; 1Geneva/CH, 2Berne/CH
(karl-olof.lovblad@hcuge.ch)
Purpose: We wanted to determine if the combined use of arterial spin labelling
(ASL) and susceptibility-weighted imaging (SWI) could improve the detection of
hemorrhage in acute stroke.
Methods and Materials: We prospectively examined 31 patients (aged 50-89 years)
with acute stroke. Imaging was performed between 1 day and 2 weeks on a 3.0 T
Magnetom Trio (Siemens; Erlangen, Germany). ASL was performed with a PASL
sequence, using a QUIPSII perfusion mode, RelCBF maps for ASL were calculated
in-line by the MRI scanner, and off-line for CEPWI using the Syngo Perfusion (MR)
software (Siemens Medical Solutions). SWI was performed using a 3D acquisition.
CEPWI was also acquired as well as DTI with a 30-direction scan.
Results: Acute ischemic lesions were seen on DWI in all cases, whereas hypoperfusion was observed in 29. There was a perfect match between ASL and CEPWI in 21
cases. Hypoperfusion was observed on ASL in ten cases and hyperperfusion in nine
cases. Hemorrhage or BBB breakdown were visible on SWI in seven cases. Early
SWI changes together with hypoperfusion were associated with the occurrence of
hemorrhage. Hyperperfusion on ASL was not associated with hemorrhage in the
absence and presence of changes on SWI.
Conclusion: The presence of hyperperfusion on ASL perfusion seems indicative
of reperfusion/collateral flow that is protective of hemorrhagic transformation. The
combination of hypoperfusion and changes on SWI seems on the other hand to
predict hemorrhage. Thus, combining these techniques in addition to standard
schemes, increases the power of MRI to predict tissular outcome in acute stroke
B-422
14:09
Detection of intracerebral hemorrhage with flat-detector CT compared to
multislice CT: Preliminary results in 44 cases
T. Struffert, T. Engelhorn, M. Doelken, P. Gölitz, W. Kalender, O. Ganslandt,
A. Doerfler; Erlangen/DE (tobias.struffert@uk-erlangen.de)
Purpose: The aim of the study was to test the reliability of intracerebral hemorrhage
(ICH) detection with flat-detector computed tomography (FD-CT) as compared to
multislice CT (MSCT).
Methods and Materials: In this study, 44 patients with 45 ICH were included. All
patients were investigated with FD-CT and MSCT. As a control group, we included 16
patients without ICH. In each haematoma, we assessed volumetric data of the ICH and
counted the numbers of ICH positive slices. Using interobserver rating, we additionally
investigated the potential of FD-CT to serve as a diagnostic tool to detect ICH.
Results: In FD-CT, three haematomas were not detected because of motion and
beam hardening artifacts in the region close to the skull base. The r value for the
degree of interobserver agreement for the number of slices was 0.95 for MSCT
and 0.94 for FD-CT. Measurements of the area and the calculated volume of the
ICH showed high inter- and intraobserver agreement.
Conclusion: Our results indicate that FD-CT is a helpful tool in the daily emergency
management of ICH patients as detection of ICH was found to be nearly as reliable as in MSCT. Limitations of this technology are motion and beam hardening
artifacts that may mask small haematomas located in the posterior fossa or the
skull base.
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B-423
14:18
The role of 3D susceptibility-weighted imaging in the detection of cerebral
microbleeds in lacunar infarction patients
X. Hong, D. Wang; Nanjing/CN (hongxunning@hotmail.com)
Purpose: Lacunar infarcts are small strokes that lie in the deep noncortical parts
of the cerebral hemispheres and brain stem. Our purpose was to evaluate the role
of susceptibility-weighted imaging (SWI) in the detection of microbleeds in lacunar
infarction patients.
Methods and Materials: Using a Siemens 3.0 T MR unit, 254 cases showing
abnormal signal on T2 and FLAIR, consistent with lacunar infarct, were included
in this study. The MRI examination consisted of axial T1-weighted fl2d imaging,
axial T2-weighted fast-spin echo imaging, axial FLAIR fast-spin echo imaging and
3D susceptibility-weighted imaging.
Results: Of the 254 cases (male144, female 110, average age 65.5 years), SWI
showed evidence of microbleeds in 62 cases (male 51 and female 11), compared
to 15 (male 11 and female 4) with T1, T2 and FLAIR. Cerebral microbleeds were
detected in significantly more persons (P 0.01) with SWI (24.4%), compared with
conventional T2 and FLAIR imaging (5.9%). There were no cerebral hemorrhages
visualized on the conventional MRI sequence that were not detected on the SWI
sequence. Microbleeds were found in 35.4% of male patients and only in 10% of
female patients. Microbleeds were almost four times more frequent in elderly (= 60)
than in younger patients ( 60; 31.3 versus 8%, P 0.05).
Conclusion: The 3D SWI is more sensitive than the conventional MRI sequences
for the detection of cerebral microbleeds that may prove useful in the treatment of
lacunar infarction. Microbleeds are not rare in old patients. It is recommended as
part of MR study in the elderly or prior to anticoagulation treatment.
B-424
14:27
High-risk carotid artery plaques increase the risk of ischemic stroke in
asymptomatic individuals: A study from the Cardiovascular Health Study
J.F. Polak1, J.C. Nelson2, T.A. Manolio3, D. Lefkowitz4, D.H. O’Leary5;
1
Boston, MA/US, 2Seattle, WA/US, 3Bethesda, MD/US, 4Winston-Salem, NC/US,
5
Dorchester, MA/US (JPolak@tuftsmedicalcenter.org)
Purpose: It is believed that certain ultrasound characteristics of carotid artery
plaque are associated with an increased risk of stroke. We investigated this in
a longitudinal follow-up of asymptomatic members of the Cardiovascular Health
Study aged 65 years.
Methods and Materials: Clinical characteristics and cardiovascular risk factors
were acquired during a baseline clinic visit. Plaques were categorized as high risk
(HR) with a degree of stenosis 50% or heterogeneous-echolucent according to
the European consensus meeting or markedly irregular plaque surface, low risk for
absent plaques (LR) and moderate risk (MR) for all other plaques. Ultrasound findings were blindly interpreted from videotape without access to clinical information.
Stroke was ascertained in 12 years of follow-up by panel review of clinical records.
Cox proportional hazards models were use to evaluate the association between
plaque characteristics and the risk of ipsilateral ischemic stroke as determined by
blinded panel review.
Results: HR plaques were seen in 465 of 5425 individuals. The stroke rate was
significantly higher for HR 9.2% (43/465) and MR (6.1% 225/3704) compared to
LR (4.1% 51/1256) plaques. The risk of stroke remained higher for HR (154, 57,
312%) and MR (56, 17, 108%) compared to LR plaques after adjustment for age,
race, sex and major CHD risk factors.
Conclusion: Ultrasound appearance of carotid plaque can identify a subset of
asymptomatic older individuals with increased risk of stroke.
B-425
14:36
Assessment of the patency of the major dural venous sinuses with
standard CT angiography in the setting of intraparenchymal cerebral
hemorrhage
J.E. Delgado Almandoz, H.S. Su, P.W. Schaefer, S.R. Pomerantz, M.H. Lev,
J.M. Romero; Boston, MA/US (jdelgadoalmandoz@partners.org)
Purpose: To determine the frequency of adequate contrast opacification of the
dural venous sinuses during the initial CT angiogram (CTA) in patients presenting
with intraparenchymal hemorrhage (IPH), an essential factor in the exclusion of
dural sinus thrombosis (DST) as the IPH etiology.
Methods and Materials: We conducted a retrospective review of the initial CTAs
performed in 75 consecutive patients presenting to our Emergency Department
with IPH. Two neuroradiologists determined whether contrast opacification in each
of the major dural venous sinuses was adequate to exclude DST. Delayed scans, if
obtained, were also reviewed. CTAs were performed in a 64-slice CT scanner with
Scientific Sessions
Smart-Prep technique by scanning from C1 to the vertex following administration
of 65-80 mL of contrast material.
Results: In the first-pass CTA, adequate contrast opacification was achieved in
77% of the superior sagittal, 68% of the right transverse, 61% of the left transverse,
40% of the right sigmoid and 33% of the left sigmoid sinuses. Delayed scans were
obtained in 23 cases (31%, range 5-310 seconds after first-pass scan), 21 of which
demonstrated adequate contrast opacification in all the major dural sinuses (91%).
A diagnosis of DST was subsequently made in 4 patients (5%), none of which
demonstrated adequate contrast opacification in the affected dural venous sinus
during the first-pass or delayed scan (if obtained).
Conclusion: In the setting of an IPH, inadequate contrast opacification of a major
dural venous sinus during the first-pass CTA should prompt acquisition of a delayed
scan to exclude DST as the IPH etiology.
B-426
14:45
Stroke-CT: Initial experiences with whole brain perfusion-CT
D.F.B. Morhard, C. Wirth, M.F. Reiser, C.R. Becker; Munich/DE
B-427
14:54
Whole-brain 4D-CT in stroke patients: Our initial experience
J. Ferda1, H. Mírka1, T. Flohr2, B. Schmidt2, J. Baxa1, B. Kreuzberg1; 1Plzen/CZ,
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Forchheim/DE (ferda@fnplzen.cz)
Purpose: To assess the clinical value of dynamic whole-brain CT (4D-CT) in
patients with suspected stroke.
Methods and Materials: The prospectively collected data were evaluated in 25
patients (mean age 55.1 years; 14 males, 11 females) with suspected hemispheric
stroke. The adaptive multiphase spiral data acquisition covering the entire brain
volume, i.e. time-resolved scanning of a region larger than the detector width by
continuous periodic table movement, was performed in 25 cycles every 1.5 s performed after application of 30 ml of iodinated contrast material. The collimation of 20
x 1.2 mm was used. The 5 mm images were reconstructed to analyze whole-brain
perfusion and 1.5 mm images (0.7 mm increment) to create dynamic angiograms
(4D-CTA). The perfusion maps of the entire brain were calculated.
Results: No perfusion or circulation disorder was found in 12 patients, some perfusion deficit in 9 patients, circulation disorder without perfusion deficit in 3 patients
and brain tumor in 2 patients, respectively. The localization of the perfusion deficit
extended the conventional area of perfusion CT in six patients, including five in
whom additional information was obtained from whole-brain perfusion. Compared
to the static CTA, 4D-CTA enabled additional description of collateral circulation
or the cause of the perfusion deficit in four cases, three cases of pure circulation
disorders and in tumors. 4D-CTA combined with whole-brain perfusion offered
additional information in 48% of the patients
Conclusion: 4D-CT covering the entire brain improves the assessments of ischemia
including its extent, perfusion deficits and collateral circulation.
15:03
Quantitative imaging of spontaneous neuromagnetic activity for assessing
cerebral ischemia using sLORETA-qm
S. Sakamoto1, N. Tsuyuguchi1, Y. Terakawa1, H. Tanaka2, W. Ide3, I. Hashimoto3,
H. Kamada3, Y. Inoue1; 1Osaka/JP, 2Kanazawa/JP, 3Obihiro/JP
(s-sakamoto@med.osaka-cu.ac.jp)
Purpose: To image cerebral neural activity in the ischemic area, we proposed a
novel technique to analyze spontaneous neuromagnetic fields based on standardized low-resolution brain electromagnetic tomography modified for a quantifiable
method (sLORETA-qm).
Methods and Materials: Using a 160-channel whole-head-type magnetoencephalographic (MEG) system, cerebral magnetic fields were obtained from pre- and
postoperative conditions of 5 patients with unilateral internal carotid artery occlusive
disease and 16 age-matched healthy volunteers. For quantitative imaging, voxelbased time-averaged intensity of slow waves in 4 frequency bands (0.3-2, 2-4, 4-6
and 6-8 Hz) were obtained by the proposed technique based on sLORETA-qm.
Positron emission tomography with 15O gas inhalation (15O-PET) was also performed
in these patients to evaluate cerebral blood flow and metabolism.
Results: In all 5 patients, slow waves of every frequency band were distributed
in the area of cerebrovascular insufficiency confirmed by 15O-PET preoperatively.
In 4 patients, slow-wave intensities in theta bands (4-6 and 6-8 Hz) decreased
postoperatively along with improvements in cerebral blood flow and metabolism,
whereas delta bands (0.3-2 and 2-4 Hz) showed no significant differences between
pre- and postoperatively. One patient with deterioration of cerebral infarction after
surgery showed marked increases in slow-wave intensities in delta bands (0.3-2
and 2-4 Hz) postoperatively, with distribution close to the infarct region.
Conclusion: The proposed quantitative imaging of spontaneous neuromagnetic
fields enabled clear visualization of cerebral neural conditions in the ischemic area.
This technique may offer a novel, non-invasive method for identifying cerebral
ischemia.
B-429
15:12
Low-dose neurovascular HYPR-CT methods
H. Rowley, M. Supanich, K. Pulfer, G.-H. Chen; Madison, WI/US
Purpose: Radiation dose reduction and noise reduction for the same dose are
demonstrated for dynamic, contrast-enhanced neuro CT protocols using highly
constrained back projection (HYPR)-CT methods.
Methods and Materials: Raw CT projection data from 12 patients and 26 canine
scans, all with neurovascular defects, using a standard CT perfusion protocol were
saved and processed for retrospective reconstruction. Radiation dose reduction
was simulated via view-angle undersampling. Dose reduction factors of 10 were
simulated using one-tenth the acquired projection data along with the HYPR-CT
method to maintain waveform fidelity and noise characteristics of a fully sampled
series. The HYPR-CT method was implemented to produce standard 5 mm slicethickness perfusion maps and 64-slice dynamic CTAs at simulated dose reduction
factors up to 10. HYPR-CT methods were also used to improve image quality for
0.625 mm slice-thickness perfusion analysis at full dose.
Results: Correlation between ROIs from standard and HYPR-CT reconstructed perfusion maps greater than 0.9 have been demonstrated for up to a sixfold simulated
dose reduction with coefficients of variation consistent with scan-to-scan variations.
HYPR-CT dynamic CTAs show a squared difference of less than 0.05 from standard
reconstructions at a simulated dose reduction of 10 during contrast uptake for
vascular ROIs. Noise is reduced by a factor of 2.5 over standard reconstruction at
the same dose using HYPR CT methods for 64-slice perfusion analysis.
Conclusion: HYPR CT methods produce an immediate decrease in image noise
on existing platforms and offer a potential sixfold reduction in radiation dose for
contrast-enhanced acquisitions while maintaining image quality and physiological
information.
B-430
15:21
CT perfusion in predicting delayed cerebral ischemia after aneurysmal
subarachnoid hemorrhage
N. Khandelwal, P. Singh, S.H. Tirumani, A. Pathak, V. Gupta; Candigarh/IN
(khandelwaln@hotmail.com)
Purpose: Evaluation of role of CT Perfusion (CTP) in predicting delayed cerebral
ischaemia (DCI) after subarachnoid hemorrhage (SAH).
Methods and Materials: We prospectively studied the CTP parameters, noncontrast head CT (NCCT) and CT angiography (CTA) at admission in 30 patients
with aneurysmal SAH. All were followed for 1 week postoperatively by neurologic
assessment and serial NCCT for DCI. We analysed clinical and semiquantitative
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Saturday
Purpose: In standard stroke CT protocols, perfusion-CT (PCT) has a detector width-dependent scan range of 1-4 cm. Recently introduced toggling table
technique PCT offers the opportunity to cover ranges of the entire brain volume
(VPCT), and additional reconstructions provide time-resolved CTA (4D-CTA). The
purpose of our study was to evaluate the benefit of VPCT and 4D-CTA compared
to standard PCT and CTA.
Methods and Materials: A total of 25 patients were scanned with a 128-slice CT
scanner. Standard perfusion parameter maps were reconstructed for all data sets,
as well as 4D-CTA (64 slices à 1.5 mm, time resolution of 1.5-3 s) and standard
intracranial CTA reconstructions (slice thickness 1.0 mm). For evaluation, two different image samples were created: VPCT-group: perfusion parameter maps of the
whole scan range and 4D-CTA; standard group: 2 x 10 mm parameter maps at the
basal ganglia, similar to standard PCT and standard CTA. A consensus reading
was performed by two radiologists to evaluate the impact of VPCT and 4D-CTA
compared to the simulated standard group.
Results: In eight (32%) of these data sets, pathological brain perfusion was detected with VPCT. In four (50%), subsegmental infarctions superior to the basal
ganglia were not covered in the standard PCT group. In all patients with restricted
brain perfusion, pathological changes were found in 4D-CTA, while one vascular
pathology (13%) was not detected with standard CTA alone.
Conclusion: VPCT helps to detect infarctions in the more superior levels of the
brain compared to standard PCT. The 4D-CTA can provide additional information
about hemodynamics and relevant information in a small group of patients.
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CTP parameters between patients with and without DCI. Statistical analysis was
done using nonparametric tests (p-value 0.05).
Results: DCI was more common in females and in patients with low GCS at
presentation. Fisher Grading for SAH showed no significant association with
DCI. In 19 patients with DCI, average lowest rCBF and rCBV were 0.77 and
0.85. Average highest dTTP and dMTT were 1.20 and 1.35. The corresponding
values in 11 patients without DCI were 0.90, 0.91, 1.07 and 1.14 respectively.
With threshold values of 0.75, 0.80, 1.0 and 1.1 for CBF, CBF, MTT and TTP, the
sensitivities of dTTP and dMTT were 95% and 70%, and specificities were 30%
and 43% respectively for predicting DCI. rCBF and rCBV had sensitivity of 43%
and 40%, and specificity of 85% and 71% respectively. The relative risk was 1.875
for elevated dMTT ( 1.15).
Conclusion: CTP is easily available and can be combined with NCCT and CTA for
predicting DCI after SAH. TTP is a sensitive predictor of vasospasm and combination
of TTP and CBF has a better sensitivity/specificity than individual parameters.
14:00 - 15:30
Room P
Chest
SS 704
Airway imaging and functional data
Moderators:
N. Howarth; Chêne-Bougeries/CH
S. Ley; Heidelberg/DE
B-431
14:00
Radiologic-pathologic correlation: Accuracy of automatically assessed
bronchial wall-thickness
T. Achenbach1, O. Weinheimer1, C. Brochhausen1, D. Hollemann1, C. Stanger1,
C.P. Heussel2, C. Dueber1; 1Mainz/DE, 2Heidelberg/DE (achenbac@uni-mainz.de)
Purpose: Increase of airway-wall-thickness in MDCT is an important marker for
inflammatory bronchial changes e.g. in COPD patients. Automated measurements
have shown high accuracy in phantom studies if dedicated algorithms as the integralbased-method (IBM) are applied. Up to now, no exact radiologic-pathologic correlation of the same localization of an organic bronchus was published as morphology
preserving preparation techniques are crucial but difficult. The aim of this study was
to test the accuracy of our automated measurement method.
Methods and Materials: Immediately after euthanization, two porcine lungs were
excised by thoracotomy, intubated and submerged into a bath of liquid nitrogen
while inflated by a lung ventilator. The frozen and ventilated lungs were scanned
and appropriate levels were ink-marked by MDCT and its gantry-laser. Frozen
sections from bronchi of these levels were cut and stained by hematoxylin and
eosin. Medians of microscopically (CellB, Sof Imaging System GmbH) and MDCTassessed wall-thicknesses were compared.
Results: Airway morphology was well preserved after microtome cutting allowing
comparison of CT- and microscopic images. By the time of submission, the first
slice was correlated. Airway wall thickness was 0.62 mm assessed with MDCT and
the IBM (1.06 mm by standard full-width-at-half-maximum-technique) and 0.58 mm
with digital microscopic measurement.
Conclusion: Quick-freezing of inflated porcine lungs preserved bronchial morphology enabling direct comparison of CT-images and microscopic images of the
same localization. Hence, for the first time in a non-phantom setting, automated
wall-thickness assessment of a bronchus demonstrated high accuracy with a
tendency towards overestimation.
B-432
14:09
Assessment of lobar pulmonary perfusion in COPD patients: Preliminary
experience with dual energy CT angiography
V. Pansini, M. Rémy-Jardin, J.-B. Faivre, T. Perez, A. Duhamel, J. Rémy; Lille/FR
(mremy-jardin@chru-lille.fr)
Purpose: To assess pulmonary perfusion on a lobar level in COPD patients using
dual energy CT.
Methods and Materials: Thirty-eight smokers with a mean cigarette consumption
of 30 pack-years underwent a dual energy MDCT angiogram of the chest (Definition, Siemens) with a standard injection protocol. 3D-HRCT data (i.e., contiguous
1-mm thick averaged images from both tubes) were analyzed for detection and
quantification of emphysema using a commercially-available software (Pulmo 3D,
Siemens). Lung perfusion was analyzed at a lobar level on perfusion scans with
automatic quantification of the iodine content at the level of the microcirculation.
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Eleven nonsmokers scanned in similar conditions served as a control group.
Results: Nonsmokers had no alterations in lung structure and a uniform distribution of the iodine content within upper and lower lobes and between right and left
lungs (p 0.05). Emphysematous changes were depicted in 26 smokers (68%)
including 6 patients with an upper lung zone predominance of emphysema (Group
1) and 20 patients with disseminated areas of hypoattenuation throughout both
lungs (Group 2). Perfusion scans of Group 1 patients showed: (a) a significantly
lower iodine content within lung microcirculation of the upper lobes compared to
smokers without emphysema; and (b) a significantly lower perfusion in the upper
lung zones compared to the lower lung zones, matching parenchymal destruction.
In Group 2, no significant difference in the iodine content of lung microcirculation
could be identified in comparison to non-smokers.
Conclusion: Lobar alterations of lung perfusion can be depicted by dual energy
CT in COPD patients with heterogeneous emphysema.
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14:18
Functional high-resolution digital radiography in diagnosis of chronic
obstructive pulmonary disease
N. Gorbunov, V. Laptev, S. Pushkarev; Novosibirsk/RU (n_gorbunov@hotmail.com)
Purpose: To determine pulmonary optical density and to evaluate respiratory function in patients with chronic obstructive pulmonary disease (COPD).
Methods and Materials: The study group comprised 690 patients (283 females,
407 males; mean age 47p 1.2 years, range 16-78 years). There were 419 patients
with COPD; the control group included 271 people without pulmonary complaints.
We used high-resolution digital radiographic device with a line X-ray sensitive
silicate receiver. Lowdose high-resolution digital X-ray examination of the chest
was performed both in inspiration and expiration phases. Regional and common
pulmonary optical densities were evaluated with further quantitative analysis of
respiratory function.
Results: It was determined that normal lung density is 660-770 optical density units
(odu) for young people till 45 years old, 715-790 odu for moderate age patients (4560 years old) and 790-860 odu for people of 60 and more years old. The respiratory
function of pulmonary tissue is normal in case when it is no less than 5.9 for young
people, 5.6 and more for people of 45-60 years old and no less than 4.95 for senior
people. When pulmonary optical density is lower than normal value, then patient
has pulmonary emphysema. On the opposite side, if pulmonary optical density is
higher than normal value we suppose pulmonary fibrosis. In all patients with COPD,
we observed the decrease of respiratory function. There was significant correlation
between pulmonary optical density and respiratory function (p 0.01).
Conclusion: Functional high-resolution digital radiography may be useful for
prognosis in patients with COPD and for treatment selection.
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14:27
Global and regional airway obstruction in patients with severe
homogeneous emphysema: Quantitative analysis of volumetric paired
thin section multi detector computed tomography scans and pulmonary
function tests
A. Grgic1, H. Wilkens1, J.-M. Kuhnigk2, E.-M. Jung3, G. Sybrecht1, R. Kubale4,
A. Buecker1; 1Homburg a.d. Saar/DE, 2Bremen/DE, 3Regensburg/DE,
4
Pirmasens/DE (aleksandar.grgic@gmx.de)
Purpose: To investigate the correlation of pulmonary function tests - (PFT) and
CT scans obtained in - and expiration and to assess the lobar gas trapping in
homogeneous emphysema.
Methods and Materials: 48-patients (mean age-60p9 years) with severe emphysema due to COPD-GOLD IV were included in this retrospective study. All scans
were performed during inspiration and expiration using a 16-channel MDCT. MDCTdata were analyzed with MeVisPULMO3D-software to give following parameters:
lung volume-LV, emphysema index-EI, emphysema volume-EV, core-CV to peel-PV
volume and four clusters (2, 8, 65, 120 mm³) for whole lung and each lung lobe
separately. These results were correlated with PFT-data: forced expiratory volume
in 1 second-(FEV1), inspiratory vital capacity-(VCin), residual volume-(RV), total
lung capacity-(TLC), RV/TLC and 6-minute walking distance.
Results: Inspiratory-LV correlated well with TLC (p 0.001), expiratory-LV with RV
(p 0.001). The mean inspiratory-EI of 37p9% decreased by 25p9% (p 0.001)
during expiration resulting in a change of EV by 930 p 370 ml (p 0.001). Change
of LV from inspiration to expiration correlated with RV/TLC (p 0.001), FEV1
(p 0.001) and VCin (p 0.001). Change of EV, CV, PV correlated with RV/TLC,
FEV1 and VCin (all p 0.05), but change of large emphysema clusters showed
better correlation with RV/TLC, FEV1 and VCin (p 0.001). The comparison of lobar
RV/TLC CT indexes (192 lobes) correlated well with change of lobar volume, EV,
CV, PV and large clusters (all p 0.001).
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Conclusion: While morphological changes are better reflected in the static lung
volumes obtained from MDCT, dynamic changes in PFT-data correlate better with
dynamic changes in MDCT. Lobar analysis provides better insights into the regional
hyperinflation areas.
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14:36
Short-term reproducibility of navigator-triggered oxygen-enhanced MRI of
the lung
F. Molinari1, M.U. Puderbach2, M. Eichinger2, S. Ley2, L. Bonomo1,
H.-U. Kauczor2; 1Rome/IT, 2Heidelberg/DE (fmolinari@rm.unicatt.it)
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14:45
Simulated smooth kernel images obtained by post-reconstruction filtering
of sharper kernel reconstructions in chest CT
S. Akers, H. Litt; Philadelphia, PA/US (scott.akers@va.gov)
Purpose: Clinical review of chest CT requires reconstruction, evaluation, and
storage of several image sets, including reconstructions obtained using sharper
lung and smoother mediastinal kernels. We investigated the possibility of creating
simulated mediastinal kernel images using post-reconstruction filtering of lung
kernel images.
Methods and Materials: Simulated mediastinal kernel images were created by
applying post-reconstruction filtration to lung kernel (B50f) images from 20 contrast
enhanced chest CT examinations using experimental software, allowing the user to
simulate any kernel smoother than the original. Images were compared to actual
mediastinal reconstructions (B31f). Mean attenuation was measured in 5 ROIs
(liver, spleen, lung, pulmonary artery, and outside the patient) in both sets. Differences in average mean attenuation and were evaluated with subjective perception
of mediastinal image suitability.
Results: Images could be filtered from lung to mediastinal settings instantaneously
and viewed using clinical software. There were no significant differences in mean
attenuation between the true and simulated mediastinal images in any ROI, with
average difference in mean attenuation of 1% for each. Subjectively, simulated
mediastinal images appeared somewhat sharper than actual mediastinal images,
without limiting diagnostic utility.
Conclusion: Post-reconstruction filtering of lung kernel reconstructions can
reproduce mean attenuation values of a smoother mediastinal kernel. If clinical equivalence of simulated reconstructions can be demonstrated in studies
encompassing a range of pathology, this may result in savings in scanner and
radiologist time and image storage. Additionally, radiologists would not be limited
to pre-specified reconstructions, but could choose the kernel most suitable for each
image, diagnosis, or patient.
14:54
Phenotyping of COPD: Comparison of an anatomical and a non-anatomical
approach in studying the distribution of emphysema between the upper
and lower lung
M. Owsijewitsch1, J. Ley-Zaporozhan1, J.-M. Kuhnigk2, C.P. Heussel1,
H.-U. Kauczor1, S. Ley1; 1Heidelberg/DE, 2Bremen/DE (m.owsijewitsch@dkfz.de)
Purpose: Studying the distribution of the emphysematous regions is one step
towards phenotyping COPD. We compared two currently applicable approaches
for studying the distribution of emphysema in the upper and the lower lung with
3D-HRCT, the comparison of lung lobes (anatomical) and the comparison of not
anatomically defined halves of the lung divided by a transverse plane.
Methods and Materials: We investigated 100 patients with GOLD stages 0 (at
risk)-4. A dedicated tool (MeVisPULMO3D) was used. After the automatic lung and
lung lobe segmentation, the emphysema indices (EI, 950 HU) for lobes and halves
(divided by a transverse plane at the level of carina) of each lung were calculated.
The EI of the upper lobes was compared with the EI of the upper halves and
accordingly the EI of the lower lobes with the EI of the lower halves. In the right
lung, the volume weighted means of the EIs of the upper and middle lobes were
compared with the EIs of the upper halves.
Results: In patients with GOLD stages 0, 1 and 2 (average EI 10%), differences
between the EIs of the lobes and halves for both the upper and lower lung were in
the range of 25% of the global EI and were highly significant (P 0.001), but not
significant in patients with stages 3 and 4.
Conclusion: For less severe disease groups, it is essential to perform the lobebased analysis for correctly phenotyping the disease. In GOLD classes 3 and 4
with a homogenous distribution of emphysema, there is no difference between
both approaches.
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15:03
Comparison of dynamic MRI, CT and nuclear medicine for prediction of
postoperative lung function in lung cancer
Y. Ohno, H. Koyama, M. Nogami, D. Takenaka, Y. Onishi, K. Matsumoto,
K. Sugimura; Kobe/JP (yosirad@kobe-u.ac.jp)
Purpose: To compare the predictive capabilities for postoperative lung function
in non-small cell lung cancer (NSCLC) patients of the state-of-the-art radiological
methods, including dynamic perfusion MRI, quantitative CT and co-registered
SPECT/CT, with that of anatomical method (i.e. qualitative CT) and traditional
nuclear medicine methods such as planar imaging and SPECT.
Methods and Materials: Dynamic perfusion MRI, CT, perfusion scan including SPECT and measurements of %FEV1 before and after lung resection were
performed for 229 NSCLC patients (125 men and 104 women). For perfusion
MRI, postoperative %FEV1 (po%FEV1) was predicted from semi-quantitatively
assessed blood volumes within the total and resected lungs; for quantitative CT, it
was predicted from the functional lung volumes within the total and resected lungs;
for qualitative CT, from the number of segments of total and resected lungs; for
nuclear medicine studies, from uptakes within the total and resected lungs. Predicted
po%FEV1s were then correlated with the actual po%FEV1s, and the limits of agreement between the actual and predicted po%FEV1 were evaluated.
Results: All po%FEV 1s showed good correlation with actual po%FEV 1s
(0.83brb0.88, P 0.0001). The limits of agreement of dynamic perfusion MRI
(4.4 p 14.2 %), quantitative CT (4.7 p 14.2 %) and co-registered SPECT/CT
(5.1 p 14.7 %) were less than those of qualitative CT (6.0 p 17.4 %), planar imaging (5.8 p 18.2 %) and SPECT (5.5 p 16.8 %).
Conclusion: State-of-the-art radiological methods can predict postoperative lung
function in NSCLC patients more accurately than traditional methods.
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15:12
Quantitative assessment of airway remodelling in difficult asthma
S. Gupta, R. Clark, S. Siddiqui, P. Haldar, J. Entwisle, R. Green, I. Pavord,
A. Wardlaw, C. Brightling; Leicester/UK (drsumitgupta@yahoo.com)
Purpose: Our aim was to measure airway dimensions in two different airways on
high resolution computed tomography (HRCT) in patients with difficult asthma and
compare it with healthy individuals. We also explored the correlation between dimensions of two different airways and their association with clinical characteristics.
Methods and Materials: All difficult asthma clinic (DAC) patients were extensively
characterised in terms of history, lung function, health status and airway inflammation. HRCT was performed using 16 detector multislice scanner and images
reconstructed using a bone algorithm. The geometry of right B1 (RB1) and right
B10 (RB10) airways were measured by full-width at half-maximum (FWHM)
principle using EmphylxJ© software in 106 DAC patients and 10 healthy control
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Purpose: To investigate the repeatability of diagnostic quality, signal and ventilation defects of the oxygen-enhanced (OE) maps in healthy subjects and lung
cancer patients.
Methods and Materials: OE-MRI was performed twice in 36 subjects within 24 h
(16 patients, 20 healthy volunteers; t0-24 h-t2). In the volunteers, OE-MRI was also
rapidly repeated within the first day (t0-t1). Four coronal OE-maps were obtained per
examination (dorsal to ventral; 1.5 T MR-system; navigator-triggered IR-HASTE).
Diagnostic quality (Q) and signal (S) of the maps were evaluated by 3 radiologists. 4
lung regions per map (right-upper; right-lower; left-upper; left-lower) were assessed
for ventilation defects (VD). Volunteers and patients were considered separately
(Qv; Sv; VDv; Qp; Sp; VDp).
Results: Qv/Qp was diagnostic=94.4/78.1% (sufficient=46.7/58.3%, optimal=47.8/19.8%) and not diagnostic=5.6/21.9% of times (K-inter-p=0.49-0.88;
K-intra-p=0.29-0.82). Comparing t2 and t1 vs. t0 in volunteers and t2 vs. t0 in
patients, Sv/Sp was better=27.5/31.3%, equal=51.7/37.5%, worse=20.8/31.3% of
times (K-inter-v=0.56-0.60; K-intra-v=0.15-0.44; K-inter-p=0.44). 13 VDv over 2880
regions were observed by only one reader, 2 matched among t0 and t1, none were
reproduced at t2. 44 VDp over 1536 regions were found at t0 (15 by 1, 8 by 2, 21
by 3 readers), 77 at t2 (27 by 1, 8 by 2, 42 by 3 readers), 40 matched t0 and t2 (13
by 1, 6 by 2 and 21 by 3 readers).
Conclusion: The diagnostic quality and signal of the oxygen-enhanced maps show
lower inter- and intra-observer variability in volunteers than in patients. Ventilation
defects in lung cancer patients may be reproduced after 24 hours.
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subjects. Corrections were made for the oblique orientation of the airways and
body surface area (BSA).
Results: DAC cohort and control subjects were matched for age [Mean (SEM)]:
50.6 (1.3), 49.2 (4.7), respectively. The lung functions were significantly impaired
in DAC cohort; FEV1% predicted: 74.3 (2.7), 101.2 (4.8) [p=0.005]; FEV1/FVC:
69.6 (1.4), 80.6 (2.1) [p=0.0271]. There was good correlation between corrected
RB1 and RB10 dimensions. Corrected mean (RB1 and RB10) %WA was significantly greater in DAC: mean (sem) %WA, DAC [68.4 (0.7)] and controls [63 (1.0)];
p=0.0053. Corrected RB1 %WA revealed similar results. The correlation between
corrected RB1 and clinical parameters was statistically significant for: (1) LA/BSA
and disease duration (R2=0.12); (2) %WA and FEV1% (R2=0.16), JACS (R2=0.10),
disease duration (R2=0.08), sputum neutrophils (R2=0.06). Multiple regression
analysis revealed that FEV1% best predicts RB1 %WA (R2=0.23, p=0.003).
Conclusion: The DAC group had evidence of airflow limitation and airway wall
thickening. These findings were correlated suggesting that the airflow obstruction
is in part due to airway remodelling.
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15:21
In-vivo respiratory-gated micro-computed tomography can demonstrate
airway remodeling in a mouse asthma model
M. Lederlin1, M. Montaudon1, P. Berger2, A. Ozier2, F. Laurent1; 1Pessac/FR,
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Bordeaux/FR (mathieu.lederlin@chu-bordeaux.fr)
Purpose: An imaging method for in vivo assessment of bronchial remodeling in
animal asthma models would be highly useful for preclinical studies. The aim of
our study is to evaluate the feasibility of noninvasive respiratory-gated micro-CT
for the assessment of airway remodeling in a mouse asthma model.
Methods and Materials: The study was approved by the local animal care committee. Twelve female BALB/c mice were challenged intranasally with ovalbumin.
All mice underwent plethysmographic study on day 0 and after the last intranasal
instillation. The mice were then scanned using micro-CT. On the resulting images,
peribronchial densities of 12 bronchi were measured for each mouse. The mice
were then killed and lungs examined histologically.
Results: Final analysis involved 10 out of 12 mice. A significant difference in peribronchial densities between asthmatic mice and control mice was found (p 0.05).
A strong correlation was observed between peribronchial density values and
histological parameters like peribronchovascular space (p = 0.025) and bronchial
muscle area (p = 0.018). Repeatability of measurements over observers and over
time was very good (intraclass correlation coefficients ranging from 0.94 to 0.98).
Conclusion: By measuring density of the peribronchial atmosphere, in vivo
respiratory-gated micro-CT enables to determine if a mouse is normal or asthmatic. Noninvasive respiratory-gated micro-CT appears therefore to be a reliable
methodology for monitoring bronchial remodeling in the lung and, potentially, for
evaluating the effects of new treatments.
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Room Q
Interventional Radiology
Liver: TACE
Moderators:
L. Hechelhammer; Zurich/CH
J. Tacke; Passau/DE
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Precision V: A randomized phase II trial of a drug-eluting bead in
the treatment of hepatocellular carcinoma by transcatheter arterial
chemoembolization
T.J. Vogl1, K. Eichler1, K. Malagari2, F. Pilleul3, A. Denys4, A. Watkinson5,
R. Lencioni6, M. Funovics7, J. Lammer7; 1Frankfurt a. Main/DE, 2Athens/GR,
3
Lyon/FR, 4Lausanne/CH, 5Exeter/UK, 6Pisa/IT, 7Vienna/AT
(t.vogl@em.uni-frankfurt.de)
Purpose: To compare DEB-TACE with conventional TACE for the treatment of
intermediate-stage HCC in patients with cirrhosis.
Methods and Materials: A total of 212 patients (185 males and 27 females; mean
age, 67 years) with Child-Pugh A or B liver cirrhosis and large and/or multinodular,
unresectable HCC were randomized to receive DEB (DC Bead; Biocompatibles,
UK) loaded with doxorubicin or conventional TACE with doxorubicin. Randomization
was stratified according to Child-Pugh status (A or B), performance status (ECOG
0 or 1), bilobar disease (yes or no) and prior curative treatment (yes or no). Tumor
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Hepatocellular carcinoma: The post transcatheter arterial
chemoembolization scar or tumor tissue, comparison of 3.0 T MR
diffusion-weighted imaging and PET-CT
L. Yu Bao; Guangzhou/CN (ybliu28@yahoo.com.cn)
Purpose: To evaluate the post transcatheter arterial chemoembolization (TACE)
scar or tumor tissue of hepatocellular carcinoma (HCC) by 3.0 T MR diffusionweighted imaging (DWI) and PET/CT, to analyze whether the value of ADC correlated with the post TACE scar or tumor tissue.
Methods and Materials: Twenty-two patients with HCC were enrolled in our
study. All the patients underwent TACE. 3.0 T MR diffusion weighted imaging was
performed with b value of 600 s/mm2. An Echo-planar sequence was performed.
The ADC values of the lesion after TACE were measured in diffusion weighted
images. All the patients underwent fluorodeoxyglucose (FDG) positron emission
tomography CT (FDG-PET/CT) examinations after the MR examinations. It was
analyzed whether the value of ADC correlated with the scar or tumor tissue of
HCC after TACE. The scar or tumor tissue of HCC after TACE was confirmed by
PET/CT and clinical follow-up. The values of ADC of the scar or tumor tissue and
normal liver tissue were compared. The data were analyzed by SPSS13.0 statistical
software and p 0.05 was considered to be significant.
Results: All patients with post TACE scar or tumor tissue of HCC were confirmed by
PET/CT. Compared with the results of PET/CT, the mean ADC of tumor tissue was
1.92×10-3 mm2/sec, The mean ADC of scar tissue was 6.59×10-3 mm2/sec. The mean
ADC between scar and tumor tissue were statistically significant (p=0.021).
Conclusion: The ADC value of DWI is a promising functional magnetic resonance
imaging tool for prediction of therapeutic response to TACE. Compared with PET/
CT, DWI is useful in the differential diagnosis of scar tissue and tumor tissue in
patients with HCC after TACE.
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14:18
Transarterial chemoembolization and radiofrequency ablation in the
treatment of hepatocellular carcinoma: Differentiation of viable residual
tumor with CT-perfusion technique
D. Ippolito1, F. Invernizzi2, M. Scorza1, M. Pozzi1, L. Antolini1, S. Sironi1;
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Monza/IT, 2Lecco/IT (davide.atena@tiscalinet.it)
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response at 6 months was the primary study endpoint. An independent, blinded
review of MRI studies was conducted to assess tumor response according to
amended RECIST criteria.
Results: DEB-TACE with doxorubicin showed a higher rate of complete response,
objective response and disease control compared with conventional TACE (27 vs
22%; 52 vs 44%; and 63 vs 52%, respectively; P 0.05). Patients with Child-Pugh
B cirrhosis, ECOG 1 performance status, bilobar disease and recurrence following
curative treatment showed a significant increase in objective response (P = 0.038)
compared to the control. There was a marked reduction in serious liver toxicity
in patients treated with DEB-TACE. The rate of doxorubicin-related side effects
were significantly lower (P = 0.0001) in the DEB-TACE group compared with the
conventional TACE group.
Conclusion: DEB-TACE with doxorubicin is safe and effective in the treatment of
intermediate-stage HCC and may offer a significant benefit to patients with more
advanced disease.
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Purpose: To assess the value of CT-perfusion technique (CT-p) in quantifying the residual vascularity in hepatocellular carcinoma (HCC) treated with TACE and RFA.
Methods and Materials: CT-perfusion study was performed in 72 patients with liver
cirrhosis and known diagnosis of hepatocellular carcinoma. Out of 72 patients, 53 were
treated with TACE, while the remaining 19 patients were treated with RFA. Dynamic
CT study was performed with a 16-slice multi-detector-computed tomography (Philips
Brilliance,16 P, NL) with the following protocol: acquisition of 8 dynamic slice/scan for
a total of 40 scans after i.v. injection of 50 ml of iodinated contrast (350 mgI/ml) with a
flow rate of 6 ml/sec.The data were analyzed using a dedicated software (CT perfusion
2.0 workspace), which calculated the following parameters: hepatic perfusion (HP),
blood volume (BV), arterial perfusion (AP), hepatic perfusion index (HPI), time to
peak (TTP). All the obtained data were expressed by mean o standard deviation and
were statistically analyzed using univariate Wilcoxon test.
Results: A complete treatment of neoplastic lesion was not obtained in 41 out of
72 patients in whom the following quantitative perfusion parameters were found: HP
32.7 p 15 ml/100 gr/sec; BV 17.6 p 9.5 ml/100 gr; AP 38.4 p 8.8 ml/min; TTP 19 p 5.7
sec; HPI 61.3 p 32.7%.The corresponding values obtained in the remaining 31 cases
in whom a complete necrosis was achieved were: HP 13.6 p 5.7 ml/100 gr/sec; BV
6.8 p 4.8 ml/100 gr; AP 13.1 p 7 ml/min; HPI 13.6 p 9.2 % and TTP 29 p 16.1 sec.
Our data showed that HP, AP, BV and HPI values were higher (P 0.001), whereas
Scientific Sessions
TTP was lower in HCC lesions unsuccessfully treated.These findings were related
to the presence of residual viable vascular structures.
Conclusion: CT-p technique may have a complementary role in diagnosing
residual HCC blood perfusion, thus helping in the assessment of tumor response
to treatment.
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14:27
Transarterial chemoembolization in down-staging program for
hepatocellular carcinoma prior to liver transplantation: The Bologna workin-progress experience
A. Cappelli, E. Giampalma, M. Renzulli, C. Mosconi, R. Golfieri; Bologna/IT
(alberta.cappelli@aosp.bo.it)
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14:36
Comparison of bland embolization versus drug eluting bead embolization
for the treatment of BCLC stage B hepatocellular carcinoma
K. Malagari, M. Pomoni, M. Angelopoulos, H. Moschouris, E. Emmanouil,
A. Pomoni, A.D. Kelekis, P. Vasiliou, D. Kelekis; Athens/GR (kmalag@acn.gr)
Purpose: To evaluate the added role of the chemotherapeutic in transarterial
embolization (TACE) of intermediate stage hepatocellular carcinoma (HCC). The
issue is of major importance since hypoxia is a potent stimulator of angiogenesis.
This is suggested by recent evidence that shows that bland embolization increases
the serum levels of angiogenic factors such as VEGF and insulin growth factor.
Several studies up to now have shown that chemoembolization performs better
than bland embolization but the variability of the parameters of TACE compromise
the strength of these results. The hypothesis was that since DEB-TACE allows a
standardized and reproducible TACE the comparison with bland TACE can readily
reveal the potential added value of the chemotherapeutic.
Methods and Materials: Two groups of patients were enrolled in this prospective
study: group A- treated with doxorubicin DEB-TACE (n = 20) and group B (n =
22) treated with bland embolization. Patients included were BCLC stage B, with
measurable lesions randomized for tumor size.
Results: Tumor response was evaluated with the RECIST criteria using the EASL
amendment. In group A complete response on an intention to treat basis was seen
in 6 patients (30%). Objective response ranged from 65% to 80% across treatments.
In group B complete response was achieved in 18.18% while objective response
ranged from 50% to 68.18% across treatments. There were no significant differences in the levels of AFP between the two groups.
Conclusion: DEB-TACE with DC bead presents better tumor response than bland
embolization; however, survival benefit has to be shown in future studies.
14:45
First evaluation of a phase III study comparing TACE-DC beads IRI loaded
(DEBIRI) with FOLFIRI (CT) for patients with nonresectable colorectal
cancer (CRC) and liver metastases (LM)
C. Aliberti1, G. Benea1, M. Tilli1, I. Marri1, G. Fiorentini2; 1Ferrara/IT, 2Empoli/IT
(camy.ali@libero.it)
Purpose: Patients with LM from CRC have a poor prognosis with a 5-year survival
of 25% after radical resection, and for not resectable metastases the survival is less
than 5%. DC beads are new embolic microspheres capable of loading IRI. DEBIRI
(D) is a combination of drug infusion with embolization of the LM feeding arteries. It
is a safe and feasible procedure (ASCO GI abs 356, Jan 2007; IN VIVO 21, 6, 2007;
ASCO GI abs 480, Jan 2008). CT containing IRI is active for the treatment of LM
from CRC. We planned this phase III study to assess survival as primary endpoint
with the goal to increase median survival (MS) by 40% at 2 y (HR = 0.72).
Methods and Materials: Between December 2006 and August 2008, 56 patients
were randomized, 28 to D (DC Beads loaded with IRI 200 mgr total dose) and 28
to CT. A total of 52 cycles of D were administered, with a relative dose intensity of
99%, and 224 CT cycles were delivered with a relative dose intensity of 85-95%.
Results: D increased the 1y MS difference of 20% compared to CT. It improved
responses and performance status and reduced costs. D reported higher immediate toxicity, mainly fever, abdominal pain and vomiting, than CT. Intravenously,
hydration, morphine and antibiotics were necessary to control these symptoms.
Late toxicity, mainly leukopenia, anemia, diarrhoea, asthenia and alopecia, was
more common in CT.
Conclusion: We conclude that D could reach the goal to increase MS by 40% at
2 y compared to CT.
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14:54
Repeated chemoembolisation treatment of liver metastases from
neuroendocrine tumors: Survival rates and local tumor control
T.J. Vogl, S. Zangos, K. Eichler, M. Nabil, T. Gruber; Frankfurt a. Main/DE
(t.vogl@em.uni-frankfurt.de)
Purpose: To assess, using a combined protocol of Mitomycin C and Gemcitabine,
the morphological response and survival rates of patients with hepatic metastases
of the neuroendocrine tumor.
Methods and Materials: A total of 44 patients (range, 37-77 years) with liver
metastases from neuroendorine tumors underwent repeated selective chemoembolization using Mitomycin C and Gemcitabine between 1999 and 2007. Monthly
follow-up was performed by CT and MRI for local tumor control.
Results: A total of 244 chemoembolizations were performed with a mean of 5.5
sessions per patient at 4-week intervals. Of all the patients, 25 had multiple metastases, 13 had one metastasis, 1 had two metastases, and 5 had three to four
metastases. The local chemotherapy protocol consisted of Mitomycin C only (n =
17) and Mitomycin C with Gemcitabine (n = 27). Local tumor control according to the
RECIST criteria showed partial response in 13.64% of patients, stable disease in
63.64% and progressive disease in 22.72%. The 1-year survival rate was 88% and
the 2-year survival rate was 74. The median survival time from the date of diagnosis
was 88 months (according to Kaplan-Meier) and after the first chemoembolization,
40.7 months. For the palliative group, it was 36.9 months, for the symptomatic group
16 months and for the neoadjuvant group 46.6 months.
Conclusion: Repeated TACE using Mitomycin C and Gemcitabine allows effective
local tumor control and improved survival rates in patients with liver metastases
of neuroendocrine tumors.
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Transarterial chemoembolization (TACE) of liver tumors or metastases
using drug-eluting beads (DEB): Complications observed
I. Kralj1, E.-P. Strecker1, I. Boos2; 1Karlsruhe/DE, 2Woerth/DE (i.boos@gmx.net)
Purpose: TACE using DEB is a relatively new kind of therapy having been proposed
as a safe and effective method for highly selective and precise embolization of
hepatocellular carcinoma and liver metastases. We will report on a few interesting
cases of insufficient results and complications.
Methods and Materials: 17 patients underwent 29 TACE embolizations using DC
Beads loaded with epirubicin or doxorubicin. When the right and left sides were
involved, TACE was performed in two sessions, one side per session. CHILD-C
cirrhosis was regarded as contraindication. During the patient’s in-hospital stay
after TACE, clinical and laboratory data were assessed. Morphologic response
was evaluated with computed tomography (CT) shortly after TACE and repeatedly
at follow-up examinations, the longest being 18 months.
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Purpose: To assess the efficacy and the safety of Trans-arterial Chemoembolization (TACE) in inducing complete tumor necrosis in HCC-patients, confirmed by the
histology after liver transplantation (LT). To analyze the overall survival and the tumor
recurrence rate of patients both within and exceeding the Milan criteria (MC).
Methods and Materials: During 2003-2007 we prospectively analyzed the outcome of 173 patients listed for LT divided in 3 groups: single nodule 3 cm (T1,
37 pts); single nodule b5 cm or multiple nodules b3 with a diameter b3 cm (T2,
93 pts) meeting the MC and the down-stage group (T3, 43 pts): single HCC b6 cm
or multiple nodules b6 with a total diameter b12 cm. Eighty-two patients (68.3%)
underwent TACE: 7 in T1 (18.9%), 46 in T2 (49.5%), 29 in T3 (67.4%).
Results: Histology after LT demonstrated a complete tumor necrosis in 61 patients (74.4%) and partial necrosis in 21 patients (25.6%). The degree of necrosis
directly correlated with the selectivity of TACE: 80.6% of cases were treated with
superselective TACE versus 46.7% with a lobar TACE. After a median follow-up of
28.3 months, the overall tumor recurrence rate was 14.6% and the overall survival
was 82%. The recurrence rate was comparable among the groups and it did not
affect significantly the patients survival.
Conclusion: TACE is safe and effective in obtaining a complete tumor necrosis
when performed in a superselective way compared to lobar procedures. The preoperative tumor stage does not affect patient survival and the down-stage group
had comparable outcome than the others.
B-446
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Results: Pain was observed in all patients, 1 patient had high-grade pain requiring
peridural analgesia. Severe procedure-related complications: necrotizing cholecystitis (2), one of them necessitating cholecystectomy; necrotizing pancreatitis
(1); partial liver necrosis and abcess (1); gastric ulceration (1); pleural effusion (1).
Further observations: small splenic infarction (1); gas within embolized area (2);
and incomplete embolization (2).
Conclusion: DEB is highly effective in embolization of liver tumors. As according
to a rapid and complete occlusion of arteries, the risk of adverse side effects may
be high also. From our experience, we recommend embolization of the cystic artery
in case of tumor localization near the gallbladder.
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B-449
B-451
15:12
Palliative and symptomatic treatment of primary hepatic
cholangiocarcinoma with repeated transarterial chemoperfusion and
embolization: Local tumor control and survival rate
T.J. Vogl, S. Zangos, K. Eichler, T. Gruber; Frankfurt a. Main/DE
(t.vogl@em.uni-frankfurt.de)
Purpose: To evaluate the local tumor control and survival data in the palliative
and symptomatic treatment of hepatic cholangiocarcinoma (CCC) using repeated
transarterial chemoperfusion and embolization (TACE) with two different chemotherapy protocols.
Methods and Materials: A total of 41 patients with primary cholangiocarcinoma
(CCC) were repeatedly treated with transarterial chemoembolization (TACE) at
4-week intervals. In total, 291 TACE sessions were performed with a mean of 7.1
sessions per patient (mean age: 57.1 years; range, 37-80 years). Of all the patients,
22 had multiple tumors, 6 showed one lesion, 5 had two lesions and 8 presented
with three to four lesions. The local chemotherapy protocol consisted of Mitomycin
C alone (n = 20) or in combination with gemcitabine (n = 18). Embolization was performed with lipiodol and starch microspheres for vessel occlusion. Tumor response
was evaluated by magnetic resonance imaging (MRI) at 3-month intervals.
Results: The evaluation of local tumor control according to RECIST criteria was
as follows: partial response 9.8%, stable disease 43.6% and progressive disease
46.6%. The 1-year survival rate after TACE was 58% and the 2-year survival rate
was 21%. The mean survival time from the date of diagnosis of liver involvement
was 34.1 months (according to Kaplan-Meier) and after the first TACE treatment,
16.7 months. The median survival time of the palliative group was 14.5 months
and of the symptomatic group 6 months.
Conclusion: Our data indicated that repeated TACE using the protocols is well
tolerated and yields respectable results in patients with unresectable liver lesions
from CCC.
B-450
15:21
Angiographic cone beam C-arm volume CT with a flat panel detector prior
to TACE: Does it add useful information on the arterial tumor supply and
portal veins?
B.C. Meyer, B.B. Frericks, M. Witschel, K.J. Wolf, F.K. Wacker; Berlin/DE
(Bernhard.Meyer@Charite.de)
Purpose: To assess the arterial tumor supply and portal vein with C-arm CT (CACT)
in comparison to DSA in patients undergoing TACE of the liver.
Methods and Materials: A total of 30 patients (hepatocellular carcinoma, n = 10,
malignant ocular melanoma, n = 12, hypervascular liver metastases, n = 8) underwent arterial and portal venous CACT (breath-hold technique, resolution 0.4 mm³) of
the liver using intraarterial contrast media administration as well as DSA immediately
prior to TACE. After assessing the DSA images, CACT images were reviewed on a
3D workstation. Number and origin of the tumor feeding arteries, ideal position of the
catheter for TACE, presence of segmental portal vein thrombosis and of breathing
artifacts in both, DSA or on CACT, were assessed and correlated.
Results: The number of vessels identified as tumor feeders was significantly
higher in CACT than in DSA (CACT: 1.4 p 0.6 and DSA:1.0 p 0.3, P = 0.003,
t-test). After consideration of the CACT images, the position of the catheter for
TACE was changed in 15 cases to a less selective position (n = 9) or to a more
selective position to presevere healthy liver tissue (n = 3) or the gall bladder (n =
3). Breathing artifacts were observed in both, CACT (n = 3) and DSA (n = 2), but
did not interfere with image interpretation. A segmental portal vein thrombosis was
seen in three patients in CACT, but only in one in DSA.
Conclusion: As CACT depicts soft tissue as well as small vessels in high-spatial
resolution, tumor vessel allocation is facilitated and the ideal catheter position for
TACE can be chosen more precisely. Due to the higher contrast resolution of CACT
in comparison to DSA, portal vein pathologies are better visualized.
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Imaging viability and valve disease
Moderators:
J. Barkhausen; Lübeck/DE
S. Potthast; Basle/CH
14:00
Impact of radiation dose and contrast material volume in the assessment
of acute reperfused myocardial infarction with 64-slice delayed
enhancement CT: A porcine model
C. Martini1, E. Maffei1, A.A. Palumbo1, C. Saccò1, M.L. Dijkshoorn2,
A.C. Weustink2, N.L. Mollet2, F. Cademartiri1; 1Parma/IT, 2Rotterdam/NL
(erimaffei@libero.it)
Purpose: To compare the impact of dose and contrast material volume in DelayedEnhancement CT imaging for the assessment of acute reperfused myocardial
infarction.
Methods and Materials: In ten 2-month-old domestic pigs (mean weight: 24 kg),
circumflex coronary artery was balloon-occluded for 2 h followed by reperfusion.
After 5 days, DE-CT imaging was performed 15 min after administration of iodinated contrast. The scan protocol was performed in spiral cardiac mode: fixed pitch
(0.2), HR (51 p 9 bpm; pharmacologically induced), at two tube current values
(350/900 mAs) with two iodinated contrast material volume (30/100 ml). The scans
performed were: ART (CTA first-pass), DE1 (15 mAs/kg-1.25 gI/kg), DE2 (37.5 mAs/
kg-1.25 gI/kg), DE3 (15 mAs/kg-3.75 gI/kg), DE4 (37.5 mAs/kg-3.75 gI/kg). Infarct and
no-reflow size were defined as the hyperenhanced and dark area, respectively, and
expressed as percentage of total remote myocardial area. CT attenuation values
were measured using five regions of interest: DE, no-reflow, remote myocardium,
left ventricular cavity, air, respectively. Differences, correlations, S/N and C/N were
calculated.
Results: Infarct area showed a significant increase with higher dose and contrast
material volume with best visualization in DE4. S/N and C/N were the highest for
DE 2.4 (6.0 and 3.6, respectively) as compared to DE 1.3 (4.0 and 2.2, respectively).
Significant differences were found between the Hounsfield-Unit of DE 2.3 versus
DE 3.4, however the correlation was very high including the S/N and C/N
(R2 0.90).
Conclusion: The amount of contrast material is far more important than radiation
dose for the assessment of DE-CT. The best DE-CT can be obtained with a volume
of contrast material which is 2-3 times the amount usually employed for standard
Cardiac-CT in humans.
B-452
14:09
Influence of time-to-reperfusion on the extent of the area at risk (RA),
infarct size (IS) and microvascular obstruction (MVO) in patients with STelevated acute myocardial infarction (STEMI): A cardiovascular magnetic
resonance (CMR) study
M. Francone, L. Agati, F. Vasselli, I. Iacucci, J. Carbone, C. Catalano,
R. Passariello; Rome/IT (marco.francone@uniroma1.it)
Purpose: Salvage of viable myocardium within the RA and limitation of infarct expansion are the mechanisms by which patients with STEMI benefit from reperfusion.
CMR with late enhancement (LE) and T2 weighted short tau inversion recovery
(T2w-STIR) imaging may represent an ideal tool for the assessment of effects of
time-to-treatment on IS, MVO and myocardium potentially salvaged.
Methods and Materials: 70 patients with first STEMI treated with PCI within 12
hours from symptoms onset underwent CMR in the first week after admission. For
the purpose of the study, patients were divided into 4 groups according to different
time-to-reperfusion intervals: Group-A ( 1.5 hrs; n=19); Group-B ( 1.5-3 hrs; n=17);
Group-C ( 3-6 hrs; n=17); Group-D ( 6-12 hrs; n=17). CMR protocol included
T2w-STIR, 1st-pass and LE sequences after Gd-BOPTA administration (Multihance,
Bracco). IS, MVO and RA were quantified from DE and T2w MRI; peri-infarction
zone was determined as the ratio between RA and IS.
Results: Median time-to-reperfusion was 4.4p4.7 hrs. Shorter time-to-reperfusion
was associated with smaller IS (Group-A: 9%; Group-B: 15%; Group-C: 14%;
Group-D: 18%; Group A vs B, C, D; p =.044).
Conclusion: Larger RA (Group-A: 25%, Group-B: 15%; Group-C: 16%, Group-D:
9%) and peri-infarction zones were also observed in patients treated earlier (Groups
AB vs CD p 0.01). Lately reperfused STEMI (Group D) had significantly larger
MVO areas (Group D vs A, B, C; p=.041) with higher prevalence of intramyocardial
Scientific Sessions
hemorrhage. This study further support the importance to shorten treatment delay
of STEMI patients and emphasizes diagnostic role of CMR protocol with LE and
T2w techniques providing in vivo characterization of tissue damage at different
temporal stages of reperfusion.
B-453
14:18
Ageing of the human heart: Can physical exercise attenuate the
morphological, functional and metabolic alterations of the left ventricle? A
magnetic resonance imaging and magnetic resonance spectroscopy study
E. Belloni, F. De Cobelli, G. Perseghin, A. Esposito, T. Canu, G. Alberti, L. Luzi,
A. Del Maschio; Milan/IT (belloni.elena@hsr.it)
B-454
14:27
Contrast-enhanced MRI is superior to PET in myocardial viability
assessment of patients with impaired left ventricular function
P. Hunold1, A. Marcin2, T. Schlosser2, K. Brandt-Mainz2, R. Pink2, L. Freudenberg2,
H. Eggebrecht2, P. Massoudy2, J. Barkhausen1; 1Lübeck/DE, 2Essen/DE
(peter.hunold@uk-sh.de)
Purpose: To evaluate MRI and PET for myocardial viability assessment in CAD
patients with different LV functional states.
Methods and Materials: 105 CAD patients were examined by MRI and PET. MRI
(1.5 T) contained a TrueFISP study to assess LV function. 8-15 min after 0.2 mmol/
kg Gd-DTPA, a segmented inversion-recovery TurboFLASH study (TR, 8 ms; TE,
4 ms; TI, 200-240 ms) was performed to quantify Late Gd enhancement (LGE) extent
based on a 6-segment model in short axes. In [18F]-FDG-PET, corresponding short
axis slices were acquired and assessed using an analogous scale. Detection of
scar and prediction of functional recovery were compared in patients with ejection
fractions (EF) of 30, 30-50, and 50%.
Results: 5508 myocardial segments were analysed. 2474 of 5508 (45%) segments
provided LE in MRI vs. PET uptake deficits in 2220 (40%) segments. Scar detection
in patients with EF 30%: MRI, 1341 (55%), PET, 1116 (46%) of 2453 segments.
In this group, functional recovery was predicted in 1456 (66%) segments by MRI
vs. 1834 (75%) by PET. In patients with EF 30-50%: scar was detected in 1022
(44%) vs. 927 (40%) of 2301 segments. Functional recovery was predicted in 1674
(72%) vs. 1852 (80%). EF 50%: scar detected in 111 (15%) vs. 177 (23%) of 754
segments. Functional recovery was predicted in 687 (91%) and 710 (94%) of 754
segments by MRI and PET.
Conclusion: Contrast-enhanced MRI detects more scars in patients with severely
and moderately impaired LV function than PET. In MRI, fewer segments are predicted to recover function after revascularization.
14:36
Microvascular obstruction after acute myocardial infarction: When is
the optimal time point for detection with contrast-enhanced magnetic
resonance imaging?
K.-F. Kreitner, N. Abegunewardene, K. Oberholzer, T. Münzel, C. Düber,
G. Horstick; Mainz/DE (kfathome@gmx.de)
Purpose: To determine the optimal time point for detection of microvascular obstruction (MO) in patients with acute myocardial infarction (AMI).
Methods and Materials: 41 patients with AMI and successful recanalization
underwent two CMR examinations at 1.5 T within 10 days, the first within 48 hours
after AMI.
For assessment of late enhancement (LE) and MO, we used an inversion prepared
2D and 3D-segmented TurboFlash sequence in short-axis orientation of the heart.
LE and MO were measured 2 (early enhancement) and 10 minutes (late enhancement) after application of 0.2 mmol Gd-DTPA /kg bw. The left ventricle was further
assessed planimetrically.
Results: Areas of MO were detected in 32/41 early and in 31/41 patients late after
contrast application at exam 1. The number decreased at exam 2 to 23/41 and
15/41 patients, respectively. MO areas decreased from 5.5 to 3.0% between early
and late enhancement (p 0.001) at exam 1, and from 5.5 to 2.6 at early enhancement (p 0.001), and from 3.0 to 1.2 at late enhancement (p 0.001) between
exam 1 and 2. Areas of LE decreased between exam 1 and 2 from 19.5 p 12.1 %
to 14.1 p 9.1% (p 0.001).
Conclusion: The real extent of MO is best assessed on images obtained 2 minutes
after contrast application and within 24-48 after acute MI. The areas of LE decreased
from the acute to the subacute phase after AMI. For assessment of prognostic
parameters, CMR imaging should be done within 48 hours after AMI.
B-456
14:45
Potential of Gd-BOPTA for assessment of myocardial viability on MRI:
Delayed enhancement imaging and measurement of T1-values
G.A. Krombach1, M. Neizel1, J. Boehringer1, H. Kühl1, C. Hahnen1,
K.-P. Lodemann2, N. Krämer1, F. Schoth1, R.W. Günther1; 1Aachen/DE,
2
Konstanz/DE (krombach@rad.rwth-aachen.de)
Purpose: To compare gadobenate (Gd-BOPTA) injected at a dose of 0.1 mmol/kg
bodyweight with a dose of 0.2 mmol/kg bodyweight of gadopentetate (Gd-DTPA)
for delineation of myocardial infarction.
Methods and Materials: In 52 patients with myocardial infarction, we obtained
delayed enhancement images after injection of either gadobenate (n=26) or gadopentetate (n=26) at a 1.5 T MR scanner and measured regional T1 values prior, 3
and 25 min after injection of contrast medium using a Look Locker sequence. On
delayed enhancement images, we obtained contrast between infarcted and remote
myocardium and assessed image quality subjectively applying a 4-point scale.
Results: In the group, that received Gd-BOPTA T1 values of remote myocardium
were 1070p125 ms, 358p78 ms and 562p108 ms prior and 3 and 25 min after
injection, and of infarcted myocardium 1097p148 ms, 246p68 ms and 373p84 ms
prior and 3 and 25 min after injection. In patients, which received Gd-DTPA T1
values were: 1087p96 ms, 325p60 ms and 555p108 ms for remote myocardium
and 1134p109, 210p43 ms and 304p83 ms for infarcted myocardium prior, 3 and
25 min after injection. Image quality of delayed enhancement images showing
myocardial infarction was rated as good (44) and excellent (28) after Gd-BOPTA
and good (51) and excellent (37) after Gd-DTPA with no significant differences
between the groups.
Conclusion: Gd-BOPTA at low dose compared to a double dose of Gd-DTPA
provides a similar contrast between infarcted and remote myocardium (0.64p14
versus 0.71p11) and slightly higher contrast between left ventricular blood and
infracted myocardium (0.22p17 versus 0.14p6). After administration of 0.1 mmol/
kg bodyweight Gd-BOPTA late enhancement images with similar image quality
compared to the standard dose of 0.2 mmol/kg of Gd-DTPA can be obtained.
B-457
14:54
Molecular multidetector computed tomography (MDCT) imaging for
visualization of deposited myocardial calcium in reperfused infarction
M. Carlsson, M. Saeed; San Francisco, CA/US (marcus.carlsson@med.lu.se)
Purpose: Calcium overload during reperfusion is a major contributor of myocardial
necrosis. This study aimed to assess the ability of 64-slice MDCT in quantifying
deposited calcium in reperfused infarction.
Methods and Materials: Reperfused infarction was produced in 7 pigs by percutaneous coronary catheterization. Animals were imaged at 2-4 hrs, 1 week and 8
weeks after reperfusion using a 64-slice GE MDCT. Baseline non-contrast imaging
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Purpose: Assess whether the ageing-related morpho-functional and metabolic
changes of the left ventricle (LV) are attenuated in middle-aged men involved in
long-lasting physical activity.
Methods and Materials: Magnetic resonance imaging (MRI) and 31Phosporousmagnetic resonance spectroscopy (31P-MRS) were performed on 20 healthy young
and 25 healthy middle-aged men with a sedentary lifestyle (11 young and 14
middle-aged) or undergoing regular aerobic training (9 young and 11 middle-aged).
Short-axis cine SSFP images, encompassing both ventricles from base to apex,
were obtained to perform LV morpho-volumetric and systolic function analysis.
Phase contrast images were obtained to perform LV diastolic function evaluation. 31P
spectra were obtained with a dedicated surface chest coil for transmission detection
of radiofrequency signals at the resonance frequency of 31P. The volume of interest
was positioned avoiding inclusion of chest wall and diaphragm muscles.
Results: The physically active individuals were characterized by higher LV mass
and volumes. Sedentary young and middle-aged men were not different in LV
morphological parameters and systolic function. The PCr/ATP ratio (marker of
phosphates metabolism) and the LV E/A peak flow ratio were lower in the middleaged sedentary than in the middle-aged physically active subjects. Parameters of
LV systolic function and the PCr/ATP ratio were not different in the middle-aged
and in the young trained men.
Conclusion: Trained middle-aged subjects showed a better pattern of LV energy
metabolism and of diastolic function than the sedentary counterparts; this could
be a preliminary evidence that in long-lasting physical activity the ageing process
of the heart is attenuated.
B-455
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(120 kV/200 mAs, 2.5 mm slice thickness covering the heart, in plane spatial resolution 0.625 mm) for calcium quantification and delayed contrast enhanced (DE)
imaging (120 kV/600 mAs, 0.625 mm isotropic voxels) after 2 ml/kg Omnipaque
300 mg/ml, for infarct quantification, were obtained. Postmortem studies were used
to confirm and measure extents of deposited calcium and infarction.
Results: Deposited calcium was evident on non-contrast enhanced MDCT in the
core of the infarction at 1week (13.6p2.7% of infarcted myocardium), but not at
2-4 hrs (0.8p0.4%). At 8 weeks small remnants of deposited calcium was found
(2.7p0.7%), suggesting calcium resorption. At 1 week, there was a correlation
between the extent of deposited calcium and infarction size (r=0.70). Attenuation of
deposited calcium was greater (89p6 HU) than remote myocardium (36p3, P 0.05).
Contrast media administration obscured the visualization of deposited calcium,
because the differential contrast with surrounding infarcted tissue diminished on
DE-MDCT. Hematoxylin eosin and calcium-specific staining (von Kossa) confirmed
the extent of deposited calcium.
Conclusion: MDCT characterized the spatial distribution of deposited calcium
in infarcted myocardium and has the unique ability to monitor progression and
regression of deposited calcium in reperfused infarction.
B-458
15:03
Evaluation of valve dynamics as a new MRI parameter in the assessment
of valvular aortic stenosis
M. Weininger, F. Sagmeister, C. Ritter, F. Weidemann, M. Beissert, D. Hahn,
H. Köstler, M. Beer; Würzburg/DE (weininger@roentgen.uni-wuerzburg.de)
Purpose: To investigate a non-invasive assessment of the valvular response to
the variation of flow during systole in severe valvular aortic stenosis using velocityencoded phase-contrast MRI (VEC-MRI) compared to invasive measurements and
transthoracic echocardiography (TTE).
Methods and Materials: 16 patients (8 male, 8 female; mean age 70p8) with severe
aortic stenosis (echocardiographic orifice area 1.0 cm²) were examined using
a 1.5 T MRI scanner and a standardized scanning protocol consisting of SSFP
phase-contrast velocity imaging (VEC-MRI). Temporal changes of the aortic valve
area (AVA), determined by manual planimetry of VEC-MRI images, were used to
assess valvular dynamics by calculating the time-frame of the ejection period, which
AVAs spent over 85% of the maximal AVA. Calculations were done by dividing the
number of frames with AVA over 85% by all frames of the ejection period. MRI
results were compared to invasive measurements according to the Gorlin formula
(AVAGorlin) and the effective orifice area using TTE.
Results: Values for time spent over 85% determined by VEC-MRI were 34p14%.
Mean values of the effective orifice area (TTE) were 0.78p0.14 cm² and for the invasively calculated AVAGorlin 0.79p0.19 cm². Comparing VEC-MRI to TTE and to AVAGorlin
a significant correlation was found for both: r=0.61/p 0.05; r=0.70/p 0.01.
Conclusion: In severe aortic stenosis, a high correlation was found between MRI
measurements and clinical gold standards (TTE and invasive measurements).
VEC-MRI seems to provide a new parameter to quantify aortic valve dynamics
(opening and closing characteristics). It might help to evaluate the hemodynamic
and physiologic severity of the stenosis.
B-459
15:12
Initial experience with a low-dose protocol for prosthetic heart valve
evaluation using a 256 detector-row CT
P. Symersky1, R.P.J. Budde2, B.A.J.M. de Mol1, M. Prokop2; 1Amsterdam/NL,
2
Utrecht/NL (psymersky@gmail.com)
Purpose: CT is under investigation as a means for prosthetic heart valve (PHV)
assessment. We report our initial experience with a 256-detector row CT (MDCT)
for low-dose PHV imaging
Methods and Materials: Eight patients with one or more PHV (7 mechanical
and 2 biological prostheses; 7 aortic and 2 mitral) underwent cardiac ECG-gated
256-detector row CT (Philips iCT), using either (1) a novel low dose scan protocol
with a low-dose (120 kV, 50-80 mAs) unenhanced retrospective scan followed by
prospective gated CTA (120 kV, 200-250 mAs) at maximum valve opening and
closure or (2) a standard retrospectively gated CTA (120 KV 600-700 mAs). Systematic PHV analysis using both static and dynamic images included the prosthesis
(leaflet motion, thrombus), annulus (periprosthetic leak, pannus) and supra- and
subvalvular anatomy (septal hypertrophy, false aneurysms).
Results: Five patients were scanned using the novel scan protocol. The standard
protocol was used in 3 because of arrhythmia, a relatively radiolucent biological valve
or additional aortic imaging. Resultant mean dose was 3.55 and 8.25 mSv, respectively. Scan indications included elevated pressure gradient on echocardiography
(n=5), suspected thrombus formation (n=2) or follow-up evaluation (n=1). All 9 valve
prostheses were successfully visualized with limited artefacts. Prospective gating
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missed full opening in one biological valve. MDCT findings included: normal valve
functioning (n=2), subvalvular calcification (n=3), narrowed left ventricular outflow
tract (n=1), leaflet restriction (n=1) and subvalvular pannus tissue (n=2).
Conclusion: 256-detector row CT using a low-dose protocol is a promising technique for prosthetic heart valve assessment that provides detailed anatomical
information.
B-460
15:21
MRI assessment of valve dynamics as a new predictor of left ventricular
mass regression in patients with severe aortic stenosis before and after
valve replacement therapy
M. Weininger, F. Sagmeister, C.O. Ritter, F. Weidemann, M. Beissert, D. Hahn,
H. Köstler, M. Beer; Würzburg/DE (weininger@roentgen.uni-wuerzburg.de)
Purpose: To validate the hemodynamic and clinical relevance of a non-invasive MRI
assessment of valvular dynamics in severe aortic stenosis by determining the leftventricular hypertrophy and regression of hypertrophy after valve replacement.
Methods and Materials: 22 patients (13 male, 9 female, mean age 68p10) with
severe aortic stenosis (echocardiographic effective orifice area, EOA, 1.0 cm²)
were examined using 1.5 T MRI (SSFP phase-contrast velocity imaging, VECMRI; SSFP-cine-MRI) before and after valve replacement. Temporal changes of
the aortic valve area (AVA), determined by planimetry of VEC-MRI images, were
used to assess valvular dynamics by calculating the time-frame of the ejection
period, which AVAs spent over 85% of the maximal AVA. MRI also determined
left-ventricular hypertrophy (LVMI) before/after therapy, and left-ventricular mass
regression (LVMR). MRI was compared to EOA and mean transvalvular pressure
gradients (PG), determined by transthoracic echocardiography (TTE).
Results: Values for time spent over 85% were 33p16%. Mean MRI values of LVMI
before valve replacement were 94p22 g/m², after valve replacement 72p17 g/m².
Extent of LVMR was -23p18 g/m² (-24%). Comparing VEC-MRI to left-ventricular
hypertrophy significant correlations were found to LVMI before therapy (r=-0.622/
p=0.002) and LVMR (r=0.624/p=0.002). TTE mean values before/after therapy were:
EOA 0.78p0.15 cm²/1.91p0.45 cm²; PG 52p18 mmHg/14p5 mmHg. Compared to
TTE, MRI significantly correlated to EOA (r=0.482, p=0.023) and PG (r=-0.535,
p=0.01) before therapy and to the extent of change of PG before/after therapy
(r=0.49, p=0.022).
Conclusion: MRI parameters of aortic valve dynamics are associated with LVMI
and LVMR after valve replacement. MRI correlates with TTE parameters of hemodynamic severity and their postoperative changes.
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Sunday, March 8
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room A
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room B
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room E1
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room E2
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SF 9c
Special
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Optimising
imaging
from fetus to
adolescent
(p. 64)
10:30
EM 3
ESR meets
Croatia
Breast
imaging and
interventional
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Croatia today
(p. 69)
11:00
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10:30
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prostate
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(p. 250)
SS 1002
Breast
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surgery
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SS 1001b
Abdominal
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(p. 258)
12:00
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(p. 70)
13:00
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GE
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(p. 527)
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GE
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(p. 527)
13:00
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14:00
14:00
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14:30
15:00
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RC 1213
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13:30
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09:30
10:00
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19:00
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room L/M
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room N/O
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room P
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room Q
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room R
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room U
2nd level
room W
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room X
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room Z
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07:00
07:00
07:30
07:30
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08:00
08:30
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Scientific Sessions
10:30 - 12:00
Room B
SS 1010
Knee and cartilage
Moderators:
G.M. Allen; Oxford/UK
E.E. Drakonaki; Iraklion/GR
10:30
Multicenter trial of preoperative knee MRI: Variability of diagnostic
effectiveness
S.P. Morozov, S.K. Ternovoy, A.V. Korolev, P.A. Felisteev, J. Maryasheva,
I. Smitienko; Moscow/RU (spmoroz@gmail.ru)
Purpose: To analyze variability of preoperative knee MRI by means of multiinstitutional study and to investigate limitations of the diagnostic method.
Methods and Materials: The study included 200 patients who had had MRI
performed at 4 independent diagnostic centers. All patients were arthroscopically
operated by 1 orthopedic surgeon. Diagnostic effectiveness of MRI was analyzed
for each intra-articular structure (6 cartilage regions, both menisci, both cruciate
ligaments) with stratification by diagnostic centers. Analysis of variability was based
on identification of objective (type of MR system, imaging protocol) and subjective
(incorrect interpretation) limitations. Clinical decision rules were developed on the
basis of cost-effectiveness analysis.
Results: Analysis of combined data provided highest MRI accuracy for posterior
cruciate ligament tears (94%), patello-femoral and lateral femoral condyle cartilage
defects (85; 81%). Highest PPV (94%) was found for anterior cruciate ligament
tear. Highest PPV was found for anterior cruciate ligament tears (94%) and medial
femoral condyle cartilage defects (87%). Highest NPV was found for posterior cruciate ligament tears (99%) and patello-femoral cartilage defects (87%). The greatest
variations of sensitivity were found for diagnosis of posterior cruciate ligament tear
and lateral tibial condyle defects. The greatest variations of specificity were found
for diagnosis of anterior cruciate ligament and menisci tears. Major reasons for low
diagnostic effectiveness were incomplete imaging protocol and misinterpretation
of MRI symptoms.
Conclusion: Preoperative MRI of knee joint is characterized by high variability of
diagnostic effectiveness. Standardized imaging protocol and correct interpretation
of MRI symptoms are pre-requisites for including MRI into clinical decision rules.
B-462
10:48
Evaluation of knee cartilage with MDCT arthrography: Morphological
assessment, study on washout and comparison with arthroscopy
B. Graca, A. Gil-Agostinho, A. Marques, F. Santos-Silva, A. Nascimento,
F. Caseiro-Alves; Coimbra/PT (brunomiguel@inbox.com)
Musculoskeletal
B-461
B-463
10:39
MRI of the knee: Does field strength influence diagnostic accuracy and
interobserver correlation?
W.W. Krampla, M. Roesel, K. Svoboda, A. Nachbagauer, M. Gschwantler,
W.F. Hruby; Vienna/AT (wolfgang.krampla@wienkav.at)
Purpose: The accuracy of the reports are taken for granted when a patient is
referred for an MRI of the knee. In this paper, the inter-observer variance regarding the interpretation of internal structures of the knee was subjected to statistical
analysis while taking the field strength of the apparatus into account.
Methods and Materials: A total of 52 MRI studies of knee joints (acquired at
1.0, 1.5 and 3 Tesla scanners) were interpreted by 11 radiologists independently.
Their reports were compared and inter-observer variance was calculated. The
findings were compared with the intraoperative situs. Specificity and sensitivity
were evaluated in the meniscus, cartilage and anterior cruciate ligament for each
field strength.
Results: Inter-observer correlation (kappa) ranges between 0.313 for the retropatellar cartilage and 0.597 for tears in the posterior horn of the medial meniscus.
The values do not increase with the field strength. The number of false positive and
false negative reports are highly dependent on the observer and do not correlate
strongly with the technical equipment. Sensitivity ranges from 10% for tears of the
anterior horn of the lateral meniscus to 87% for lateral chondral defects.
Conclusion: Inter-observer correlation is generally low, although the diagnostic
criteria are defined. The use of the classification scheme is strongly observer dependent and should be standardized by uniform training. The individual experience of
the radiologist is of higher importance than the field strength of the MRI scanner.
Purpose: To evaluate the diagnostic accuracy of arthrography with multidetector
computed tomography (arthro-MDCT) in detecting hyaline cartilage abnormalities
of the knee joint, using diagnostic arthroscopy as the gold standard. To investigate
enhancement washout in articular cartilage.
Methods and Materials: Knee arthro-MDCT images prospectively obtained in 23
patients (age range, 16-75 years; 12 female, 11 male) were evaluated for cartilage
lesions. Unenhanced MDCT was followed by enhanced MDCT immediately and
150 min after administration of intra-articular iodinated contrast. Two radiologists
analyzed the presence of lesions and CT enhancement washout on the cartilage
surfaces. The sensitivity and specificity of arthro-MDCT for cartilage lesions and
the Spearman correlation coefficient between arthrographic and arthroscopic
grading were determined. CT enhancement washout was compared in cartilage
without and with lesion (grade 1 or higher). Statistical analysis was performed with
the Student t test.
Results: At arthro-MDCT, sensitivities and specificities ranged between 72 and
74% for the detection of grade 2 or higher cartilage lesions, and between 85 and
81% for the detection of grade 3 or higher cartilage lesions. Spearman correlation
coefficients between arthro-MDCT and arthroscopic grading ranged between 0.454
and 0.851. Mean enhancement washout of abnormal cartilage was higher than that
of normal cartilage (18.8 HU p 62.9 [sd] vs -4.2 HU p 56.5, respectively; p .05).
Conclusion: Arthro-MDCT is a valuable method for the assessment of cartilage
lesions of the entire knee. Abnormal cartilage exhibits greater washout of contrast
material than normal cartilage. The evaluation of CT enhancement washout may
contribute positively to the characterization of cartilage lesions.
B-464
10:57
T1 (Gd) gives comparable information as delta T1 relaxation rate in
dGEMRIC evaluation of cartilage repair tissue
S. Trattnig1, D. Burstein2, P. Szomolanyi1, K. Pinker1, G.H. Welsch1, T.C. Mamisch3;
1
Vienna/AT, 2Boston, MA/US, 3Berne/CH (siegfried.trattnig@meduniwien.ac.at)
Purpose: To evaluate the relationship between T1 after intravenous (IV) contrast
administration (T1 (Gd)) and $relaxation rate (subtraction of inverse relaxation
time T1 after IV Gadolinium (T1 (Gd)) and native inverse relaxation time T1) in the
dGEMRIC technique of articular cartilage repair tissue.
Methods and Materials: Thirty MR examinations after matrix-associated autologous chondrocyte transplantation (MACT) of knee joint with different post-operative
intervals were examined at 3 T. T1 mapping using a variable flip-angle 3D-GRE
was performed before and after contrast administration (dGEMRIC). T1 (Gd)
and $R1 were calculated for repair tissue and normal cartilage. MR exams were
subdivided into three postoperative groups (24 months). Spearman correlation
coefficients were calculated.
Results: The correlation coefficients were highly significant between T1 (Gd) and
$R1 for repair tissue (R: -969) and normal reference cartilage (R: -0.928). The correlation was highly significant for repair tissue in early, middle and late postoperative
interval after surgery (R values: -0.986; -0.970 and -0.978). For both metrics, highly
significant differences (P 0.01) between early follow-up and the two later groups
for cartilage repair tissue were found.
Conclusion: The high correlation between T1Gd and DR1 and the comparable
conclusions reached utilizing either metric imply that T1 mapping before intravenous administration of MR contrast agent is not necessary for the evaluation of the
repair tissue. This will help to reduce costs, inconvenience to the patients, simplify
the examination procedure and make dGEMRIC more attractive for follow-up of
patients after cartilage repair surgeries.
B-465
11:06
Semiquantitative assessment of focal cartilage lesions of the knee: A
comparison of fat-suppressed intermediate weighted fast spin echo and
double echo steady state sequences at 3.0 T MRI
F.W. Roemer1, C.K. Kwoh2, M. Hannon2, M.D. Crema1, C.E. Moore3, J.M. Jakicic2,
S.M. Green2, Z. Dhina1, A. Guermazi1; 1Boston, MA/US, 2Pittsburgh, PA/US,
3
Houston, TX/US (f.w.roemer@gmx.de)
Purpose: A multitude of dedicated cartilage sequences are available in modern MRI
scanners, but it is unknown if these sequences are equally useful for semiquantitative scoring of focal defects. The aim of the study was to compare the assessment of
focal cartilage damage using the double echo steady state (DESS)- and intermediate weighted fast spin echo (IW)-sequences on a 3.0 T MRI system.
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Methods and Materials: The JOG-study includes 177 subjects aged 35-65 with
frequent knee pain and radiographic osteoarthritis. A 3.0 T MRI of both knees was
performed at baseline. Cartilage status was scored according to the WORMS system
using all the available five sequences. A total of 245 superficial or full-thickness
focal defects were detected. In a consensus reading, the lesions were evaluated
side by side using only the sagittal DESS- and IW-sequences. Lesion conspicuity was graded from 0-3. High or low signal changes adjacent to the defect were
noted as present or absent and the sequence that depicted the lesion with the
larger size was noted. Wilcoxon statistics were used to determine the differences
between the two sequences.
Results: Of the scorable lesions, 37 were in the medial tibio-femoral, 47 in the
lateral tibio-femoral and 126 in the patello-femoral compartments. Conspicuity was
superior for the IW sequence (P 0.001). The DESS sequence showed significantly
more associated signal changes (P 0.001). The IW sequence depicted the focal
lesions with larger size (P 0.001).
Conclusion: The cartilage-dedicated DESS-sequence was inferior to the IWsequence in depicting the number and size of focal cartilage defects. More additional
intrachondral signal changes were observed with the DESS, but the significance
of this finding is unclear.
B-466
11:15
MRI of retropatellar cartilage with 7T high resolution in volunteers and
patients
J.M. Theysohn1, O. Kraff1, S. Maderwald1, O. Bieri2, H.H. Quick1, M.E. Ladd1,
S.C. Ladd1; 1Essen/DE, 2Basel/CH (jens.theysohn@uni-duisburg-essen.de)
B-467
11:24
MRI of the knee at 3 T - first clinical results with a highly resolved isotropic
PD FS-weighted 3D-TSE-sequence
M. Notohamiprodjo1, A. Horng1, M. Pietschmann1, W. Horger2, J. Park2,
J. Raya Garcia del Olmo1, K.A. Herrmann1, M.F. Reiser1, C. Glaser1; 1Munich/DE,
2
Erlangen/DE (mike.notohamiprodjo@med.uni-muenchen.de)
Purpose: To technically and clinically evaluate high-resolution knee-MRI at 3 T
with an isotropic fat-saturated (FS) proton-density-weighted (PDw) 3D-TSEsequence.
Methods and Materials: For technical evaluation the dominant knee of 10
healthy volunteers was examined with a sagittally oriented PD-FS 3D-TSEsequence (TR1200 ms/TE30 ms/voxel-size 0.53 mm3/acquisition-time 10:35 min)
on a 3 T-scanner. 0.5, 1 and 2 mm thick multiplanar-reconstructions (MPRs)
were performed in the three major planes. SNR, CNR and anatomical-detailvisualization (5-point-scale) were compared to high-resolution state-of-the-art
2D-TSE-sequences in 3 orthogonal planes (TR3200 ms/TE30 ms/voxel-size
0.36x0.36x3 mm³/total acquisition-time 12:34 min). For clinical evaluation 60 patients
with cartilage and meniscus pathologies were examined with the same techniques.
Patient 3D-datasets were assessed using 1 mm-thick MPRs. 2 radiologists independently assessed detection of abnormalities and diagnostic confidence. Arthroscopic
correlation was available for 18 patients. Statistical analysis was performed using
95%-confidence intervals, Wilcoxon-signed-rank-tests and Weighted-+.
B-468
11:33
The association of prevalent medial meniscal mucoid degeneration and
tears with cartilage loss in the medial tibiofemoral compartment over a
2-year period assessed with 3.0 T MRI
M.D. Crema1, F.W. Roemer1, M.D. Marra1, A. Guermazi1, F. Eckstein2,
M.-P. Hellio Le Graverand-Gastineau3, L. Li1, B.T. Wyman3, D.J. Hunter1;
1
Boston, MA/US, 2Salzburg/AT, 3New London, CT/US (michelcrema@hotmail.com)
Purpose: Mechanical impairment of the meniscus will alter the weight-bearing
capacities of the joint and lead to damage to the articular surface. The aim of this
study was to assess the association of different types of medial meniscal pathologies with cartilage loss in the medial tibiofemoral compartment.
Methods and Materials: A total of 161 women with and without knee osteoarthritis
participated in a longitudinal 24-month observational study. Sagittal and coronal
spoiled gradient recalled acquisitions at steady state and sagittal T2-weighted
fat-suppressed sequences were acquired. Four grades of meniscal lesions were
assigned for the anterior horn, body and posterior horn: 0 (normal), 1 (mucoid degeneration), 2 (single tears), and 3 (complex tears/maceration). Cartilage morphometry was performed in different tibiofemoral subregions using segmentation and
computation software. Multiple linear regression models (grade 0 as the reference
group) were applied for the analysis with cartilage thickness loss as the outcome.
The results were adjusted for age, BMI and medial meniscal extrusion.
Results: Cartilage loss at follow-up in the medial tibia (0.04, P = 0.035) and the
external medial tibia (0.068, P = 0.037) was significantly increased for compartments with grade 3 lesions only, compared to knees with non-pathologic menisci.
Cartilage loss at the external medial tibia appears related to tears of the posterior
horn (0.074, P = 0.025).
Conclusion: The protective function of the meniscus appears to be preserved even
in the presence of mucoid degeneration and/or single tears. Prevalent complex
tears and meniscal maceration are associated with increased cartilage loss in the
same compartment, especially at the posterior horn.
B-469
11:42
Meniscal repair: MRI follow-up with clinical correlation
A. Alcalá-Galiano, B. Merry del Val, Á. Nóvez, M. Pérez Atienza, J. Acosta, J. Ayala,
M.J. Argüeso Chamorro; Coslada, Madrid/ES (aalcalagaliano@gmail.com)
Purpose: There are relatively few studies of imaging following meniscal repair, fewer
with clinical correlation. Our purpose was to correlate postoperative appearance
on conventional MR of sutured menisci with clinical findings.
Methods and Materials: A total of 24 patients presenting longitudinal tears
underwent arthroscopic repair, performed with resorbable arrows with “all-inside”
technique, different sutures were added depending on the extension of tear (62
suture points total) from 2005 to 2008. Follow-up was with conventional MR and
concurrent clinical examination; time since surgery was 6 months-3 years. Morphology and signal intensity were used to classify repaired menisci in 3 groups:
group 0, normal or correctly healed; group I, signs not conclusive of retear; group
II, failed healing or retear.
Results: Seventeen cases (71%) are affected by medial meniscus and 7 (29%) by
lateral meniscus. Eleven cases are affected by peripheral tears, 7 affecting body
and posterior horn and 8 bucket-handle tears. In total, 58% are included in group 0,
mostly peripheral tears of posterior horn, 41% in group I, and 8% in group II, both
arthroscopically confirmed bucket-handle retears. Morphological and signal changes
were significantly related to the extension of tear and number and type of sutures.
Repaired bucket-handle tears displayed most evident signal alterations, “all-inside”
resorbable devices produced subtle changes. All patients except 2 retears were
clinically healed. Clinical correlation proved most helpful in group I.
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Purpose: MRI plays a central role in the diagnosis of degenerative musculoskeletal diseases. The limitations in cartilage assessment at established magnetic
field strengths of 1.5 T or 3 T, however, are well known. Detailed detection and
classification of cartilage defects depend on high spatial resolution as well as
high contrast between diseased and normal cartilage. We evaluated the potential
benefit of 7T, compared to 1.5 T, in evaluating the retropatellar cartilage in volunteers and patients.
Methods and Materials: Eight healthy volunteers and five patients with known
retropatellar pathologies underwent PD/T2, MEDIC, DESS and SSFP (only 7T) at
1.5 (Avanto, 8-channel head coil) and 7T (Magnetom 7T, both Siemens Healthcare).
The 7T sequences had been previously optimized with regard to spatial resolution
and contrast (imaging time 8 min each). Volunteers were used to compare image
quality at both field strengths and between three different transmit-receive coils
(only at 7T). The best 7T coil with regard to SNR of the retropatellar cartilage was
used in patients. Field strengths and sequences were graded based on cartilage
details and visualization of pathologies (three-point scale).
Results: Imaging with 7T provided higher resolution (0.35 x 0.35 mm² in-plane).
SNR of the retropatellar cartilage at 7T was highest for the loop coil (SNR gain
1.8-3.6 in MEDIC, DESS and SSFP compared to the second best coil). Cartilage
detail and pathology depiction were graded to be higher at 7T. PD/T2 coverage at
7T was limited by SAR.
Conclusion: Depiction of cartilage structures and pathologies is improved at 7T.
Imaging at 7T will add supplementary information to established field strengths for
cartilage pathology, especially if dedicated coils are used.
Results: Compared to 2D-TSE 1 mm-thick 3D-TSE-MPRs provided comparable
SNR and CNR and superior visualization of small structures such as meniscalroots (3D-TSE:4.9p0.1; 2D-TSE:4.4p0.3; p 0.05). Arthroscopic correlation showed
no significant differences between 2D- and 3D-sequences. One reader detected
significantly more cartilage-abnormalities with the 2D-TSE-sequence (3D-TSE:133;
2D-TSE:151; p 0.05). Diagnostic confidence for Grade-III-meniscus-lesions
was significantly higher in 3D-TSE for one reader (3D-TSE:4.88p0.34; 2DTSE:4.34.p0.94; p 0.05). Otherwise there were no significant differences regarding
detection of abnormalities and diagnostic confidence. Intersequence-correlation was
excellent (0.82-0.92), interreader-correlation good to excellent (0.71-0.80) and not
significantly different for both sequences.
Conclusion: 3 T enables time-efficient 3D-TSE-imaging of the knee at adequate
SNR and CNR with excellent anatomical-detail-visualization. Detection and visualization of meniscus- and cartilage-pathologies is at least comparable to stateof-the-art 2D-TSE-sequences. 3D-TSE-sequences with consecutive MPR may
become a valuable component of future knee-MRI protocols.
Scientific Sessions
Conclusion: Although still a challenge, there is high overall accuracy of MR evaluation of postoperative menisci considering both morphology and signal intensity,
especially correlating image findings with clinical evaluation. MR also serves to
evaluate concomitant complications.
B-470
11:51
The relationship of high-riding Wrisberg ligament to complete discoid
lateral meniscus
J. Kim, S.-H. Choi, J. Kwon, G. Ahn, J. Hwang; Seoul/KR
Purpose: To evaluate whether the high-riding Wrisberg ligament (HRWL) on
complete discoid lateral meniscus (CDLM) causes the lateral meniscus tear
(LMT) often.
Methods and Materials: Among 4149 knee MR, 101 knees MR imaging had
CDLM. One hundred twenty-one non-discoid lateral meniscus (NDLM) cases were
enrolled as the control group. All patients had performed arthroscopic surgery for
any kinds of intraarticular derangements (ID). The presence of the Wrisberg ligament
(WL) and the attachment level of the WL on medial femoral condyle (high-riding
Wrisberg ligament (HRWL), low-riding Wisberg ligament (LRWL)) were evaluated.
The relationship between the incidence of ID and the attachment level of the WL
on medial femoral condyle of CDLM and NDLM was analyzed.
Results: One hundred forty-one patients had WL: 73 patients (35 LRWL, 38 HRWL)
in CDLM and 68 (59 LRWL, 9 HRWL) in NDLM. There were fifty-four LMT in 141
Wrisberg (+) group and 23 LMT in 81 Wrisberg (-) group regardless of the shape
of lateral meniscus. The WL only was not a significant factor for causing the LMT
(P=0.14). There were twenty LMT on LRWL and 21 HRWL on CDLM, 8 LRWL and
5 HRWL on NDLM. The LMT was forty-one on CDLM and 13 on NDLM. LMT were
more common in CDLM (P 0.001). The coexistence of HRWL and CDLM was the
significant factor for causing the LMT (P=0.0173) by multiple logistic regression.
Conclusion: The coexistence of HRWL and CDLM was a significant factor in
causing the LMT.
10:30 - 12:00
Room C
GI Tract
SS 1001a
Rectal cancer: MRI
Moderators:
C. Savoye-Collet; Rouen/FR
S.O. Schönberg; Mannheim/DE
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10:30
Accuracy of USPIO-enhanced MRI for staging of rectal cancer: A
multicenter study in expert and 3 regional centers
M. Maas1, G.L. Beets1, M.J. Lahaye1, S.M.E. Engelen1, J.P.M. Dohmen2,
G.R.J. Opdenakker3, D.M.J. Lambregts1, J.E. Wildberger1, R.G.H. Beets-Tan 1;
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Maastricht/NL, 2Weert/NL, 3Roermond/NL (moniquemaas@live.nl)
Purpose: Ultrasmall superparamagnetic particle ironoxide (USPIO) MRI is known
to have high accuracy for predicting nodal metastases in various cancers. This
prospective study evaluates diagnostic performance of MRI for predicting T-stage
and N-stage with and without USPIO in primary non locally-advanced rectal cancer
in both general and expert centers.
Methods and Materials: From February 2003 to October 2007, 327 rectal
cancer patients received USPIO-MRI 24 hours after infusion. Sequences were
axial 2DT2WFSE, 3DT1WGRE & 3DT2*. Local radiologists predicted T-stage and
N-stage, first on T2W, thereafter on USPIO-3DT2*. Separately, the expert double
read each MR, on which selection for treatment occurred. Reference standard was
histology. ROC-analysis for prediction of tumours limited to the bowel wall (pT1-2)
and nodal involvement were performed. Interobserver agreement analyses were
performed.
Results: 130/327 were non locally-advanced patients and used for analysis (42/130
regional inclusions, 42/130 pN+). For T-stage PPV and NPV for non-experts were
87% and 67%, for experts 95 and 69%. For N-stage PPV and NPV for non-experts
were 62 and 87%, for experts 47 and 92%. With USPIO PPV and NPV for N-stage
were 57 and 95% for non-experts and 70 and 97% for experts.
Conclusion: 1. MRI can predict tumors limited to the bowel wall (pT1-2) with high
PPV for expert as well as non-experts, however, at the expense of NPV. 2. T2Wsequences (without USPIO) for nodal staging are insufficient for clinical decision
making unless read by an expert. 3. Use of USPIO-3DT2* improved diagnostic
performance for both expert and regional radiologists towards accurate selection
of pN0.
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B-472
10:39
Diagnostic performance of USPIO-enhanced MRI for nodal staging
in primary rectal cancer is dependent on the number of lymph nodes
harvested at histology
M. Maas, D.M.J. Lambregts, M.J. Lahaye, A.P. de Bruïne, G.L. Beets,
J.E. Wildberger, R.G.H. Beets-Tan; Maastricht/NL (moniquemaas@live.nl)
Purpose: Nodal involvement in rectal cancer indicates poor prognosis. Preoperative knowledge of nodes could impact treatment choice. However nodal staging
at histology is also associated with prognosis. 12-16 nodes are defined as “good
harvesting”, less as “bad harvesting”. As part of a multicenter study accuracy of
USPIO-MRI as a stratification tool for treatment of rectal cancer was evaluated. This
study aims to assess whether there is difference in performance of USPIO-MRI
with good vs bad node-harvesting.
Methods and Materials: 117 primary rectal cancer patients were evaluated retrospectively. All patients underwent USPIO-enhanced MRI followed by TME. An
expert reader predicted nodal status by USPIO-MRI using a confidence level score
(0=definitely N- to 4= definitely N+), with histology as reference standard. Patients
were categorised according to the number of lymph nodes harvested at histology
(group 1=0-4 nodes, 2=4-8 nodes, 3=8-12 nodes, 4=12-16 nodes, 5=16-20 nodes,
6=/= 20 nodes). ROC-curve analyses were performed for the 6 groups.
Results: AUC for group 1 (n=9) was 0.643, for group 2 (n=29) 0.830, for group 3
(n=32) 0.833, for group 4 (n=27) 0.917, for group 5 (n=12) 0.857, and for group
6 (n=8) 1.00.
Conclusion: 1. Diagnostic performance of USPIO-MRI for nodal staging in rectal
cancer increases with increasing number of nodes harvested at histology. 2. Best
MR performance correlates with AUC of groups 4-6, confirming that optimal number
of harvested nodes should be recommended = 12. 3. In case of suboptimal histological nodal staging (4-12 harvested nodes), nodal staging with USPIO-enhanced
MRI would be more reliable for clinical decision making.
B-473
10:48
Accuracy of Gadofosveset-enhanced MRI for predicting nodal status in
primary rectal cancer
D.M.J. Lambregts, G.L. Beets, A.G. Kessels, M.J. Lahaye, S.M.E. Engelen,
M. Maas, A.P. de Bruïne, J.E. Wildberger, R.G.H. Beets-Tan; Maastricht/NL
(d.lambregts@mumc.nl)
Purpose: Nodal involvement indicates poor prognosis in rectal cancer. Accurate
assessment of nodes with MRI could allow tailored treatment according to individual
risk. Our goal was to validate gadolinium-based contrast (Gadofosveset)-enhanced
MRI for prediction of nodal status in primary rectal cancer patients.
Methods and Materials: A total of 32 rectal cancer patients underwent MRI
including T2W FSE (T2W) and Gadofosveset-enhanced T1W GRE. Patients were
stratified into three treatment groups: total mesorectal excision (TME; n = 5), TME
with neoadjuvant radiotherapy (n =1 0) and TME with neoadjuvant chemoradiation (CRT; n = 17). The latter underwent a second MRI post-CRT with additional
assessment thereafter. An experienced reader predicted each node for benign
or malignant on T2W and Gadofosveset-enhanced images respectively using a
confidence level score (0=definitely benign, 1=probably benign, 2=possibly malignant, 3=probably malignant, 4=definitely malignant). Nodes were recorded on an
anatomic map, used as a template for lesion by lesion comparison with histology.
Receiver operator characteristics (ROC) curve-analyses were performed to compare
diagnostic performance.
Results: In 32 patients, 208 nodes were analysed, of which 47 positives in 14
patients. 44/47 positive nodes were predicted correctly on Gadofosveset-enhanced
MRI. Per lesion sensitivity was 93%, specificity 96%, PPV 88% and NPV 98%.
Area under the ROC-curve (AUC) for Gadofosveset-enhanced imaging was better
than for T2W imaging (0.979 vs 0.813, p 0.001). Per patient sensitivity was 93%,
specificity 89%, PPV 87%, NPV 94% and AUC 0.917.
Conclusion: Although larger multicenter studies are needed to confirm our results,
Gadofosveset-enhanced MRI is accurate and promising for prediction of metastatic
nodes in rectal cancer patients.
B-474
10:57
Diffusion-weighted imaging assessment of lymph node metastasis in pelvis
Y. Liang, E. Jin, Y. Zhang, W. He; Beijing/CN (liangyuting688@sina.com.cn)
Purpose: The goal of this study is to compare the routine MRI (T1WI and T2WI)
and combined routine MRI with diffusion-weighted imaging (DWI) in the detection
of lymph node metastasis in pelvis.
Methods and Materials: A total of 53 patients with malignant tumor in pelvis who
underwent MRI for local staging and received radical tumor excision soon after MRI
were enrolled in the study. MRI transverse fat suppression T2WI, T1WI, dynamic
Scientific Sessions
enhanced T1WI and DWI (b = 1000 s/mm2) were performed using a 8-channel coil
at a 3 T in all patients. The scan time of DWI is 1 m and 58 s. Tumor spectrum in
the study included rectal adenocarcinoma (37 patients), rectal lymphoma (1 case),
rectal carcinoid (1 case), prostate adenocarcinoma (9 patients) and endometrial
caner (5 patients). Based on the pathologic result, the ability in the detection of
lymphadenopathy in pelvis was compared between routine MRI sequences and
routine sequences plus DWI.
Results: Pelvis lymph node metastasis was found in 39 patients (73.6%) by pathology from excisional specimen and total 137 lymph nodes ranging from 0.2-1.3 cm
were involved in cancer. Abnormal signal change on DWI was detected within
tumor areas in 50 patients (94.3%). Lymph node metastasis had same signal
change as primary tumor on DWI. The sensitivity and specificity for routine MRI
in the detection of lymph node metastasis were 84 and 65%, while routine MRI
combined DWI were 83 and 81%.
Conclusion: DWI could help to detect the small lymph node metastasis in pelvis.
Routine MRI combined with DWI may increase the accuracy of local tumor stage.
B-475
11:06
Appearance of non-metastatic pelvic lymph nodes at diffusion-weighted
imaging: A quantitative evaluation of apparent diffusion coefficient values
P. Paolantonio1, R. Ferrari1, M. Rengo1, F. Vecchietti1, P. Lucchesi1, F. Vasselli2,
A. Laghi1; 1Latina/IT, 2Rome/IT (paolantoniopasquale@hotmail.com)
B-476
11:15
Diffusion-weighted MRI for the diagnosis of rectal carcinoma: Preliminary
results of a prospective study
G. Engin, R. Sharifov, M. Gulluoglu, Y. Kapran, E. Balik, S. Yamaner; Istanbul/TR
(gengin@istanbul.edu.tr)
Purpose: To evaluate the clinical value of diffusion-weighted magnetic resonance
imaging (DW-MRI) to diagnose the primary carcinoma of rectum by measuring
tumor and normal rectal wall apparent diffusion coefficient (ADC).
Methods and Materials: Thirty-two cases, who had been histopathologically diagnosed as adenocarcinoma were evaluated with MRI prior to the treatment. MRI
was applied with 1.5-Tesla MR (Symhony, Siemens Medical Solutions, Erlangen,
Germany) instrument and pelvic phase array coil. DW-MRI was applied in all patients along with standard TSE imaging. TSE imaging was applied to T1W axial,
T2W axial, sagittal and oblique coronal planes. In DW-MRI, inversion recovery
echo-planar images (“IR” EPG) were obtained. B values were taken as 50, 400,
800 sn/mm² and ADC maps images were obtained. The mean ADC of tumor and
normal appearing rectal wall was obtained using region of interest (“ROI”) in ADC
maps images.
Results: Mean ADC values obtained from rectal tumor and normal appearing
rectal wall were found as 0.77 p 0.14 (range 0.58-1.16) x 10³ mm²/sc ve 1.71 p 0.18
(range 1.31-2.03) x 10³ mm²/sc, respectively. Statistically significant difference was
found between these values (p 0.001). Furthermore, DW-MR images were found
useful in distinguishing tumor from normal rectal wall.
Conclusion: DW-MRI can contribute to TSE imaging in tumor diagnosis and
border determination.
11:24
Evaluation of image quality and CNR values between 1.5 T and 3 T in rectal
cancer
J. Pernas, D. Hernandez, J. Otero, J. Monill, C. Perez, M. Menso; Barcelona/ES
(JOtero@santpau.cat)
Purpose: To compare the results of 1.5 T vs 3 T regarding the overall image quality,
contrast to noise ratio (CNR), normal anatomic structures depiction and tumor and
lymph nodes delineation in patients with rectal neoplasm.
Methods and Materials: 40 patients with proven rectal cancer underwent pelvic
MR. They were randomized 20 at 3.0 T/20 at 1.5T. The pelvis, using superficial coil,
was imaged with T1WI in axial plane and T2WI in axial, coronal and saggital planes
following the same imaging protocol. CNR was measured in T2WI axial at rectal
tumor vs perirectal fat. The images were analysed retrospectively by three independent observers unaware of which MR machine was used. The overall image quality
and other parameters regarding tumor and lymph nodes delineation and normal
anatomic structures were evaluated using a consensuated grade scale (1-5).
Results: Overall image quality was 1.7/5 for the 1.5 T and 3.7/5 for the 3 T. Scale
grade artifact scored 1.8/5 for the 1.5 T and 2.2/5 for the 3 T. Discrimination between
the signal of the tumor vs normal rectal wall scored 1.9/5 for the 1.5 T and 3/5 for
the 3 T. Lymph nodes delineation scored 1.8/5 for the 1.5 T and 2.1/5 for the 3 T.
CNR was 35.3 for the 1.5 T and 49.09 for the 3 T.
Conclusion: 3 T obtained better overall image quality than 1.5 T in the depiction
of the tumor, although a higher number of artifacts in the upper part of the pelvis
were found in the 3 TMR. No significant differences were found regarding tumor and
lymph nodes delineation, normal anatomic structures depiction and CNR.
B-478
11:33
Whole-body MRI at 1.5 and 3 Tesla compared to FDG-PET-CT for the
detection of tumor recurrence in patients with colorectal cancer
G.P. Schmidt, A. Baur-Melnyk, J. Lutz, A. Haug, C.R. Becker, M.F. Reiser,
K.A. Herrmann; Munich/DE (gerwin.schmidt@med.uni-muenchen.de)
Purpose: To assess the diagnostic accuracy of whole body-MRI (WB-MRI) at 1.5
and 3 Tesla compared to FDG-PET-CT in the follow-up of patients suffering from
colorectal cancer.
Methods and Materials: 24 patients with a history of colorectal cancer and suspicion of tumor recurrence underwent FDG-PET-CT and WB-MRI at 1.5 (n=14)
or 3 Tesla (n=10). Coronal T1w-TSE- and STIR-sequences at four body levels,
HASTE-imaging of the lungs, T2w-TSE and contrast-enhanced T1w-sequences
of the liver, brain, abdomen and pelvis were performed. Local recurrence, lymph
node involvement and distant metastatic disease were assessed using radiological
follow-up within 6 months as standard of reference.
Results: 77 malignant foci in 17/24 patients were detected with WB-MRI and PETCT. Both modalities concordantly revealed 2 local recurrent tumors. PET-CT detected
more lymph node metastases (sensitivity 93%, n=27/29) than WB-MRI (sensitivity
63%, n=18/29). PET-CT and WB-MRI achieved similar sensitivity for the detection
of organ metastases with 80 and 78% (37/46 and 36/46). WB-MRI detected brain
metastases in 1 patient, 1 false-positive local recurrence was indicated by PET-CT.
Overall diagnostic accuracy for PET-CT was 91 and 83% for WB-MRI. Examination
time for WB-MRI at 1.5 and 3 T was 52 and 43 min.
Conclusion: FDG-PET-CT is the method of choice for integrated tumor imaging
in the follow-up of colorectal cancer, especially for the diagnosis of lymph node
metastases. WB-MRI is useful for the detection of organ metastases, especially to
the liver, bone and brain. WB-MRI at 3 Tesla is feasible and provides overall scan
time reduction at constant image resolution.
B-479
11:42
Rectal carcinoma: MR imaging features with pathologic correlation before
and after chemoradiation therapy
V. Di Giacomo, R. Del Vescovo, I. Sansoni, L. Trodella, R. Grasso, L. Trodella,
B. Beomonte Zobel; Rome/IT
Purpose: To evaluate the extent and imaging appearance of rectal carcinoma
before and after chemoradiation therapy using magnetic resonance imaging and
to correlate the post-treatment MR imaging appearance with pathologic findings
after surgical excision.
Methods and Materials: A preoperative MRI in 20 patients with locally advanced
adenocarcinoma of rectum was performed before and after a 5-week course of
chemoradiation therapy. The protocol included turbo spin-echo T2-weighted MR
imaging and spin-echo T1-weighted MR imaging with and without fat suppression.
Post contrast T1-weighted sequences with fat suppression were also employed.
Primary tumor and nodal involvement were evaluated by preoperative MR before
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Purpose: To evaluate the appearance and conspicutity of non-metastatic pelvic
lymph nodes at diffusion-weighted imaging (DWI) and to assess the range of apparent diffusion coefficient (ADC) values in healthy volunteers.
Methods and Materials: A total of 40 healthy volunteers ranging in age between
23 and 45 years were included. All subjects underwent MR scan of the pelvis on a
1.5 T MR platform (Signa Hde; GE, USA). A TSE T2W sequence (TR: 4,500 msec;
TE: 190 msec; matrix: 512 x 256; slice thickness 4 mm; Nex 4) and an SE-EPI-DWI
sequence (TR 9,000 msec; TE: 87 msec; matrix 128 x 128; Fov 350 x 350 mm; slice
thickness 5 mm; Nex 8 acq. time: 2 min 50 sec; b values: 0-1000) were acquired;
ADC values were calculated on a per pixel basis. Image analysis was performed
by two radiologists in consensus. A node-by-node matching comparison was
performed between TSE T2W and b-1000 DW images. CNR between lymph node
and adipose tissue on both TSE T2W images and b 100DW were compared using
non-parametric Wilcoxon test (P 0.0001). For each node, the ADC value was
measured using an ROI.
Results: A total of 423 lymph nodes were recognized with minimum diameter ranging between 3.5 and 9.5 mm. A node-by-node matching between DWI sequence
and TSE T2W images was possible for each lymph node. Lymph node CNR was
significantly higher on heavy DWI with respect to TSE T2W images. The values of
ADC were as follows: mean, 2.01 (DS 0.3) x 10-3 mm2/sec.
Conclusion: Non-metastatic lymph nodes show high signal intensity on heavy
DW images and are clearly identifiable, thanks to high conspicuity, with respect
to surrounding tissues and structures. Mean ADC value of non-metastatic lymph
node in our series was 2.01 (DS 0.3) x 10-3 mm2/sec.
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and after chemoradiation therapy: morphologic changes and nodal downstaging
were recorded. Pathologic findings of resected tumors were compared to posttreatment MR imaging appearance to evaluate the accuracy of MR in the prediction
of tumor stage, nodal downstaging and distance between tumor and circumferential
resection margin.
Results: Tumor shrinkage 30% was found in 10 (53%; 90% CI, 56-70%) of 20
patients; changes in MRI T stage occurred in 6 (15%; 90% CI, 5-25%) of 20 patients.
All cases of tumor regression from the circumferential resection margin were found
and confirmed at histologic examination. Nodal downstaging was observed in 10
(67%; 89% CI, 50-79%) of 17 patients.
Conclusion: Our results suggest that MR imaging could be a useful diagnostic tool
in the preoperative assessment of tumor size and nodal downstaging after chemoradiation therapy in patients with rectal carcinoma. The distance between tumor and
circumferential resection margin can be assessed by MR with good accuracy.
B-480
11:51
Can magnetic resonance imaging detect complete response after
downsizing chemoradiotherapy for rectal cancer?
M. Anderson, M. Betts, A. Slater, F.V. Gleeson; Oxford/UK
(eanderson@doctors.org.uk)
Purpose: To evaluate the utility of MRI to detect complete tumour response and
differentiate from other responses.
Methods and Materials: 30 patients with rectal cancer treated by downsizing CRT
were selected from a pathological database to include approximately half complete
or near (T2) complete response. Imaging was carried out on a 1.5 T scanner. Two
experienced observers reported the studies independently. The tumour and nodal
status was assessed. Response to chemotherapy was assessed on a five point
scale, from disease progression to complete response. Histopathology was used
as the reference standard. Sensitivity, specificity and accuracy were calculated.
The agreement between radiological response and pathology was assessed with
Cohen’s Kappa.
Results: After CRT, there was T0 tumour in 23% (n=7/30) and T2 tumour in 20%
(n=6/30). From comparison of pretreatment scan to pathology 26% (n=8/30) showed
no response and 10% (n=3/30) had progressed. The sensitivity and specificity and
accuracy for detecting T0 was 55, 76 and 70%, respectively, for observer 1 and
33, 62 and 33% for observer 2. Whilst there was excellent agreement between the
observers for the T staging, kappa= 0.602, the agreement of each observer with
pathology was poor, k= 0.31 and 0.27. There was good agreement in the assessment
of progression, stable disease or partial response, with k= 0.5 and 0.56.
Conclusion: MRI is unable to reliably detect T0 post CRT and cannot consistently
distinguish this from T2 tumours. It is able to more accurately detect disease progression, stable disease or partial response.
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Room F1
Genitourinary
SS 1007
Imaging of prostate cancer
Moderators:
L. Pallwein; Innsbruck/AT
A. Zubarev; Moscow/RU
B-481
10:30
Multimodality imaging of prostate cancer
J. Grimm, V. Ponomarev, P. Gregor, P. Brader, H. Hricak; New York, NY/US
(grimmj@mskcc.org)
Purpose: Prostate-specific membrane antigen (PSMA) is expressed on prostate
cancer cells and correlating with disease aggressiveness. This antigen evoked
interest as predictor for progression of prostate cancer since highest levels are
seen in metastatic and higher-grade disease. Imaging of PSMA could therefore be
very useful in detection and characterization of prostate cancer. For this purpose,
we developed probes for multimodality imaging of PSMA.
Methods and Materials: In silico modeling of phage-derived peptides binding to
PSMA was performed to evaluate binding. Peptides were attached to magnetofluorescent nanoparticles. Binding to PSMA-expressing cells (LNCAP) was evaluated
utilizing FACS. Mice bearing LNCAP and PC3 (PSMA-negative) tumors were
injected with probe. Optical tomography and MR imaging was performed 24 hours
later. A nonspecific intravascular optical probe (Angiosense, VISEN) was used to
normalize for tumor vascularity.
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Results: Specific binding of the peptide was confirmed by incubating FITC-labeled
peptide with LNCAP or PC3 cells at various concentrations. Increasing binding to
LNCAP cells was observed with rising peptide concentration while binding to PC3
cells never exceeded the background. In vivo optical imaging revealed 8-times
higher binding to the PSMA-expressing tumor as compared to control tumor. On
MRI the T2 relaxation time was markedly lower in the PSMA-expressing tumor
(DT2 of 28p9 ms). Histology confirmed the targeting of the particles to the PSMAexpressing tumor cells.
Conclusion: A nanocompound probe for multimodality imaging of prostate cancer
was developed. This probe allowed specific detection of PSMA-expressing tumors
in vitro and in vivo and can be utilized to further characterize prostate cancer.
B-482
10:39
Detection of prostate cancer with contrast-enhanced ultrasonographic
micro-flow imaging: Comparison with conventional ultrasonography
F. Li, S. Xie, J. Xia, J. Du, H. Li; Shanghai/CN
Purpose: To evaluate the value of contrast-enhanced ultrasonography in detecting prostate cancer using micro-flow imaging (MFI) compared with conventional
ultrasonography.
Methods and Materials: A total of 65 patients with serum prostate- specific antigen
levels higher than 4.00 ng/ml (4.01-86.94) were evaluated with transrectal grayscale, power Doppler, MFI ultrasonography examinations and then sonographically
guided biopsy. MFI was performed using contrast agent SonoVue. Biopsy was
performed at 12 sites of the base, the mid gland and the apex in each patient.
When any of the three methods showed abnormality, the biopsy site was directed
to the abnormal foci. Diagnostic efficiency of the three methods for prostate cancer
detection was compared based on biopsy results according to the patient and
biopsy site.
Results: Overall, prostate cancer was detected in 230 (29.4%) of 780 specimens
in 36 (55.3%) of 65 patients. MFI could detect more patients than gray-scale and
power Doppler (P = 0.021 and P = 0.031, respectively); 6 (16.7%) of the 36 patients
diagnosed with cancer were identified only by MFI. Based on the biopsy site, MFI
had higher sensitivity and overall accuracy (80.0 and 83.1%) than gray-scale (46.9
and 76.8%) and power Doppler (37.4 and 74.6%) ultrasonography (P = 0.004 and
P 0.001, respectively; P = 0.001 and P 0.001, respectively), while the specificity
of MFI was 84.3%, lower than 89.3% for gray-scale and 90.2% for power Doppler
ultrasonography (P = 0.004 and P 0.001, respectively).
Conclusion: Based on the biopsy site, MFI could detect more prostate cancer
patients and improve sensitivity and overall accuracy than conventional ultrasonography.
B-483
10:48
Usefulness of a 3D T2-weighted turbo-spin-echosequence (VISTA) at 3
Tesla for a complete morphologic assessment of prostatic carcinoma:
One-stop shop study
C. Roy, A. Matau, G. Bierry, T. Charles, H. Lang; Strasbourg/FR
(Catherine.Roy@chru-strasbourg.fr)
Purpose: To prospectively evaluate 3D T2wTSE sequence (VISTA) by comparison
with multiple 2D T2w-T1w TSE for a complete morphologic prostatic carcinoma
assessment.
Methods and Materials: A total of 47 patients were examined for prostatic
carcinoma staging at 3.0 T (Achieva, Philips) with a standard set including three
orientations 2D T2wTSE (4,862 ms/80 ms, endorectal coil, 0.6 × 0.7 × 3.00 mm3,
4:42 min; axial T1wTSE (5 mm, 3:30 min) and 3DTSE (VISTA) TR/TE/FA :
2,113/200/120, 0.9 × 0.9 × 1.1 mm3, 4 : 58 min pelvic coil). Fat, peripheral zone,
tumor SNR, as well as tumor-peripheral zone CNR were measured from ROI. Two
radiologists correlated 3D VISTA with 2D rated image quality with contrast-ratio
impression, signal homogeneity and artefacts, as well as prostatic capsule and
lymph node visualization.
Results: Fat, peripheral zone, capsule SNR and tumor-peripheral zone CNR were
higher with 3D VISTA (774, 845, 168, 655 p 11) compared with 2DTSE (627, 490,
136, 446 p 15), respectively. Higher contrast images provided a perfect visualization
of the prostatic capsule. Image quality, CNR and homogeneity of transverse,coronal
and oblique orientations rated higher for VISTA than for 2D, but lower for the sagittal
view (P 0.05). Minor flow artefacts did not alter the diagnostic confidence. Lymph
nodes assessment was clearly better for shape and vessels differentiation. Interactive 3D MPR software toll providing multiplanar views was essential.
Conclusion: At 3 T, a unique VISTA sequence with wide coverage and high contrast
multiplanar images makes a confident evaluation of tumor-prostatic capsule, as well
as survey of lymph nodes. It makes multiple 2D acquisitions unnecessary.
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B-484
10:57
Predictive value of digital rectal examination, prostate-specific antigen
and combined MRI and MR spectroscopy of the prostate for results of
subsequent biopsy in patients with previously negative prostate biopsy
U.G. Mueller-Lisse, U.L. Mueller-Lisse, M. Seitz, C. Stief, M.F. Reiser,
M.K. Scherr; Munich/DE (muellerlisse@aol.com)
Purpose: To assess predictive values for results of subsequent prostate biopsy of
combined MRI and MR spectroscopy of the prostate (MRI + MRS), digital rectal
examination (DRE), and prostate-specific antigen (PSA) in patients with suspected
prostate cancer (PCA) and previously negative prostate biopsy (pnpbx).
Methods and Materials: Among 499 patients who underwent MRI + MRS with
an endorectal-coil-body-phased-array-coil system at 1.5 T between 05/2003 and
04/2007, cases with suspicion of PCA at DRE or PSA ( 4 ng/ml), no previous
treatment, pnpbx, and subsequent prostate biopsy in our institution were retrospectively analyzed.
Results: Among 42 patients (age, 64p6 years, PSA 11.0p6.7 ng/ml, 2p1 pnpbx),
subsequent prostate biopsy revealed PCA in 12 (29%, Gleason sum, 6p1). Respective positive and negative predictive values for PCA at subsequent biopsy were
6/14 (43%) and 22/28 (79%) for DRE, 6/18 (33%) and 18/24 (75%) for PSA (cut-off,
10 ng/ml), 12/32 (38%) and 10/10 (100%) for MRI + MRS, and 11/14 (79%) and
27/28 (96%) for MRI + MRS with signs of PCA in the peripheral zone of more than
one half prostate sextant.
Conclusion: After negative prostate biopsy, MRI + MRS may detect both patients
who would not benefit from another biopsy and patients whose next biopsy is
highly likely to show PCA.
B-485
11:06
Assessing combination of diffusion coefficients, metabolic profiles
and vascular maps on magnetic resonance imaging for prostate cancer
detection
S.F. Riches1, V.A. Morgan1, S. Sandhu1, C. Fisher2, G.S. Payne1, M. Germuska1,
D.J. Collins1, A. Thompson2, N.M. deSouza1; 1Sutton Surrey/UK, 2London/UK
(Nandita.Desouza@icr.ac.uk)
B-486
11:15
Improved detection of prostate carcinoma by integration of six different
MR methodologies at 1.5 T
K. Engelhard1, H.-P. Hollenbach2, D. Engehausen1; 1Nürnberg/DE, 2Erlangen/DE
(k.engelhard@martha-maria.de)
Purpose: To determine the diagnostic valency of an optimized diagnostic MRprogram in detecting prostate cancer.
Methods and Materials: 24 patients with elevated PSA levels (PSA 4 ng/ml)
underwent endorectal MRI in a 1.5 T scanner (Magnetom Espree, Siemens Medical
Solution Erlangen, Germany). Six different imaging techniques were applied. The
program comprised T2-weighted (T2w) protocols, T2/T2*-mapping protocols, a EP-
B-487
11:24
Clinical significance of endorectal MR in prostate cancer patients for nerve
sparing radical prostatectomy: Retrospective analysis in 386 patients
H.-P. Schlemmer, M. Mlynczak, M. Rothke, M.P. Lichy, U. Vogel, D. Schilling,
A. Stenzl, C.D. Claussen; Tübingen/DE
Purpose: To evaluate the clinical significance of standardized high-spatial resolution
T2w endorectal MRI in patients with prostate cancer for planning nerve sparing
radical prostatectomy.
Methods and Materials: In total, 386 patients with biopsy-proven prostate cancer
(mean age 62.7 years) were included who all underwent standardized endorectal
MRI before radical prostatectomy (mean time interval 13 days). MR examinations were performed at 1.5 T using a commercial available endorectal and body
phased array coil. Standardized high-resolution transverse and coronal T2w TSE
sequences were applied and evaluated by experienced radiologists in clinical
routine applying conventional imaging criteria. Radiological and histopathological reports were retrospectively compared and analysed including data of PSA,
Gleason score and grading.
Results: Mean value of PSA serum level was 8.9 ng/ml, pathologic Gleason
Score 6.7 and of Grading 2.3. Organ-confined disease was found by pathology in
267 patients (69%). In total, 82% of these patients had multifocal tumors involving
both lobes (stage T2c). Nerve sparing for at least on side of the prostate could be
achieved in 78% of the patients. Positive predictive value of MR for organ-confined
disease (extracapsular extension) was 78% (71%). Bilateral (unilateral) nerve
sparing was achieved in 46% (32%) of the patients in case when MR described
organ-confined disease whereas in 31% (46%) of the patients when MR discribed
extracapsular extension.
Conclusion: Most of surgical candidates present with multifocal tumors involving
both lobes of the prostate. Endorectal MRI is an useful predictor for extracapsular
tumor extension and positively influences the success of bilateral nerve-sparing
surgery.
B-488
11:33
Contrast-enhanced colour Doppler-targeted prostate biopsy for prostate
cancer detection: Results of 2,008 men
L. Pallwein, F. Aigner, W. Jaschke, V. Spiss, M. Mitterberger, F. Frauscher;
Innsbruck/AT
Purpose: To compare the prostate cancer detection rate of contrast-enhanced
colour Doppler ultrasound-targeted biopsy with grayscale US-guided systematic
biopsy in a series of 2,008 men.
Methods and Materials: In a 4-year period, 2,008 male screening volunteers with
a total prostate-specific antigen of 1.25 ng./ml. or greater and free-to-total prostatespecific antigen less than 18% were included. Mean patient age was 60 +- 9.3 years
and mean PSA value was 6.5 +- 14.7 ng/ml. Two independent examiners evaluated
each patient and a single investigator performed five or fewer contrast-enhanced
targeted biopsies into the hypervascular regions in the peripheral zone during
intravenous infusion of the US contrast agent SonoVue. Subsequently, another
examiner performed ten systematic prostate biopsies. The cancer detection rates
of the two techniques were compared.
Results: Overall, cancer was detected in 559 patients (28%), including 476 (24%) by
contrast-enhanced targeted biopsy and in 410 (20%) by systematic biopsy. Cancer
was detected by targeted biopsy alone in 149 patients (27%) and by systematic
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Purpose: To compare diffusion, metabolic and vascular characteristics in histologically-defined prostate tumour with non-tumour and determine which parameters
detect tumour most accurately.
Methods and Materials: Twenty patients due for prostatectomy underwent endorectal MRI at 1.5 T. Transverse T2-W, diffusion-weighted, 2-D chemical shift and
dynamic contrast-enhanced images were acquired. At prostatectomy, transversely
sectioned fresh slices and stained whole-mounts with histologically-defined tumour
outlines were photographed. These tumour regions (TU) were mapped to the corresponding T2-W image and apparent diffusion coefficients (ADC), choline/citrate
ratios (Cho/Cit) and vascularity obtained for TU, normal peripheral zone (PZ) and
central gland (CG). ROC curves determined the combination of parameters with
highest sensitivity and specificity for prostate cancer detection.
Results: In TU= 1 cm2, ADC and Cho/Cit were significantly different compared with
non-TU PZ+CG (p=0.003), PZ alone (p 0.001) and CG alone (p=0.046). TU vascularity was increased in TU compared with PZ+CG (initial area under the gadolinium
curve (IAUGC):p=0.012, forward rate constant (Ktrans):p=0.011, return rate constant
(Kep):p=0.036 and PZ alone (IAUGC:p=0.007, Ktrans:p 0.001, Kep:p=0.011) but not
CG. Combined ADC and IAUGC were significantly better than either parameter
alone (p = 0.001), combined ADC and Cho/Cit was significantly better than ADC
(p=0.001) but not Cho/Cit (p=0.175) and combined Cho/Cit and IAUGC was significantly better than IAUGC (p 0.001) but not Cho/Cit alone (p=0.338). All three
parameters together did not improve sensitivity and specificity further.
Conclusion: Combination of any two functional parameters provides highest sensitivity and specificity for prostate cancer detection and is significantly better than
any technique alone. Using a third parameter does not improve this further.
based diffusion weighted-imaging (DWI) protocol (b-values:50,400,800) including
a calculated apparent diffusion coefficient map (ADC), a 3D-T2w SPACE protocol,
a 3D-CSI spectroscopy protocol and a dynamic contrast enhanced imaging (DCE)
protocol based on a 3D-GRE-sequence (VIBE). The diagnosis was confirmed by
TRUS-guided biopsy in 20 patients and MRI-guided biopsy in 4 cases by performing
8 biopsy cores in each patient. The examination time was 75 minutes.
Results: Cancer was found in 13 cases at histology, 11 patients showed benign
conditions as benign prostate hyperplasia (BPH) and chronic prostatitis. For cancer
detection the combination of T2w-, diffusion-, spectroscopic- and T2-mappingimaging yielded the highest sensitivity. A lower sensitivity, but a higher specificity
in cancer depiction could be evaluated by adding T2/T2*-mapping, spectroscopicand DCE-imaging to T2w-imaging protocols. When all six imaging modalities were
applied, a sensitivity of 86% and a specificity of 90% in tumor detection could be
achieved.
Conclusion: The demonstrated MR protocol integrating six different MR methodologies can improve prostate cancer detection and raise the probability of further
tumor negative biopsy results but is time consuming. The method can be a valuable
instrument for selecting candidates either for a repeated prostate biopsy or PSA
controlled watchful waiting.
Scientific Sessions
biopsy alone in 83 (15%). The detection rate for targeted biopsy cores (10.8% or
961 of 8,880 cores) was significantly better than for systematic biopsy cores (4.5%
or 923 of 20,080 cores, P 0.001).
Conclusion: These largest data in literature show that contrast-enhanced colour
Doppler-targeted prostate biopsy is superior to systematic prostate biopsy in a
screening population.
10:30 - 12:00
B-489
Moderators:
W. Buchberger; Innsbruck/AT
M. Mellado; Pamplona/ES
11:42
Prospective randomised control trial: Impact of combined un-enhanced
and dynamic contrast-enhanced MRI prior to TRUS biopsy in patients
being investigated for a raised PSA
J.T. Smith, B. Crabtree, S. Bacon, D. Wilson, P. Harnden, B. Carey; Leeds/UK
(drjontsmith@aol.com)
Purpose: Straight to biopsy is currently the gold standard in investigating patients
with a raised PSA. As PSA is not specifically raised in patients with prostate cancer,
the majority of biopsies do not identify adenocarcinoma. We set out to investigate
whether CEMRI in addition to T2W imaging prior to biopsy increased the cancer
diagnostic yield.
Methods and Materials: Local ethics approval was obtained. 40 consecutive unselected patients referred for biopsy were randomised to either straight to biopsy
(control arm) or CEMRI + T2W prostate imaging prior to biopsy (interventional
arm).
Results: Both control and interventional arms were equally represented with 20
patients. Mean age, PSA and size of gland were 65 years, 11 ng/L and 57 cc in the
control arm and 67 years, 11 ng/L and 66 cc in the interventional arm. 6 patients in
the control arm and 5 patients in the interventional arm were found to have cancer.
In the control arm: 162/171 (95%) were untargeted biopsies and 9/171 (5%) targeted
biopsies. 16/162 (10%) of the untargeted biopsies were positive for cancer and 3/9
(33%) targeted biopsies were positive for cancer. In the interventional arm: 144/170
(85%) were untargeted biopsies and 26/170 (15%) were targeted biopsies. 15/144
(10%) of the untargeted biopsies were positive for cancer and 6/26 (23%) targeted
biopsies were positive for cancer.
Conclusion: There is no value in using CEMRI plus T2W imaging prior to prostate
biopsy in unselected patients being investigated for a raised PSA.
B-490
11:51
Dynamic-contrast-enhanced MRI and MR-guided biopsy in the detection of
local recurrence after radiation therapy for prostate cancer
D. Yakar, T. Hambrock, J.J. Fütterer, H. Huisman, E. van Lin, J.O. Barentsz;
Nijmegen/NL (d.yakar@rad.umcn.nl)
Purpose: To assess the potential value of 3 T MR-guided biopsy of tumor suspicious
regions (TSR) on 3 T dynamic-contrast-enhanced (DCE) MRI to detect prostate
cancer recurrence following radiotherapy.
Methods and Materials: In this pilot study, 17 patients with prostate cancer previously treated with radiotherapy ( 1 year before) underwent an endorectal coil
3 T MRI (Siemens, Trio Tim, Germany) following three consecutive rises in PSA.
Two radiologists in consensus determined the TSR from DCE-MR images. An MR
biopsy device (Invivo, Germany) was used in conjunction with a phased array coil
to perform prostate biopsies under 3 T MR guidance. Anatomical landmarks and
features on T2-weighted turbo spin echo and TRUE-FISP images were used to
translate prior-determined TSR for biopsy. A total of 14 patients received MR-guided
biopsies, while 3, due to evidence of metastatic disease, did not.
Results: The average duration of MR-guided biopsies was 30 min. In total, 50
biopsy cores of 27 different TSR were obtained. The median number of cores taken
per patient was 3 (range 2-5). Prostate cancer was found in 12/14 (86%) patients
and 20/27 (positive predictive value of 74%) were positive for tumor on biopsy. One
TSR contained normal tissue, one TSR contained residual tumor with radiotherapy
effects, while 5/27 of the remaining TSR contained radiotherapy-induced reactive
atypia. No procedure-related complications occured.
Conclusion: This pilot study shows that 3 T MR-guided biopsy of TSR on 3 T
DCE-MRI has a potential value in improving the detection of local prostate cancer
recurrence following radiotherapy.
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Room F2
Breast
SS 1002
US and follow-up after surgery
B-491
10:30
The role of second-look ultrasound in evaluating suspicious breast MRI
lesions
A. Russo, G. Carbognin, C. Calciolari, V. Girardi, R. Pozzi Mucelli; Verona/IT
(annar1979@libero.it)
Purpose: To estimate the value of second-look US detection of suspicious lesions
diagnosed by contrast-enhanced breast MRI.
Methods and Materials: We reviewed the final reports of 498 MRI. Recommendations for second look were given in 50 patients (10%), who underwent MRI for
preoperative staging of known cancer (36), scar tissue evaluation (7), studying
equivocal mammographic-ultrasound findings (3), monitoring response to neoadjuvant chemiotherapy (1), screening in women with familial cancer (1) and studying
breast implants (2). We tabulated the results of subsequent US, pathologic diagnoses from surgery and from biopsies performed after second look.
Results: Of 50, 36 (72%) additional MRI lesions were identified by second look.
Biopsies were carried out in 25/36 patients with US findings: 10 were shown to be
positive for malignant lesion (27% of sonographic findings). Of 50, 14 (28%) were
not identified by second look. Surgery was carried out for 4/14 with no US findings
and MR guided-biopsy in 1/14:4 was shown to be positive for additional malignant
lesion (28% of sonographic occult findings), (two of category 4 and two of category
5 according to MRI BI-RADS).
Conclusion: There are no differences in the rates of malignancy for suspicious
MRI lesions, US detected (27.7%) and US occult (28.5%) at second look. Given the
benefits of US-guided biopsy, second-look US is a reasonable initial approach, but
the lack of US detection does not negate the need for biopsy of suspicious MRI lesions, especially considering our study population and MRI BI-RADS categories.
B-492
10:39
The challenge of imaging dense breast parenchyma: Is MR mammography
the technique of choice? A comparative study with X-ray mammography
and ultrasound
S. Cagioli, F. Pediconi, A. Roselli, V. Dominelli, M.L. Luciani, V. Casali,
C. Catalano, R. Passariello; Rome/IT (sabrinacagioli@gmail.com)
Purpose: To establish the value of magnetic resonance imaging (MRI) of the breast
relative to X-ray mammography and ultrasound for breast cancer evaluation in
women with dense breast parenchyma.
Methods and Materials: A total of 238 women with dense breast parenchyma
(BI-RADS 3 or 4) who were suspicious for breast cancer or inconclusive for the
presence of breast lesions based on clinical examination, ultrasound or X-ray mammography and who underwent breast MRI at 1.5 T before and after administration
of 0.1 mmol/kg gadobenate dimeglumine were evaluated. Lesions considered
malignant on breast MRI (BI-RADS 4 or 5) were evaluated histologically; the final
diagnosis of other patients was based on a 12-18-month follow-up. The diagnostic
performance (sensitivity, specificity, accuracy and positive and negative predictive
values) of each technique was determined and compared (chi-square test).
Results: At final diagnosis, 121/238 (50.8%) women had confirmed malignant lesions, whereas 117 (49.2%) had benign or no lesions. Significantly (P 0.015) better
diagnostic performance was achieved with breast MRI (diagnostic accuracy 95.4
vs. 57.2% for X-ray mammography and 72.3% for ultrasound). Among 97 women
who underwent all three techniques, more lesions were detected with breast MRI
(n = 135) than with X-ray mammography (n = 85) and ultrasound (n = 107) and the
diagnostic confidence was greater. Breast MRI detected more cases of multifocal,
multicentric and contralateral disease and fewer misdiagnoses occurred.
Conclusion: Breast MRI is more effective than X-ray mammography and ultrasound
for the detection of breast cancer in women with dense breast parenchyma.
Scientific Sessions
B-493
10:48
The value of second look ultrasound as a confirmatory method for
incidental enhancing lesions found on breast MRI
F. Pediconi, A. Roselli, V. Dominelli, S. Cagioli, M.L. Luciani, V. Martino,
C. Catalano, R. Passariello; Rome/IT
Purpose: To evaluate the role of second look high-resolution ultrasound for the
identification of incidental enhancing lesions detected on preoperative breast MRI
that have no X-ray mammographic or palpable correlate.
Methods and Materials: Between January 2004 and March 2006, 182 patients
with confirmed breast cancer based on conventional X-ray mammography or US
underwent breast MRI with 0.1 mmol/kg gadobenate dimeglumine for breast cancer staging. Patients with incidental lesions on breast MRI underwent a second
look high-resolution US examination directed at the site of the incidental finding.
Comparison between the two imaging modalities was performed.
Results: Breast MRI detected 55 additional enhancing lesions in 46/182 patients
that were not seen on X-ray mammography or first look US. Of these 55 additional
lesions, 43 corresponding lesions were detected on second look US. US-guided
biopsy or US-guided wire localisation followed by excisional biopsy subsequently
confirmed that 19 of these 43 lesions were malignant. Treatment planning was
altered for four patients with multicentric cancer and seven patients with multifocal
cancer based on combined breast MRI and US findings. The 12 lesions detected
on CE-MRM for which a corresponding lesion was not detected on second look US
were evaluated on MR-guided biopsy or re-assessed by CE-MRM after 3 months.
One of these 12 lesions was confirmed as malignant.
Conclusion: Direct second look US is a confirmatory method for incidental findings
in breast MRI. The likelihood of carcinoma is higher for lesions with a US correlate
than for lesions without a US correlate.
B-494
10:57
Purpose: To determine the performance of an additional ultrasound examination to
mammography in case of breast density ACR 3 and 4 in symptomatic or women at
risk. All patients were examined in the project “quality assurance in breast cancer
diagnosis” (the QuaMaDi Project). In Schleswig-Holstein/Germany this processorientated and comprehensive quality management project was implemented to
improve the standard of breast cancer diagnosis.
Methods and Materials: A prospective cohort between 2001 and 2005 with a total
of 59,514 patients and 102,744 mammograms was initiated. Breast ultrasound
was indicated in all women with ACR III and IV, in addition to a suspicious clinical
examination and in cases of masses in mammography. Abnormalities were defined
positive if biopsy findings revealed malignancy, and negative if biopsy findings or
all examinations turned out to be benign.
Results: Overall 116 mammographically occult breast cancers were diagnosed by
ultrasound out of 62,006 cases (1.9/1000 examinations). Additionally, 12.8% breast
cancers were detected by mammography + US (1019 cancers) vs mammography
alone (903 cancers). In group ACR III/IV supplementary 15.9% cancers were found
by additional US than mammography alone.
Conclusion: Supplementary US to mammography vs mammography alone
resulted in a significant breast cancer detection rate increase of 15.9% in case
of ACR 3 and 4.
B-495
11:06
Real-time virtual sonography improves localization of suspicious lesions
on breast MRI at second-look sonography
S. Nakano, K. Fujii, K. Yorozuya, M. Yoshida, T. Fukutomi, T. Ishiguchi; Aichi-gun/JP
(snakano1@aichi-med-u.ac.jp)
Purpose: To assess the value of real-time virtual sonography (RVS) for localization
of suspicious lesions on breast MRI.
Methods and Materials: A total of 92 patients underwent breast MR, 55 patients
for staging of known breast cancer, and 37 patients for including abnormal findings on conventional images. All the patients were examined using MMG, US,
and RVS enabling both US and MRI cutaway images of the same site, displaying
these images in real time. Breast MR images were obtained on a 1.5-T imager in
the supine position using a flexible body surface coil.
Results: A total of 119 lesions were evaluated with RVS at diagnosis and before
surgery. The overall sensitivity for detecting primary breast tumors was 74%
B-496
11:15
Can microvascular imaging of breast lesions using microbubbles
accurately distinguish benign from malignant lesions?
P.G. Sorelli, D.O. Cosgrove, W. Svensson, N. Zaman, K. Satchithananda,
N.K. Barrett, A.K. Lim; London/UK (paolosorelli@hotmail.com)
Purpose: Fundamental and Doppler imaging of solid breast masses cannot accurately distinguish malignant from benign lesions. We investigate whether microvascular enhancement with ultrasound imaging can aid in distinguishing between
benign and malignant lesions and correlate these findings with histology.
Methods and Materials: 15 patients were recruited from Rapid Diagnostic clinics
with palpable breast lumps. Following informed consent, 5 mls of the microbubble
SonoVue were injected intravenously. Digital clips of the enhancement of the lesion
were obtained using a high frequency, low mechanical index specialised bubble
mode using a 7.5 MHz probe. Clips were reviewed by an experienced Consultant radiologist who scored each lesion on the following characteristics: benign
vs malignant, homogeneous vs heterogeneous enhancement, the presence or
absence of focal defects, well vs ill-defined structure and vascular morphology
score (VMS). Statistical analysis was carried out using the Mann Whitney U and
Chisquare tests.
Results: 15 solitary lesions were examined. 7 were malignant and 8 benign histologically. 8 patients underwent surgery, 3 core biopsy and 4 fine needle aspiration
(FNA). The calculated sensitivity for the procedure was 100%, with 37.5% specificity.
The overall mean VMS and mean VMS for localisation, vessel pattern and density
were higher in the malignant lesions compared to the benign lesions.
Conclusion: The results of our study have not shown any additional benefit in
the use of contrast enhanced ultrasound over conventional triple assessment.
The positive trend seen in the higher mean VMS for the malignant tumours needs
further investigation with a larger cohort of patients.
B-497
11:24
Ultrasound of the surgical specimen in early stage breast cancers:
Accuracy in the evaluation of resection margins
V. Londero, A. Linda, C. Zuiani, M. Panozzo, R. Fazzin, M. Bazzocchi; Udine/IT
(londero.viviana@aoud.sanita.fvg.it)
Purpose: To evaluate the accuracy of the US surgical specimen in the assessment
of the status of resection margins after breast-conserving surgery.
Methods and Materials: Sonographic examination of 29 surgical specimens
of US-detectable malignant tumors was performed. Distance of the lesion from
the specimen margins in radial directions was measured and compared with the
distances measured on pathologic examination. Positive pathologic margins were
defined when invasive or intraductal carcinoma was found within 2 mm of the
specimen margin. Sensitivity, specificity, positive (PPV) and negative predictive
values (NPV) of US were calculated considering a 10-mm and 4-mm cut-off for
the assessment of margins’ status.
Results: The median sonographic size of neoplasms was 12 mm (6-35 mm). Of
116 margins (4 per lesion), pathology demonstrated 18 positive and 98 negative
margins. Considering the 10-mm cut-off, US identified 17 positive and 99 negative
margins, showing sensitivity, specificity, PPV and NPV of 22.2%, 86.7%, 23.5% and
85.8%, respectively. Considering the 4-mm cut-off, US identified 3 positive and 113
negative margins with a sensitivity of 11.1%, specificity of 98.9%, PPV of 66.7%
and NPV of 85.8%. False-negative results were more frequent in case of invasive
lobular carcinoma (21.4%) and presence of intraductal component (42.8%).
Conclusion: Sonography demonstrated a poor performance in the evaluation of
the status of surgical margins; however, due to its high NPV, both with 10-mm and
4-mm cut-off, it might be helpful in confirming complete excision of a US-detected
neoplasm and in ruling out the presence of invasive ductal carcinoma at surgical
margins.
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Additional ultrasound to mammography in case of breast density ACR
III/IV: Is there a higher detection rate of breast cancer in an analysis of
102,744 diagnostic processes?
F.K.W. Schaefer, A. Katalinic, P.J. Schäfer, B.M. Order, C. Wefelnberg, W. Jonat,
I. Schreer; Kiel/DE (fschaefer@email.uni-kiel.de)
(43/58) for MMG, 93% (54/58) for US, 97% (56/58) for MRI, and 97% (56/58) for
RVS, respectively. A virtual MPR image of the target tumor was displayed under
good condition correspondence with the US image in all patients. MRI-detected
suspicious lesions (BI-RADS 4) were found in 61 lesions which were not expected
from the previous conventional techniques. Of these, 48% (29/61) of suspicious
lesions (SL) could be identified only on repeated US, but 90% (55/61) of SL could
be identified easily using the RVS system (P 0.05). Histologically, 9.8% (6/61) of
SL were invasive carcinoma.
Conclusion: The present results suggest that RVS appears to be not time consuming technique which can identify a large part of incidental MRI findings, and can
accurately select the cases in which MRI-guide biopsy are required.
Scientific Sessions
B-498
11:33
Evaluation of mammographic diagnosis of breast cancer recurrence in
transversus abdominis muscle flap reconstructions
L. Johnston, M. Buckley, S. Refsum; Belfast/UK (lindabahari@yahoo.co.uk)
Purpose: Breast cancer recurrence in transversus abdominis muscle (TRAM)
flap reconstructions is low and diagnosis on mammogram alone is very low. The
study was undertaken to evaluate this premise based on the experience in our
institution.
Methods and Materials: All patients who had TRAM flap breast reconstruction
from January 1999 to March 2008 were identified from the Breast Service database.
Any recorded recurrences were validated using the Clinical Oncology Information
System (COIS).
Results: A total of 59 patients had TRAM flap reconstructions. One patient was
excluded from the study as she had an additional silicone implant. Only one
patient was found to have local recurrence and this was diagnosed clinically.
No patient was diagnosed with recurrence on mammogram alone. Five patients
were deceased and all were diagnosed with metastases not related to TRAM flap
recurrences. The remainder of the patients were undergoing annual clinical and
mammographic surveillance.
Conclusion: This study supported the premise that breast cancer recurrence in
TRAM flap reconstruction is low and that the mammographic detection rate of
nonpalpable recurrence alone is very low, being zero in our study. Therefore, the
usefulness of post TRAM flap reconstructions mammogram surveillance in the
evaluation of these patients requires further evaluation.
B-499
11:42
Computerized analysis of breast lesions using mammography and breast
ultrasonography
M. Lyra, C. Skouroliakou, S. Lyra, C. Georgosopoulos; Athens/GR
(mlyra@med.uoa.gr)
Purpose: The aim of this study is to extract texture descriptors of breast lesions
from mammographic and ultrasonic breast images, in order to evaluate the combined use of these two imaging modalities in the computerized classification of
breast lesions.
Methods and Materials: A total of 65 lesions (20 cysts, 30 benign solid masses and
15 malignant solid masses) were manually segmented from the mammograms and
the ultrasonic images. Four Haralick’s descriptors (homogeneity, contrast, energy
and correlation) were calculated as texture features of the segmented lesions.
Stepwise logistic regression and binary logistic regression were applied in order to
automatically classify breast lesions for different data combinations: a. taking into
account only the ultrasonic images, b. considering only the mammograms and c.
using data from both modalities.
Results: Classification success rate was higher (95%) when texture descriptors
extracted from both imaging modalities were used to construct the classification
model. A success rate of 89% was achieved when the ultrasonic images were used,
while the classification model based on the mammographic images reached an
80% of successfully classified lesions.
Conclusion: Computerized analysis of ultrasonic and mammographic images has
the potential to contribute to the diagnostic accuracy of distinguishing between benign
and malignant lesions of the breast, through the implementation of CAD systems.
B-500
11:51
Breast imaging in patients after bilateral breast augmentation with new
injectable filler materials
A. Artmann, N.A. Böhm, M. Geishauser, E. Rummeny; Munich/DE
(almut.artmann@lrz.tum.de)
Purpose: Breast augmentation with hyaluronic acid gel (HAG), a new filler material, is becoming a more frequently performed cosmetic surgery method. So far, no
data exist regarding the diagnostic accuracy of different breast imaging methods in
women after HAG augmentation. The aim of this study was to report first experiences
with multi-modality diagnostic breast imaging in symptomatic patients with HAG.
Methods and Materials: Five women (age range, 35-48 years) underwent HAG
injection. The patients were referred to our breast imaging service, 3 months to 2
years post treatment, because of pain, unknown nodularity and newly palpated
lumps. Mammography, ultrasound and 3D-(Gd)-enhanced (1.5 T) T1-w FLASH MR
mammography with a dedicated breast coil were performed.
Results: One patient was diagnosed with multicentric breast cancer (BC), two had
fibroadenomas and two had gel migration. In mammography, the radiographically
dense HAG impaired the depiction of BC and fibroadenomas. Ultrasound failed
to identify all breast cancers, but detected two fibroadenomas. However, because
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of the irregularly distributed HAG, assessing lesion features with ultrasound was
difficult, especially for the differentiation between benign and malignant masses.
MRI detected and correctly classified BC and fibroadenomas. Fast spin echo T2weighted images were the best for gel localization and displacement. In combination
with dynamic contrast-enhanced T1-w images and subtraction images, suspicious
enhancing masses were differentiated from HLA pockets.
Conclusion: Breast MRI seems to be the most effective imaging tool after breast
augmentation with HAG, because it allows to differentiate accurately between gel
pockets and breast masses and helps to detect gel migration.
10:30 - 12:00
Room G/H
Abdominal Viscera (Solid Organs)
SS 1001b
Liver and biliary system: MRI
Moderators:
B.J. Op de Beeck; Antwerp/BE
C.S. Reiner; Zurich/CH
B-501
10:30
Evaluation of liver iron concentration (LIC) in patients with thalassemia
and sickle cell disease at 3 T in comparison to 1.5 T
F.P. Junqueira1, G.M. Cunha1, A. Coutinho1, T.M. Doring1, A.A. Carneiro2,
J.L. Fernandes3, R.C. Domingues1; 1Rio de Janeiro/BR, 2Ribeirão Preto/BR,
3
Campinas/BR (mouracunha@hotmail.com)
Purpose: To determine the liver iron concentration (LIC) using relaxometry (T2*)
at 3 T and to compare to 1.5 T.
Methods and Materials: The measurement of the relaxation time T2* (known as
relaxometry) from MRI images can be used for evaluation of the iron concentration in the liver. MRI images of 12 patients were obtained at two different MR field
strengths, 1.5 T and 3 T, using a GRE sequence applying 15 different echoes. T2*
measurements were performed at both field strengths and compared by combining the data through linear regression. The LIC at 1.5 T was calculated using the
calibration equation established by a phantom at 1.5 T and a correction factor (the
slope of the previously linear combined T2*) was applied to the T2* values at 3 T
to measure the LIC at 3 T. The results were tested for linear relationship.
Results: The combined T2* data of all subjects at 1.5 and 3 T showed high linear
relationship (R = 0.98, P 0.001). The curve of the linear fit had a slope of 1.41 p 0.08.
The calculated LIC covered a range from 1.5 to 21 mg/g and the slope of the combined
data at different field strengths was 0.88 p 0.11 (R = 0.98, P 0.001).
Conclusion: The calculated LIC at 3 T shows a high linear relationship to the
1.5 T measurement. A correction factor has to be applied at 3 T when compared
to a calibrated 1.5 T scanner.
Keywords: MRI, T2*, liver iron concentration (LIC), thalassemia
B-502
10:39
Magnetic resonance imaging and magnetic resonance angiography of
the liver and hepatic vasculature in patients with hereditary hemorrhagic
telangiectasia (Rendu-Osler-Weber-disease)
A. Massmann1, P. Fries1, M. Wirth1, U.W. Geisthoff2, A. Buecker1, G.K. Schneider1;
1
Homburg a.d. Saar/DE, 2Cologne/DE
Purpose: To evaluate liver involvement in patients with hereditary hemorrhagic
telangiectasia (HHT).
Methods and Materials: 230 patients (mean age: 46.9; male 9; female 134) with
HHT, or first-degree relatives, underwent non-contrast and contrast-enhanced
(Gd-BOPTA 0.05 mmol/kg bodyweight) MRI of the liver for detection of hepatic
manifestations of HHT.
Results: MRI revealed 38/230 patients (mean age: 57; male 8; female 30) with
hepatic and vascular pathologies related to HHT. Hepatomegalia and hepatic
arterio-venous malformations (HAVM) were found in 28/38 and 21/38 patients,
respectively. Right-heart-insufficiency (RHI), due to HAVM, was present in 9 patients, who did not suffer from hemodynamically relevant pulmonary AVM (PAVM).
An enlarged diameter of the hepatic artery (HA) correlated with increased nodular
hyperplastic changes of the liver (19 patients), a lower RHI-rate, and inversely with
the diameter of the portal vein.
Conclusion: HHT-patients with a hepatomegaly and nodular hyperplastic changes
of the liver most likely have shunts at the sinusoidal level. Direct arterio-venous and
arterio-portal shunts are associated with an almost normal liver size without hyperplastic changes. The increased arterial blood supply to the liver could explain the
Scientific Sessions
nodular hyperplastic changes similar to the mechanism of focal overgrowth of liver
tissue discussed in the development of FNH. HAVM causing hyperplastic nodules do
not result in direct hemodynamical left-to-right-shunts, while HAVM without hyperplastic nodules is likely to cause RHI, even in the absence of PAVM. Consequently,
RHI might not be treated sufficiently by embolization of PAVM alone.
B-503
10:48
Accurate differentiation between small or atypical hemangiomas and
cystic or hypervascular metastases using ferucarbutran-enhanced MRI
A. Ba-Ssalamah, S. Machat, N. Bastati, S. Baroud, C. Kulinna, C.J. Herold,
W. Schima; Vienna/AT (ahmed.ba-ssalamah@meduniwien.ac.at)
B-504
10:57
Diffusion-weighted MRI for assessment of hepatic metastases:
Comparison with superparamagnetic iron oxide (SPIO)-enhanced imaging
H. Kim, J. Yu, D. Kim; Seoul/KR (hanab00@hanmail.net)
Purpose: The aim of this study was to validate diffusion-weighted imaging (DWI)
as a substitute for superparamagnetic iron oxide (SPIO)-enhanced MRI for assessment of hepatic metastases.
Methods and Materials: A total of 86 hepatic metastases in 22 patients were subjected to a retrospective analysis for detection rate on the DWI and SPIO-enhanced
MRI. DWI using spin-echo planar sequence (b factors of 50, 400 and 800 sec/mm2)
was performed before and after SPIO injection, and SPIO-enhanced T2*-weighted
images (SPIO-T2*) were compared with pre- and post-SPIO DWI (SPIO-DWI) by
two independent radiologists. Individual lesions were subjectively scored for the
conspicuity of the lesion using a five-grade scale (0-4). All lesions were divided into
two groups (group 1, 1 cm; group 2, r1 cm in the longest dimension).
Results: Regardless of the size of the lesions, all the conspicuity scores of DWI
were lower than that of SPIO-T2* (P 0.05), except for SPIO-DWI with b factor
of 50 sec/mm2 (P = 0.732). For lesions smaller than 1 cm, DWI with b factor of 50
sec/mm2, and SPIO-DWI with b factor of 50 sec/mm2 and 400 sec/mm2 showed no
significant difference in lesion conspicuity to SPIO-T2* (P = 0.06, 0.68, 0.35). Even
in DWIs, SPIO-DWI showed significantly higher conspicuity scores than precontrast
DWI regardless of the size of b factors in all lesions (P 0.05).
Conclusion: Despite the comparable value for the subcentimeter hepatic metastases between the DWI using small b factors and SPIO-T2*, precontrast DWI
cannot substitute for SPIO-enhanced imaging for assessment of overall hepatic
metastases.
11:06
Colorectal liver metastases: Detection with SPIO-enhanced MR imaging in
comparison with gadobenate dimeglumine-enhanced MR imaging and CT
imaging
K. Hekimoglu1, Y. Ustundag2, H. Engin2, O. Erdem2; 1Ankara/TR, 2Zonguldak/TR
(korayhekim@yahoo.com.tr)
Purpose: The aim of this prospective study was to compare the diagnostic role of
superparamagnetic iron oxide (SPIO)-enhanced liver magnetic resonance imaging
(MRI) versus gadobenate dimeglumine (Gd)-enhanced MRI and computed tomography (CT) investigations for the detection of liver metastases of colorectal cancer.
Methods and Materials: A total of 30 patients with liver metastases enrolled in
this study and 78 colorectal metastatic liver lesions were evaluated with dynamic
CT imaging, Gd-enhanced MRI and SPIO-enhanced MRI. Agreement between
the readers and three algorithms were analysed by Kappa statistics. Differences
between the lesion detection ratios of the methods were analysed by two proportion
z test. Sensitivity values were also calculated.
Results: Interobserver agreement between two reviewers (R1, R2) with kappa
analysis was found to be the best for the three modalities. Kappa values were
0.866, 0.843 and 1.0, respectively. For all the 78 liver colorectal metastases, SPIOenhanced MRI detected all lesions with two reviewers (100% sensitivity). This
sensitivity value was higher than Gd-enhanced MRI, and there was a significant
difference (P 0.05). Gd-enhanced MRI depicted 71 lesions and this modality
could not detect 7 lesions with two reviewers (91% sensitivity). This modality had
moderate sensitivity, and this value was greater than in CT imaging, so there was
a significant difference also (P 0.05). Dynamic triphasic CT imaging detected
64 (R1) and 65 (R2) lesions. This modality had the lowest sensitivity (R1:0.82,
R2:0.83 respectively).
Conclusion: Colorectal liver metastases were best detected with SPIO-enhanced
MR imaging against Gd-enhanced MR imaging and CT imaging. For diagnosing suspected colorectal liver metastases, this could be the primary alternative modality.
B-506
11:15
The 3.0 T MRI of the liver with a volumetric interpolated breath-hold
technique in comparison to MDCT: Preliminary results
W.K. Matzek, N. Bastati-Huber, S. Baroud, C. Kulinna, C.J. Herold, W. Schima,
A. Ba-Ssalamah; Vienna/AT (Wolfgang.Matzek@meduniwien.ac.at)
Purpose: To compare gadolinium-enhanced T1w 3D, GRE breath-hold sequence
(volumetric interpolated breath-hold examination or VIBE) for 3.0 T MRI with
contrast-enhanced MDCT in the detection and characterization of focal liver lesions (FLL) by using consensus evaluation and other findings as the reference
standard.
Methods and Materials: A total of 43 patients (22 men, 21 women; mean age
58 y) with 114 FLLs were examined in either 16- or 64-row MDCT (Sensation,
Siemens) and 3.0 T MRI (Trio, Siemens). Two observers reviewed the dynamic
contrast-enhanced MDCT and dynamic gadolinium-enhanced VIBE for FLL detection and characterization. The reference standard for diagnosis was obtained
from consensus review by the observers of both modalities, pathologic data and
follow-up imaging. The results of the contrast-enhanced MDCT and gadoliniumenhanced VIBE were compared.
Results: From a total of 114 FLLs (78 malignant, 34 benign), only 100 lesions
were detected by MRI (88%) at a consensus review. Only 92 lesions were detected
by MDCT (81%), and the difference between both modalities was not statistically
significant. Gadolinium-enhanced VIBE achieved an accuracy of 90 versus 78%
for MDCT in FLL characterization.
Conclusion: Gadolinium-enhanced T1wVIBE at 3.0 T is equal to MDCT in FLL
detection, however superior in characterization of focal liver lesions.
B-507
11:24
Accuracy of retrospective multimodality image fusion between 18 F-FDGPET and MRI in patients with malignancies of the upper abdomen
O.F. Donati, C.S. Reiner, T.F. Hany, B. Marincek, D. Weishaupt; Zurich/CH
(odonati@gmx.net)
Purpose: To evaluate the accuracy of retrospective rigid image fusion between
18 F-FDG PET and MRI of the upper abdomen.
Methods and Materials: Image fusion of PET and MRI was performed in 30 patients
with suspected malignancy of the liver or pancreas. Using a commercially available
image fusion tool capable of rigid manual point-based registration, PET-Images
were retrospectively fused by matching eight homologous points in MRI studies
and in the CT-part of PET/CT. Two separate readers (R1, R2) assessed accuracy
of image registration by determining the distances in the x-, y- and z-direction as
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Sunday
Purpose: To evaluate the efficacy of ferucarbotran-enhanced MRI in the differentiation of cystic or hypervascular metastases from small or atypical hemangiomas of
the liver using either the histopathologic results or long-term follow-up as standard
of reference.
Methods and Materials: A total of 112 focal hepatic lesions in 32 patients (20 m,
12 f, mean age 67.8 years) with clinical history of malignant disease and previous equivocal CT or US examinations were evaluated using unenhanced and
ferucarbotran-enhanced MRI. The SI pattern of each kind of lesion was assessed
and categorized into 3 categories: high SI on unenhanced T2-w TSE FS images with
significant SI loss on ferucarbutran-enhanced T2-w TSE FS images and increase of
SI on ferucarbutran-enhanced delayed 3D T1-w GRE images (category A), high SI
or moderate to low SI on unenhanced T2-w TSE FS images, respectively, without
SI change on both ferucarbutran-enhanced T2-w TSE FS and delayed-3D T1-w
GRE images (categories B and C).
Results: Lesions were categorized as follows according to the final diagnosis: 48
hemangiomas (category A), 12 cysts (category B), and 52 metastases (category
C). The only lesions showing a significant increase in SI on postcontrast T1-w 3DGRE images were hemangiomas on average by 60% (p 0.001). The only lesions
showing a significant decrease in SI on postcontrast T2-w TSE FS images were
hemangiomas on average by 40% (p 0.001).
Conclusion: The combined signal intensity pattern on ferucarbutran-enhanced
T2-w and T1-w helps to accurately differentiate small or atypical hemangiomas
from cystic or hypervascular metastases.
B-505
Scientific Sessions
well as the 3-dimensional distance between 4 and 6 anatomical landmarks. Quality
of fusion was graded using a three-point grading scale (1, poorly fused; 2, satisfactory fused; 3, correctly fused).
Results: Mean time of registration per patient was 2.04 min. Objective registration
assessment showed errors between 3.18-6.31 mm in x-axis [mean 4.16 mm (R1);
4.26 mm (R2)], 3.6-9.27 mm in y-axis (mean 6.18 mm; 5.8 mm) and 3.69-11.51 mm
in z-axis (mean 5.16 mm; 5.59 mm). The error in 3-dimensional distances between
points was 7.25-16.76 mm (mean 9.68 mm; 10.54 mm). In visual assessment, most
fusions were graded to be satisfactory or correctly fused [R1, R2: grade 3, 11/30
(36.7%), 22/30 (73.3%); grade2, 13/30 (43.3%), 8/30 (26.7%); grade1, 6/30 (20%),
0/30 (0%)]. Fusions were mostly comparable to hybrid PET/CT fusions. All of the
registrations were defined as “diagnostic” by both readers.
Conclusion: Retrospective rigid image fusion of PET and MRI of the upper
abdomen is feasible without adaptation in image acquisition protocols and shows
sub-centimeter registration errors.
B-508
11:33
Accuracy of preoperative T- and N-staging of gallbladder carcinoma using
gadolinium-enhanced dynamic MRI
S. Kim, J. Lee, J. Lee, S. Kim, J. Han, B. Choi; Seoul/KR (yali75@radiol.snu.ac.kr)
Purpose: To evaluate the performance of dynamic gadolinium-enhanced (Gd-E)
MRI in the T- & N- staging of gallbladder cancer (GBC).
Methods and Materials: 60 patients with surgically resected and pathologically
confirmed as GBCs were enrolled in this study. All patients were examined preoperative, Gd-E dynamic MRI. The T2 HASTE, T1 weighted in-/opposed phase and Gd-E
dynamic MRI were independently evaluated by two observers. They graded their
diagnostic confidence for: 1) loss of low SI on T2WI for differentiating rT1b from
bT1a lesions 2) disruption of outer ring of the GB wall on T1WI for diagnosing rT3
lesions, and 3) delayed subserosal enhancement for rT2 lesions using a 5-point
scale and evaluated final T-&N-stage of the GBCs. ROC analysis was performed
for evaluating diagnostic value of each findings. Interobserver agreement was
evaluated with kappa statistics. The sensitivity, specificity and overall accuracy of
T- & N- staging were evaluated.
Results: Az values for diagnosing 1) rT1b GBC on T2WI were 0.904 and 0.910, 2)
rT3 GBC on T1WI were 0.907 and 0.819, and 3) rT2 GBC on delayed phase were
0.915 and 0.862, respectively. The interobserver agreement was good (k=0.793).
The overall accuracy of T-&N-staging were 80 and 76.7% in observer 1, and 66.7
and 73.3% in observer 2, respectively. Az value of diagnostic ability to differentiate
rT1b from bT1a lesions were 0.874 and 0.840 in each observer (p = 0.0001).
Conclusion: The diagnostic ability to differentiate rT1b from bT1a lesions using Gd-E dynamic MRI was acceptable and this result can help for preoperative
surgical planning.
B-509
11:42
Diagnostic value of magnetic resonance cholangiography in the
identification of biliary tract strictures after liver transplantation
S. Kinner, A. Dechene, S.C. Ladd, P. Hunold, G. Gerken, T. Zoepf, J. Barkhausen,
T.C. Lauenstein; Essen/DE
Purpose: Post liver transplantation biliary obstruction is frequently caused by
strictures of the anastomoses or the intra- and extrahepatic bile ducts. Our study
aimed to assess the diagnostic accuracy of magnetic resonance cholangiography
(MRC) for the detection and characterization of post liver transplant biliary strictures
(PTBS) using endoscopic retrograde cholangiography (ERC) as the standard of
reference.
Methods and Materials: A total of 59 liver transplant patients (median age 49
years; 28 female, 31 male) with biliary obstruction were included in this blinded
prospective study. MRC was performed on 1.5 T scanner using 2D single shot
RARE as well as high-resolution navigator-corrected 3D MRC sequences in all
patients within 48 h prior to ERC. MRC and ERC were interpreted independently
by two trained radiologists and two gastroenterologists, respectively. The presence
of strictures and their localisation were assessed.
Results: ERC showed relevant PTBS in 47/59 patients, while MRC identified
stenoses in 48/59; 23/47 patients presented anastomotic strictures (AST), 18/47
patients ischemic type biliary lesions (ITBL) and 6/47 patients a combination of
both kinds of lesions in endoscopic retrograde cholangiography. As compared to
16/18 cases of ITBL, 19/23 cases of AST were identified correctly by MRC. MRC
overestimated/ misjudged stenosis more often in ITBL than in AST.
Conclusion: MRC is able to detect biliary stenoses in general with a slight tendency
to overestimation. However, in the presence of central stenoses, MRC is able to
assess the peripheral ducts even more precisely than ERCP.
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B-510
11:51
MRI of biliary tract complications in liver transplant recipients: “Cast” in
ischemia-type biliary lesions is bright in T1w
P. Hunold1, S. Kinner2, A. Dechêne2, T. Zoepf2, T.C. Lauenstein2, S.C. Ladd2,
J. Barkhausen1; 1Lübeck/DE, 2Essen/DE (peter.hunold@uk-sh.de)
Purpose: Biliary tract complications after liver transplantation (LTx) including ischemic type biliary lesions (ITBL) are common. However, ITBL remain a diagnostic
challenge. “Cast” - bile tract obstructing epithelial cell debris - being one correlate
of ITBL is difficult to detect with non-invasive imaging techniques. Aim of this study
was to evaluate the accuracy of MRI for the detection of intrabiliary cast compared
to endoscopic retrograde c holangiography (ERC).
Methods and Materials: Fifty-nine patients (34 males; 49 p 14 years) suspicious
of ITBL underwent ERC 640 p 991 days after cadaveric or living-donor LTx. Within
48 h prior to ERC, 1.5 T liver MRI was performed using the following protocol:
T1w 2D FLASH, T2w HASTE, T2w TSE, 2D-RARE MRCP, navigator-gated 3D
high-resolution MRCP, dynamic Gd-enhanced T1w 3D VIBE fs, T1w 2D FLASH fs
post Gd. The different MRI sequences were compared to ERC in detecting ITBL
and cast.
Results: ERC confirmed ITBL in 28 cases, cast was found in 11 of those. ITBL was
consistently confirmed and excluded by both, ERC and MRCP in 24 and 19 pts.,
respectively. In 14 pts., MRCP diagnosed ITBL while ERC did not. ERC detected
cast in 14 pts., MRCP only in 5 of them, additionally yielding 4 false positives.
However, pre-contrast T1w images detected cast as hyperintense structures in
11/14 pts with cast at ERC.
Conclusion: Cast as a correlate of ITBL appears hyperintense on non-enhanced
T1w images. The combination of MRCP and T1w sequences yields higher diagnostic
value than MRCP alone making imaging of ITBL more reliable.
10:30 - 12:00
Room I
Physics in Radiology
SS 1013
New advances in CT
Moderators:
A. Noel; Vandoeuvre-les-Nancy/FR
K. Perisinakis; Iraklion/GR
B-511
10:30
CT image reconstruction with extended z-range
R.P. Grimmer1, M. Oelhafen2, U.V. Elstroem3, M. Kachelrieß1; 1Erlangen/DE,
2
Baden-Dättwil/CH, 3Aarhus/DK (rainer.grimmer@imp.uni-erlangen.de)
Purpose: Extend the reconstructable z-range in cone-beam CT.
Methods and Materials: For circular cone-beam CT the Feldkamp algorithm is
most commonly used. In most applications projection data from 360° or more are
available. Usually only those slices are reconstructed where each pixel is viewed
under the full 360° range. Yet cone-beam reconstruction is possible whenever a
voxel has been viewed by at least 180°. There are slices that receive contributes
from less than 360° but from more than 180°. These should be reconstructed in
order to make better use of the dose and to extend the z-range. We developed and
evaluated an algorithm that reconstructs also those slices: the extended Feldkamp
algorithm (xFDK). In comparison to other algorithms that solve the same problem,
xFDK does neither require multiple convolutions nor multiple backprojections and
is therefore much more efficient. To evaluate xFDK we used the geometry of the
Varian-OBI scanner (fan-angle=15°, cone-angle=11°, FOM=26 cm) but our findings also apply to other C-arm CT scanners. Simulated and clinical patient data
were processed.
Results: For our geometry, xFDK extends the z-range by 13% with nearly identical
image quality. Image quality was evaluated in terms of image noise, spatial resolution
and artifacts. xFDK was successfully applied to clinical patient data.
Conclusion: xFDK increases the reconstructable z-range in a computational efficient way. Dose usage with xFDK is increased by 10 to 20% (depending on the
scanner geometry) compared to standard Feldkamp approaches that are in use
in today’s flat-panel CT scanners.
Scientific Sessions
B-512
10:39
A new method to assess spatial resolution in CT
R. Grimmer, M. Kachelrieß; Erlangen/DE (marc.kachelriess@imp.uni-erlangen.de)
Purpose: To assess the point spread function (PSF) and the modulation transfer
function (MTF) of a CT scanner using a single measurement and standard reconstruction parameters.
Methods and Materials: To quantify the spatial resolution in CT, one typically
performs separate measurements for the lateral and the longitudinal PSF. Many
procedures further require reconstructions with very small voxel sizes, e.g. when
wire phantoms are scanned. This, however, may already change the shape of the
PSF. We propose to measure a sphere, perform a standard image reconstruction
and evaluate profiles through the sphere surface. The radial symmetry of CT scanners allows to reduce the dimensionality of the PSF from three to two by radial
averaging. It is shown in this paper that the resulting two-dimensional profiles can
be decomposed into a radial and a longitudinal component by two-dimensional
parallel-beam filtered backprojection. Our method was evaluated using simulations
and flat panel cone-beam CT measurements of a homogeneous sphere.
Results: The longitudinal and radial PSFs, and the corresponding MTFs, highly
agree with those obtained with conventional methods, for both the simulations and
the measurements. Figures of merit extracted from the curves, such as the full width
at half maximum of the PSF or the 10% value of the MTF, differ by less than 5%
between the new method and the conventional approaches.
Conclusion: Our technique, which requires only one standard measurement and
standard reconstruction of a sphere, accurately quantifies the spatial resolution of
a CT system. Therefore, it appears as a superior alternative to existing methods.
B-513
10:48
Improved cardiac CT angiography using a motion-compensation
reconstruction technique
U. van Stevendaal, J. von Berg, C. Lorenz, H. Schmitt, P. Forthmann, M. Grass;
Hamburg/DE (Udo.van.Stevendaal@philips.com)
B-514
10:57
A dedicated rawdata-based metal artifact reduction method for flatdetector CT
D. Prell, Y. Kyriakou, W.A. Kalender; Erlangen/DE
(Daniel.Prell@imp.uni-erlangen.de)
Purpose: Metal implants cause non-linear artifacts in the reconstructed image. We
evaluated the efficiency of a dedicated metal artefact reduction (MAR) approach
for flat-detector CT (FD-CT).
Methods and Materials: Our MAR approach uses 3D segmentation of the metal
in the initially reconstructed 3D volume. Sub-volumes are backprojected onto the
detector to identify the metal in the projection data and to replace it by 2D linear
interpolation before reconstruction. Subsequently, standard Feldkamp reconstruction is performed.
Performance was evaluated by phantom and patient measurements on a C-arm
FD-CT system (Artis Zeego, Siemens Healthcare, Germany). Data was acquired
B-515
11:06
CT metal artifact reduction with scout-view assisted metal localization
S. Prevrhal1, G. Du1, T. Funk2, B.M. Yeh1; 1San Francisco, CA/US, 2Newark, CA/US
(sven.prevrhal@radiology.ucsf.edu)
Purpose: Metal causes artifacts in CT images that can render them nondiagnostic.
Localization of metal is the first step in most metal artifact reduction schemes and
is often performed in natively reconstructed images at large computational cost.
The hypothesis of our work was that simple CT scanogram (scout) views provide
accurate localization of metal in the projection data without the need for preliminary
native image reconstruction, cutting reconstruction time in half.
Methods and Materials: Phantoms of one- and two-sided chrome-cobalt hip
replacements with adjacent lesions were imaged on a 16-slice CT scanner. Userassisted segmentation of the hip prostheses in the scout views was transferred to
the spiral data sets to identify metal sinusoidal trace regions. After automatic refinement of the metal traces they were replaced with per-projection linear interpolation
of non-metal projections and edge-smoothing and reconstructed with either filtered
backprojection (FBP) or iterative expectation-maximization reconstruction (EM).
Performance was quantified by signal-to-noise (SNR) and percent accuracy error
(PAE) by comparison to reference images with the prostheses removed in three
representative regions of interest (ROIs).
Results: Both EM and FBP metal artifact reduction reconstruction achieved satisfactory metal artifact suppression with average PAE errors of 4.5% and 5.5%,
respectively versus 7.1% for native images and SNR improved to 40.3 (EM) and
21.1 (FBP) versus 16.5 (native).
Conclusion: The new artifact suppression design adds minimal computational
overhead to non-metal artifact reduction reconstruction and improves images so
that previously obscured fine details are revealed.
B-516
11:15
Hyperfast cone-beam spiral CT image reconstruction
M. Kachelrieß, S. Steckmann, M. Knaup; Erlangen/DE
(marc.kachelriess@imp.uni-erlangen.de)
Purpose: To increase the reconstruction speed for exact and approximate conebeam spiral CT image reconstruction.
Methods and Materials: Cone-beam spiral CT image reconstruction is computationally highly demanding. Most computations are required for the backprojection.
Compared to reconstructions from circular scans there is a significant complication:
the illumination of each voxel, i.e. the range of angles the voxel is seen by the X-ray
cone, is a complex function of the voxel position. A voxel-specific weight w (x, y,
z, a) needs to be multiplied to each voxel (x, y, z) at each projection angle a. This
weight function has no analytically closed form and must be determined numerically.
Storage of the weights is prohibitive due to the large number of entries. We propose
an algorithm that utilizes the spiral symmetry and removes the z-dependence from
w which now reduces from a 4D to a 3D function. Image quality is evaluated using a
clinical cone-beam reconstruction algorithm combined with our new backprojection
approach to reconstruct patient data acquired with a clinical CT scanner.
Results: Our backprojection processes 81 images per second (5122 pixels) on
a standard PC. It is 11x faster than our optimized reference reconstruction that
does not make use of the spiral symmetry. Spatial resolution and image noise
are identical to the reference images. Visually, the patient images do not show
any differences.
Conclusion: Hyperfast spiral cone-beam CT image reconstruction is possible with
standard PCs using our approach. The speed-up can also help to bring iterative
image reconstruction with reduced patient dose levels to clinical routine.
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Purpose: Challenges for image reconstruction in cardiac CT arise from the rather
fast cardiac motion and inconsistent data that are associated with cardiac gating
combined with helical scanning. We present a motion-compensated reconstruction
(MCR) method that can suppress motion blurring and yield improved data utilization, which can either increase the signal-to-noise ratio (SNR) or lower the required
dose for retrospective gating.
Methods and Materials: As a first step, low-pitch helical data are reconstructed
at low resolution at numerous phase points through the cardiac cycle. As a second
step, an automatic cardiac adaptive surface model is applied to each reconstructed
phase and, from these surfaces, a motion-vector field is calculated for each voxel
in the region of interest. Finally, a motion-compensated reconstruction is carried
out using those projections, which cover the cardiac phases for which the motionvector field has been determined. The method has been successfully applied to
clinical data sets acquired with a Philips Brilliance 64 CT scanner.
Results: Motion artifacts are reduced clearly and coronary arteries can be depicted appropriately even in phases of relatively strong motion. Since larger gating
windows can be used for reconstruction without loss of sharpness, the images
show a better SNR than results obtained with reconstruction algorithms without
compensating the motion.
Conclusion: Motion-compensated reconstruction is feasible by employing 4D
heart model adaptation for the motion estimation. The method has the potential to
offer significant improvement in the imaging of the heart and to provide 4D object
motion information for functional analysis.
for tissue-equivalent phantoms (QRM GmbH, Möhrendorf, Germany) and different
human body regions. Accuracy of correction (spatial resolution, noise) was investigated in subtraction and noise images and by comparison of reference images
without metal inserts. Different regions of interest (ROIs) were evaluated for noise
assessment and CT value consistency.
Results: Metal artifacts were efficiently reduced both in phantom and patient images and a comparison of CT values of the corrected with the reference image
confirmed consistent CT values (deviations of up to 800 HU were reduced to below
40 HU). Noise reduction to the noise level measured in the corresponding reference image was achieved in a similar manner. No resolution losses were caused in
areas at a distance greater than 2 mm to the implant. Detectability of low-contrast
objects was improved.
Conclusion: MAR can improve the quality of FD-CT images containing metal
artifacts and allow medical diagnosis of areas close to the metallic prosthesis.
Scientific Sessions
B-517
11:24
Advanced statistical reconstruction algorithm for CT dose reduction
J. Hsieh, F. Dong, J. Fan, B. Li, M. Kulpins, J.-B. Thibault, X. Tang; Waukesha, WI/US
(jiang.hsieh@med.ge.com)
Purpose: CT dose reduction is an important issue. Although iterative reconstruction
(IR) offers substantially improved image quality at reduced dose, computational
complexity is beyond the reach for many applications. We present an advanced
statistical reconstruction (ASR) that offers significant dose reduction while providing
reconstruction speed suitable for daily clinical usage.
Methods and Materials: We first condition the projections to remove bias introduced in the logarithmic operation under photon starvation conditions. An initial
image based on the filtered backprojection (FBP) is generated and image update
operation is performed in two sequential steps: an iterative regularization and an
image update based on comparison between measured and synthesized projections. Simplified system matrix is used for speed. The update process stops after
a pre-determined criterion is met. ASR is significantly different from existing IR in
which both the difference and the regularization terms are used to produce the
cost function for updating.
Results: Phantom and patient studies were conducted. Phantom studies show that
ASR offers a 50% dose reduction while maintaining spatial resolution compared
to an FBP algorithm. Clinical studies demonstrate that ASR produces images of
similar quality at half the radiation dose as compared to FBP at full dose. ASR
was implemented on a hardware that generates images at significantly higher
than 10 images/s.
Conclusion: We present an ASR algorithm that offers significant dose reduction
while maintaining image quality. ASR provides better visualization of small anatomical structures as compared to FBP. Its computational advantage over conventional
IR algorithms is demonstrated.
B-518
11:33
A novel spatiotemporal filter for artifact and noise reduction in CT
R. Raupach, H. Bruder, B. Schmidt, E. Klotz, T.G. Flohr; Forchheim/DE
(rainer.raupach@siemens.com)
Purpose: To reduce the radiation dose of CT perfusion scans and dynamic CTAs
and to improve the CT number stability for cardiac perfusion exams.
Methods and Materials: We present a new spatiotemporal filter (STF) with various applications. After reconstructing a time series, images were decomposed into
multiple spatial frequency bands (FBs). A temporal convolution was performed
separately for each band with FB-dependent filter width. Final images were derived by recombining the FBs. Two different applications were examined: (1) For
CT perfusion or dynamic CTAs, narrow (broad) temporal filters were used at low
(high) frequencies in order to preserve the temporal resolution of the time density
information, but reduce pixel noise. (2) For cardiac perfusion, different cardiac
phases were reconstructed as a time series. As opposed to 1, temporal convolution
was broad (narrow) in the low (high) FBs in order to preserve details at maximum
temporal resolution.
Results: Method 1 allowed for noise reduction of typically 60%, or equivalently, increasing the contrast to noise ratio (CNR) by a factor of 2.5. The time density function
was significantly improved in terms of statistical fluctuations without deteriorating its
temporal resolution. Method 2 reduced CT number variations due to partial scans
by a factor of 3, yielding more accurate time density information.
Conclusion: The STF improves image quality for dynamic CTAs and CT perfusion, which can be utilized in terms of radiation dose reduction or increased spatial
resolution at the same CNR. In the second operation mode, more accurate cardiac
perfusion evaluation is enabled by the STF.
B-519
11:42
Evaluation of concepts for spiral CT imaging with high-pitch values in
DSCT
D. Ertel1, H.-J. Lee1, J.U. Krause1, T. Flohr2, W.A. Kalender1; 1Erlangen/DE,
2
Forchheim/DE (dirk.ertel@imp.uni-erlangen.de)
Purpose: For dual-source CT systems, scan time per volume can be decreased
and temporal resolution increased. Just the same, pitch values can be increased
compared to single-source CT systems. We evaluated the performance of spiral
CT with pitch values of up to 3.0.
Methods and Materials: Measurements were performed using a dual-source CT
(SOMATOM Definition, Siemens, Forchheim) with 0.33 s rotation time for pitch
values of 0.35, 0.5, 1.0, 2.0 and 3.0. We assessed the slice sensitivity profile (SSP)
and the temporal modulation transfer function (t-MTF) [Ertel et al. Radiology 2008;
248 (3) 1013-1017]. Additionally, scanning of the cardiac region was performed in
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pigs, which were scheduled for cardiac exams, with a pitch value of 3.0 for visual
assessment.
Results: Resolution in the z-direction remained essentially constant even for increased pitch values with a slight decrease for a pitch of 3.0; the 10% value of the
MTF curve of the SSP amounted to 12.30 (p = 0.35), 12.09 (p = 0.5), 12.39 (p =
1.0), 12.03 (p = 2.0) and 11.41 (p = 3.0) [lp/cm]. The in-plane t-MTF was not affected
by the pitch value meaning constant temporal resolution independent of pitch. CT
images of the in-vivo pig scans confirmed good image quality at p = 3.
Conclusion: CT imaging with a pitch value of up to 3.0 can provide unimpaired
image quality with respect to spatial and temporal resolution in DSCT. Scan time
can thereby be decreased significantly. Applications to cardiac imaging with lower
dose appear possible.
B-520
11:51
Ring artifact correction methods for flat-detector CT
D. Prell, Y. Kyriakou, W.A. Kalender; Erlangen/DE
(Daniel.Prell@imp.uni-erlangen.de)
Purpose: Imperfect calibration or defect detector elements may cause concentric
ring artifacts in CT images. We evaluated two ring artifact correction methods for
flat-detector CT (FD-CT) and their effectiveness in phantom studies and in clinical
examples.
Methods and Materials: We present a comparison of two post-processing ring
artifact correction methods for FD-CT, based on different thresholds and adaptive,
distance-depending median filterings of the reconstructed slices. While the first
method works in Cartesian coordinates, the second performs a transformation to
polar coordinates. Measurements were performed on a C-arm FD-CT system (Artis
Zeego, Siemens Healthcare, Germany). In a water phantom, standard deviations
and CT values were measured in central and peripheral regions of interest (ROIs).
The correction algorithms were applied to measurements with different acquisition
angles, i.e. partial scan (218°) and full scan (360°) and different detector pixel binning
(1 x 1, 2 x 2 and 4 x 4). Patient data sets were used for performance validation.
Results: Ring artifacts were efficiently reduced both in phantom and patient data.
Standard deviations corresponding to image noise were reduced by up to 20%.
Homogeneity (IEC 61223-3-5 standard) was increased by 25%. Correction worked
superior in 360° scans compared to 218° scans for both methods. The best image
quality was achieved using polar coordinates for correction, but needed additional
computational time.
Conclusion: Both correction methods improve the quality of FD-CT images
containing concentric ring artifacts with negligible impact on image resolution and
at acceptable computational costs. The correction via polar coordinates worked
superior to correction in Cartesian coordinates.
10:30 - 12:00
Room K
Pediatric
SS 1012
Fetal and neuro imaging
Moderators:
O. Flodmark; Stockholm/SE
R.R. van Rijn; Amsterdam/NL
B-521
10:30
Fetal cardiovascular MRI: Steady-state free precession sequences and
angio-MR sequences for the management of fetuses with congenital
cardiac malformations
S. Savelli, M. Di Maurizio, A. Tomei, F. Fierro, F. Ventriglia, L. Manganaro; Rome/IT
Purpose: To assess the feasibility of steady-state free precession sequences
(SSFP) sequences and angio-MR sequences to evaluate congenital heart disease
(CHD).
Methods and Materials: A total of 43 pregnant women with 43 fetuses with a
previous diagnosis of congenital heart disease were examined using fetal MRI
with SSFP static and dynamic images to evaluate the heart and vessels and with
T1 GE angio-MR sequences to assess the aorta. Both direct and indirect signs of
CHD were investigated and in all cases MRI findings were compared with postnatal
echocardiograms or autoptic findings considered as the standard of reference.
Results: A cardiac disease was diagnosed in 42/43 fetuses by postnatal echocardiograms (40) and autoptic findings (2) and disclosed in 1 fetus. In all cases,
MRI imaged the fetal heart identifying cardiac anomaly in 38 fetuses, missing
the diagnosis in 4 fetuses and disclosing the pathology in1 fetus. In two fetuses
Scientific Sessions
with ventricular septal defects, angio-MR excluded a possible association with
coartaction of the aorta; in one fetus with a hypoplastic left heart syndrome,
angio-MR detected an associated coartaction of the aorta. Direct signs permitted
the diagnosis in 24 fetuses, both direct and indirect signs in 7 fetuses and only
indirect signs in 9 fetuses.
Conclusion: Fetal cardiovascular MRI evaluation is a valuable tool to investigate
abnormal cardiac conditions and to corroborate US diagnosis and exclude possible
associated cardiac and extracardiac abnormalities.
B-522
10:39
Assessment and imaging features of lymphangiomas in fetal MR
C. Koelblinger, P.C. Brugger, S. Nemec, D. Bettelheim, C.J. Herold, D. Prayer;
Vienna/AT (claus.koelblinger@meduniwien.ac.at)
B-523
10:48
MRI with diffusion-weighted imaging and apparent diffusion coefficient
assessment in the evaluation of placental changes during gestation
F. Fierro, A. Tomei, M. Di Maurizio, F. Coratella, S. Savelli, L. Manganaro; Rome/IT
Purpose: To investigate the placental ageing evaluating the changes of signal
intensity and the measurement of placental tissue apparent diffusion coefficient
(ADC) value of normal placenta in relation to various gestational ages.
Methods and Materials: A total of 102 pregnant women (Age range 18-44,
mean 29 years) with 105 fetuses (gestational age range 19-40, mean 25 weeks)
underwent MRI for suspected disorders in several organs. A multiplanar study of
fetuses was obtained by using T2-weighted sequences and echo planar imaging
(EPI); notwithstanding the diagnostic question, in every study also the placenta
was included. Diffusion-weighted images and ADC maps were evaluated and
placental tissue ADC value was calculated for all fetuses divided into three groups
based on gestational age (I group: from 20 to 26 gestation week; II group: 27-33;
III group: 34-40). Patients with suspected utero-placental insufficiency or placental
anomalies were excluded.
Results: In the quantitative evaluation of normal placenta, MRI showed an inverse
correlation between ADC values on ADC maps and gestational age (GA). ADC
values had a range from 800 to 2,500 µm2/s and showed a decrease in the first
group, a stationary phase in the second group and a new decrease in the third one.
Moreover, a qualitative evaluation of diffusion-weighted images demonstrated that
the signal intensity of the normal placenta appeared more hypointense in relation
with the placental ageing.
Conclusion: Diffusion-weighted imaging (DWI) with ADC mapping can be useful
for the evaluation of normal placenta and may become a tool of assessing normal
placental development by measurement of placental tissue ADC values.
10:57
Fetal functional MRI on 1.5 T and 3 T: Changes of R2* in the fetal brain and
lung during hypoxia
M. Frisch, J. Yamamura, H. Kooijman, K. Hecher, G. Adam, U. Wedegaertner;
Hamburg/DE (frisch1@gmx.net)
Purpose: To compare delta R2* in the brain and the lung of fetal sheep during
hypoxia obtained with different field strength (1.5T versus 3.0T).
Methods and Materials: Measurements of the fetal sheep brain and lung were
performed on 17 pregnant ewes at a 1.5T (n = 8) and a 3.0T (n = 9). On both
scanners, a T2*-weighted single-shot gradient-echo EPI-sequence (3.0T: TE =
30 msec, 1.5T: TE = 50 msec) was used to measure T2*-weighted images ($R2*)
in the brain and lung of the fetal sheep during control and hypoxia. Fetuses were
chronically instrumented with a carotid catheter to measure the fetal arterial oxygen saturation (FetSO2). $R2* was correlated with FetSO2, and linear regression
analysis was performed.
Results: A total of 32 examinations on 17 ewes were performed (1.5T: n = 7
brains, n = 7 lungs; 3.0T: n = 9 brains, n = 9 lungs). At 1.5T, FetSO2 was reduced
from 84% during control to 10% during hypoxia. The $R2* was -3.9 1/s in the
brain and -5.4 1/s in the lung. At 3.0T, the FetSO2 was reduced from 71.2% during
control to 8.7% during hypoxia. The $R2* was in the brain -5.8 1/s in the brain and
-6.9 1/s in the lung. $R2* in brain (1.5T: r = 0.93, p = 0.0005; 3.0T: r = 0.82, p =
0.0007) and lung (1.5T: r = 0.61, p = 0.04; 3.0T: r = 0.86, p = 0.0003) correlated
significantly with FetSO2.
Conclusion: At both field strengths an alteration of the BOLD signal intensity
during hypoxia was identified in fetal brain and lung. Changes in $R2* in the brain
and lungs are proportional to the field strength.
B-525
11:06
Human ear development demonstrated by in-vivo fetal MR
N. Hachemian, P. Brugger, M. Weber, D. Prayer; Vienna/AT
(nilouparak.hachemian@meduniwien.ac.at)
Purpose: The aim of this study was to illustrate the development of the fetal ear
with MR metric data.
Methods and Materials: A total of 208 unsedated fetuses from singleton pregnancies with assumed normal auditory development were examined on a 1.5 T unit
using T2-weighted 2-4 mm thick coronal sections through the temporal bone. Five
age groups were defined: A: 16-20 gestational week (GW), B: 21-25 GW, C: 26-30
GW, D: 31-35 GW and E: from 36 GW until the date of birth. Measured parameters included the length of the auricle (LA), the widest diameter of the cochlea
(WDC), the semicircular canals and ducts (WDSCD) and the largest width of one
semicircular duct (LWSD).
Results: The mean LA differed significantly between group A (11.25 mm) and C
(17.27 mm), A and D (19.07 mm), A and E (22.47 mm), and B (14.85 mm) and
E (22.47). The WDC (A: 4.82 mm, B: 4.77 mm, C: 5.05 mm, D: 5.08 mm and E:
4.85 mm) did not differ significantly between the groups. The WDSCD showed significant differences between A (10.83 mm) and C (13.60 mm), A and D (14.99 mm)
as well as between A and E (15.99 mm). Furthermore, the comparison between B
(12.24 mm) and D (14.99 mm), B with E (15.99 mm) and that of C (13.60 mm) with
E (15.99 mm) showed siginificant differences. The LWSD showed no significant
difference in the post-hoc test by Hochberg between A (2.44 mm), B (2.68 mm),
C (3.07 mm), D (3.63 mm) and E (3.08 mm).
Conclusion: The presented normal values will be helpful in the evaluation of
fetal ear pathology. However, larger sampling sizes will be necessary to define
percentile curves.
B-526
11:15
MR imaging of intra- and extracranial haemorrhage in the neonate: Birth
injury or non-accidental injury?
L.I. Wallis, S.V. Gandhi, M.F. Smith, M.N.J. Paley, P.D. Griffiths, E.H. Whitby;
Sheffield/UK (l.wallis@sheffield.ac.uk)
Purpose: Subdural haematomas in infants are associated with non-accidental
head injury. We sought to establish the frequency and natural history of subdural
haemorrhages in asymptomatic term neonates and whether the presence of intracranial bleeds is reflected in an increased number of extracranial bleeds and if
the delivery method influenced this.
Methods and Materials: Term babies were imaged within 48 hours of delivery
using a 0.2 T MRI scanner. Obstetric details were recorded retrospectively from
the patient’s notes. A neonatal radiologist recorded the incidence of subdural or
subgaleal haemorrhage and cephalohematoma. Statistical analysis used normal
vaginal delivery (NVD) as the baseline.
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Purpose: To evaluate the imaging findings of lymphangiomas diagnosed with
fetal MRI.
Methods and Materials: MR scans of six fetuses with postnatally proven lymphangiomas were evaluated. MR imaging was performed between the 18th and 35th
gestational week at 1.5 T using a cardiac phased-array coil. MR evaluation included:
number, size and signal intensities (T1w ,T2w, EPI) of the cysts, thickness of the
septae, margins, presence of blood breakdown products, change in size or signal
intensity (three patients with multiple examinations), exact expansion of the lesions
to the adjacent anatomical structures and concomitant pathological findings. Results
were compared with postpartum clinical assessment and MR or ultrasound in five
patients. Histologic specimens were available in three patients.
Results: One retroperitoneal, two thoracic and three cervical lymphangiomas
(diameters between 3.3 and 12 cm) were found in our series. All lesions consisted
of macrocysts and additional solid appearing parts were found in three lymphangiomas. Blood breakdown products were found in one lesion. Two patients
showed concomitant pathologies. Concerning tumor expansion, agreement with
postpartal imaging and/or surgery was excellent. In cases with cervical lesions, the
trachea was not distorted, making an EXIT procedure unnecessary. One pregnancy
was terminated on the basis of imaging findings.
Conclusion: Fetal lymphangiomas display the same MR features as postnatal
ones. Intrauterine MR characterization of such lesions include exact delineation,
detection of associated and/or concomitant pathologies and differential diagnosis
against other cystic pathologies. Patient management may be altered with respect
to the type and/or time of treatment, and to the continuation or termination of
pregnancy.
B-524
Scientific Sessions
Results: Imaging of 494 neonates: NVD (n = 269), forceps (n = 35), ventouse (n =
65), failed ventouse and subsequent forceps (n = 29), elective caesarean section
(n = 49) and emergency caesarean section (n = 47) revealed 38 subdural haemorrhages (7.7%). Of these, 19 were NVD, 3 forceps deliveries (odds ratio = 1.23), 6
were forceps after attempted ventouse delivery (OR = 3.4; P = 0.02), 8 followed
ventouse delivery (OR = 1.96) and one followed emergency caesarean section
(OR = 0.38). All had resolved by the 4 week rescan with no reoccurrence to date.
The distribution of subgaleal haemorrhage (n = 18) and cephalohaematoma (n =
11) followed that of subdural haemorrhage.
Conclusion: High numbers of clinically silent intracranial and extracranial haemorrhages occur most frequently in instrumental deliveries and resolve spontaneously without detrimental effects within 4 weeks. Subdural haemorrhages after 4
weeks of age are therefore not related to birth injury and traumatic causes must
be considered.
B-527
11:24
Periventricular leukomalacia in preterm children: Gray and white matter
and cerebrospinal fluid changes assessed with MRI
L.C. Tzarouchi, L.G. Astrakas, A.K. Zikou, V. Xydis, P. Kosta, S. Andronikou,
M.I. Argyropoulou; Ioannina/GR (ltzar@cc.uoi.gr)
Purpose: To assess total volume of GM, white matter (WM) and cerebrospinal fluid
(CSF) and individual volume of 116 GM areas in patients with PVL.
Methods and Materials: Using a T1-weighted three-dimensional spoiled gradientecho sequence, total GM, WM and CSF volume was evaluated in 10 preterm born
subjects (gestational age 31.7p4.2 weeks and corrected age 27.8p21.7 months)
with MRI findings of PVL and in 46 age-matched preterm controls. Volumes of 116
GM areas were calculated after their segmentation using the Statistical Parametric
Mapping (SPM5) and the Individual Brain Atlas Statistical Parametric Mapping
(IBASPM) software packages.
Results: Total CSF volume was higher (300.8p56.2 cm3) and WM volume was
lower in PVL patients (182.1p40.5 cm3) than in normal subjects (219.0p61.8 cm3,
222.9p67.2 cm3, respectively), p 0.05. No significant difference was found in
total GM volume. Significant volume differences were found between patients and
controls in specific GM areas: Frontal Superior Orbital 3.6p0.6 cm3, 3.1p0.7 cm3,
p=0.03, Posterior Cingulum 2.0p0.5 cm3, 1.5p0.2 cm3, p 0.001, Lingual 9.7p1.7 cm3,
8.2p1.3 cm3, p=0.003, Putamen 2.5p0.6 cm3, 1.7p1.4 cm3, p 0.001, Thalamus
2.6p0.9 cm3, 1.8p0.4 cm3, p 0.001, respectively.
Conclusion: Patients with PVL present increased CSF and decreased WM volume.
GM segmentation reveals increased volume of the putamen, thalamus and of individual GM areas related with the WM the most affected from PVL. Development
of extensive cortical connections and/or persistence of transient fetal connections
may be proposed as a mechanism of brain reorganization.
B-528
11:33
Age related gray matter changes in preterm subjects: A MRI study
L.C. Tzarouchi, L.G. Astrakas, A.K. Zikou, M. Papastefanaki, V. Xydis,
S. Andronikou, M.I. Argyropoulou; Ioannina/GR (ltzar@cc.uoi.gr)
Purpose: To assess individual volume of 116 GM areas in normal preterm born
children.
Methods and Materials: Sixty seven preterm born children (corrected age:
12.7p9.9 months, gestational age: 32.9 p2.3 weeks) with normal structural MRI
were included in the study. Using a T1-weighted high resolution three-dimensional
spoiled gradient echo sequence, volumes of 116 GM areas were calculated after
their segmentation using the Statistical Parametric Mapping (SPM5) and the Individual Brain Atlas Statistical Parametric Mapping (IBASPM) software packages. Non
linear regression analysis assessed age dependency of volume data for every GM
area. The model used was the monoexponential function y=A-B*exp (-x/C) where
y: volume at corrected age x, A: volume at the end of maturation, B: total change
and C: rate of change. The 99% of the final volume (A99%) was reached at time
t (99%) =-C*ln (0.01*A/B).
Results: All supratentorial GM areas followed the monoexponetial function model
reasonably but the pallidum and cerebellar structures had a poor goodness of fit.
Volume increase of the individual GM areas followed a caudal to cephalad and a
dorsal to ventral pattern. Thalamus, putamen and caudate nucleus reached A99%
earlier than most cortical GM areas. Visual cortex, postcentral and precentral cortices reached A99% earlier than parietal, frontal and temporal cortices.
Conclusion: GM volume changes follow age related maturational changes of the
regional white matter. Maturation of white matter tracts connecting cortical and
subcortical GM may be at the base of GM volume increase.
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B-529
11:42
Hypoxia, intradural hemorrhage and subdural bleeding in the pediatric and
perinatal post-mortem - are they related? A study combining the use of
autopsy and post mortem magnetic resonance
E.H. Whitby, A. Sprigg, M. Cohen; Sheffield/UK (e.whitby@sheffield.ac.uk)
Purpose: To describe the occurrence of intradural (IDH) and subdural (SDH)
hemorrhage in pediatric and perinatal deaths using a combined approach with
autopsy, histology and post mortem magnetic resonance (PM MRI).
Methods and Materials: Retrospective review of the post mortem examination and
PM MRI findings in the central nervous system of 42 cases. The MRI was conducted
with a 1.5 T magnet with fast spin-echo T2 weighted images. The gross dissection
of the brain was performed using a posterior approach. The brain and spinal cord
were fixed in 20% buffered formalin at 37° for 4 to 6 days before histology.
Results: Acute hypoxia was present in 14/42 cases on the histology and the PM
MRI. IDH was identified by histology in 35 cases: diffuse in 17 and focal in 18
cases. 12/17 cases with diffuse IDH were less than a week old. IDH was either
more prominent or only present in the posterior falx and tentorium. Eleven cases
(all with diffuse IDH on histology and 10 with features of hypoxia on histology and
at PM MRI) had a small SDH seen at autopsy and on PM MRI.
Conclusion: IDH is not an uncommon finding in the pediatric and perinatal post
mortem. When diffuse, IDH was frequently associated with hypoxia. In 12 of 17 cases
with diffuse IDH, there was also an SDH. Further studies are needed to confirm
the cause of our observed association among hypoxia, IDH and SDH hemorrhage
in children dying of natural causes.
B-530
11:51
A new image database on physiological brain iron accumulation in
pediatrics: An in vivo MR study using susceptibility-weighted phase
imaging
T. Nishiguchi, K. Mochizuki, Y. Inoue; Osaka/JP (tomokazu-n@med.osaka-cu.ac.jp)
Purpose: To better understand disease-related, excessive iron deposition in the
brain, it is necessary to know the physiological course of ferrous iron accumulation.
The purpose of this study was to establish baseline phase data for brain tissues
by susceptibility-weighted phase imaging (SWI-&).
Methods and Materials: Forty-four pediatric patients (M:F=32:12, range in age
0-22) were examined at 1.5 T using SWI-& (TR/TE/flip angle: 48/40/20; resolution:
0.7, *0.9, *1.6 mm). The regions evaluated were the both sides of motor cortex
(MC), putamen (PUT), globus pallidus (GP), caudate nucleus (CN), thalamus, (T),
substantia nigra (SN), red nucleus (RN) and dentate nucleus (DN). Phase shift data
were analyzed by age, gender, and hemispheric factors for each region using a
biochemical mixed linear model (BM).
Results: At birth, no accentuated phase shift due to iron was noted on SWI-&.
Positive phase shifts due to iron accumulation were first detected at 4.5, 37, 23,
56, 67, 35, 56, and 106 months in the MC, PUT, GP, CN, T, SN, RN, and DN, respectively. These were significantly earlier than those on spin-echo T2-weighted
images (SE-T2). There was no statistically significant effect by gender or the
hemispheric factors. A correlation between phase shifts and the BM suggest the
possibility of detecting iron below 5 mg/dl, a significantly lower level compared to
10 mg/dl on SE-T2.
Conclusion: SWI-& is highly sensitive for detecting physiological iron content in the
brain and would provide a new imaging baseline for disease-related iron deposition
and gray- and white-matter contrasts.
Scientific Sessions
10:30 - 12:00
Room L/M
Radiographers
SS 1014
Education and quality control
Moderators:
M. Golebiowski; Warsaw/PL
K. Knapp; Exeter/UK
B-531
10:30
A new model of trauma training and simulation for radiographer students
L.I. Hansen, I.-J. Aandahl, K.G. Vikestad, J.B. Dormagen; Oslo/NO (ilns@uus.no)
B-532
10:39
From harmonics to harmonisation: European ultrasound education
J. Dodgeon1, A. Sykes1, R. Ribeiro2, L. Lanca2, T. Johannesen3; 1Salford/UK,
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Lisbon/PT, 3Oslo/NO (jan.hugeon@virgin.net)
Purpose: The purpose of this study is to create awareness on the theory of
medical abdominal diagnostic ultrasound, to create awareness on the opportunities for advanced practice, to assist the teaching staff in developing their skills and
competencies and to develop provision within their own countries and to initiate
development of joint European courses.
Methods and Materials: The current usage of diagnostic ultrasound has created
a rising demand in training for ultrasound users. This, allied with a lack of uniformly
accepted standards, creates a potential problem for ensuring future operator competency and therefore accuracy of medical interventions. To help address these
problems, we developed a 2-week iIntensive programme supported by EU funding
from the lifelong learning programme, and aimed at postgraduate health-care practitioners from European countries with different approaches to ultrasound practice
and education. This ground-breaking course also offered the development of opportunities for staff members of the partner institutions, since joint course design
and delivery enable sharing of educators’ skills and competencies.
Results: The 2-week intensive programme was delivered at the University of Salford
in the UK and attended by students from the UK and from institutions in Norway,
Portugal, and Sweden. Overall, student evaluations were very positive; 100% felt
the course increased their knowledge of physics and the “core skills” for diagnostic
ultrasound, and most (77-92%) thought their knowledge and skills had improved.
Conclusion: The highly positive evaluations and outcomes of this project have
stimulated much interest across participant institutions and countries, and prove
the value of international healthcare education.
10:48
Tuning learning outcomes and competences for radiography courses in
Europe
A. Henner1, A. Vinorum2, V. Challen3, A. Vieira4; 1Oulu/FI, 2Oslo/NO, 3Lancaster/UK,
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Lisbon/PT (anja.henner@oamk.fi)
Purpose: Degree profiles in radiography vary throughout Europe, including requirements for first post-competencies arising from different national traditions and
ways in which the profession has developed. The Higher Education Network for
Radiography in Europe (HENRE), through the use of the tuning methodology, has
spearheaded recommendations and descriptors for radiography competencies and
learning outcomes for the first and second higher education tuning cycles.
Methods and Materials: An electronic questionnaire with rating scales for subjectspecific and generic competencies based on the results of the HENRE I project
was completed by academics, students and clinicians in European countries. A
number of other stakeholders were consulted, including radiography societies and
universities providing wide professional and educational experience.
Results: Recommendations for expected work loads expressed in ECTS for
first and second cycles with an explanation as to the differences between clinical
practice and clinical placement are made. The questionnaire (795 answers from
18 counries) showed that all specific competencies received scores higher than
2.96 (scale 0-4) for 1st cycle education with a high correlation among academics,
students and clinicians. Groups gave high scoring to competencies related to optimizing radiation dose management, informing and instructing patients appropriately
and team work. For generic competencies, the following were scored higher than
3.66 (scale 0-4) for all three groups showing a high correlation i.e. the capacity for
applying knowledge in practice and concern for quality
Conclusion: The tuning template for radiography provides recommendations for
expected workloads including scientific areas in the curriculum and the identification
of generic and subject competencies.
B-534
10:57
Self-assessment as a part of clinical audits in radiology
A. Henner, S. Mattila, M. Huovinen, A. Servomaa; Oulu/FI (anja.henner@oamk.fi)
Purpose: Radiological units in Finland have been audited once. Now, the second
audit cycle is going on. One of the key areas is self-assessment. The purpose of
this study is to point out by examples how to make self -assessment in radiological
X-ray departments as a part of clinical audits.
Methods and Materials: Radiographers and radiologists produce optimisation
of image quality and dose in several health centres as a part of everyday work.
Dose optimisation is done by different methods: by using programs of the equipments, by regulating the AEC (automatic expose control) and critically analysing
the use of grid.
Results: Self-assessment can be done by analysing own, present practices,
improving and testing them and by making a valid documentation. Digital imaging
technique offers a lot of possibilities to optimise dose and image quality e.g., in
digital mammography by using low dose technique instead of standard. In Lumber
spine lateral examination, 16% and in hip joint 27% dose decrease was achieved
by testing the AEC and using its possibilities (plus /minus) in a proper way. The
use of air gap (30 cm) instead of a grid in hip joint axio- lateral project decreased
skin dose by two-- thirds. PACS system offered opportunity to analyse the quality
of images afterwards.
Conclusion: Self-assessment is a part of everyday work. All members of the staff
as a team should do it regularly, in different areas. It is useful, gives new ideas and
offers a possibility to develop the quality of your own department.
B-535
11:06
The role of clinical assessment in radiography education across Europe
M.D.J. Davis; Dublin/IE (michaela.davis@ucd.ie)
Purpose: Explore the role of clinical asessment in radiography education across
Europe.
Methods and Materials: To identify if there is a clinical assessment system in
place. To identify whether such a system is formal or informal. If it is formal, how
does it impact on the students exit qualification. To identify who undertakes the
assessment and if they are trained for the role. The aim of this investigation was to
identify the role of clinical assessment in radiography education across Europe. A
questionnaire was devised by members of the subgroup and placed on the HENRE
website. Higher education institutions (HEIs) offering courses in radiography across
Europe were requested to access the website and complete the questionnaire.
Results: A total of 27 replies were received and analysed. The results demonstrated
that all students undertake a formal system of clinical assessment of their practice
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Purpose: To measure the learning effect of trauma simulation training for radiographer students.
Methods and Materials: A 2.5-day long trauma course was tailored for 46 third year
radiographer students from the local University College. We involved experienced
professionals in lectures and practical training. In the simulation centre of a major
Scandinavian trauma hospital, a realistic trauma scenario was presented for each
group of two students. The students were set tasks related to various difficulties:
acquisition was disturbed, exposure was inferior, organs were cut on the film, patient
was getting unstable and the team leader was getting impatient. X-ray exposure
was simulated and samples of acquisition failures were demonstrated. Debriefing
with a positive focus was performed afterwards. A questionnaire (1-no agreement
to 5-thorough agreement) on the evaluation of the course relevance, trauma understanding, the students’ self-evaluation and the teachers’ ability to encourage the
students was filled up. The control group consisted of 19 radiographer students who
had undergone standard trauma education at another radiographer college.
Results:The comparison between the trauma simulation group and the control
group revealed significant differences in rating the relevance of the trauma education (4.8 versus 2.4), the educational contributions to trauma understanding (4.7
versus 2.6), the self-evaluation of being part of the trauma team (3.7 versus 2.0)
and the teachers’ ability to encourage the students to learn more about trauma
(4.3 versus 1.9, all P 0.001).
Conclusion: Trauma simulation training for radiographer students revealed a
considerable learning effect. This concept should be integrated into standard
radiographer education programs.
B-533
Scientific Sessions
in order to determine if they are competent to practice. This followed a period of
clinical practice which ranged from 385 hours to 2400 hours. All institutions had
a system of assessment which the student has to pass to be able to practice in
radiography. There was a wide range of marks awarded for clinical assessment
which contributed to their qualification. This ranged from 0% up to 50% of the
award. Clinical assessments were undertaken by trained assessors in the vast
majority of cases (93%). These assessors were from both the clinical department
and academic institutions in almost equal proportion.
Conclusion: All students undertook a formal clinical practice assessment as a
requirement to practice once qualified. The range of hours for their clinical experience was vast ranging from 385 to 2400 hours. Ninety-three percent of all assessors
were trained for their role by a formal system of training and the assessment role
was undertaken by both clinical and academic staff in equal proportions.
B-536
11:15
Common assessment scheme for undergraduate radiographers in the
north of England
K.G. Holmes1, S. Boynes2, C. Sloane1, A. Westmoreland3, N. Crohn3,
A. Newton-Hughes4, A. Hyatt5, M. Elkington5, H. Robinson6; 1Lancaster/UK,
2
Bradford/UK, 3Leeds/UK, 4Salford/UK, 5Sheffield/UK, 6Preston/UK
(ken.holmes@cumbria.ac.uk)
Purpose: In 2006, the Northern Group of Universities delivering undergraduate
education met to discuss the assessment of students’ clinical skills in the hospital
environment. It was decided that the system at all universities could be improved
and a common assessment ‘tool’ should be devised to improve this element of
clinical assessment.
Methods and Materials: Programme leaders and clinical coordinators from universities met to discuss the value and efficacy of their undergraduate workplace clinical
assessment tool. It was decided that most of the current tools used had areas for
development to enable them to better discriminate clearly between students who
were safe to practice and those who were not. Over a period of 18 months, an assessment tool was developed to assess the student’s safe and proficient practice
in the workplace. The tool was refined at two regional meetings where delegates
from the participating universities, radiographic departments, service users and the
Strategic Health Authority were represented. After the initial pilot, the tool was refined
and will be re-evaluated.
Results: A common workplace assessment tool was devised, which is either being
piloted or adopted in seven universities in the North of England.
Conclusion: The presentation illustrates how universities can work collaboratively
to develop a common clinical skills assessment tool for radiography. The assessment tool has been well received by clinical staff and students and appears to be
a robust and effective tool for assessing the proficient practice of students in the
hospital environment.
B-537
11:24
The importance of feed-back due to the quality in radiographers’ image
production
K. Hillergård; Jönköping/SE (kerstin.hillergard@lj.se)
Purpose: Digitalisation of X-ray departments has influenced contact between radiologists and radiographers. The radiologist might even be situated in another country
making evaluation. Communication has been regarded important to obtain and
increase image quality. A fear has been presented among radiographers that lack
of feed-back might have negative consequences in image quality and knowledge
development. The aim of this paper is to find out whether feed-back is necessary
and how. This is a new research field. Much has been written about importance of
feed-back, however, not connected to radiographers and digitalisation.
Methods and Materials: A qualitative ethnographic approach is used. This method
is effective to investigate custom and silent knowledge. By using open-ended interviews and observations the possibilities to focus both in details and comprehensive
perspectives is possible. What are the objectives making the radiographer content
with the exam? Is feed-back given today, how and what is regarded necessary?
Results: Analyze was made by using Actors Network Theory. The result shows a
huge complex heterogeneous network regarding objectives of satisfaction. Communication with radiologist, colleagues and patient and also documentation and
feed-back is pointed out as important. The lack of communication and feed-back
from radiologists in the digital environment is expressed.
Conclusion: To engross knowledge it is necessary to have constantly recurring
personal feed-back. An electronic messenger system could be used as a supplementary tool for instant feed-back. Lacking radiologists, I recommend collegial
reviews. Building a system for this will be the topic of my next paper.
S262
A
B
C
D
E
F
G
F
H
B-538
11:33
Radiographer-acquired and radiologist-reviewed ultrasound examination:
Agreement with radiologist’s bedside evaluation
C. Tapper1, L. Thorelius2, A. Knutsson1, Ö. Smedby1; 1Linköping/SE, 2Herlev/DK
(carina.tapper@lio.se)
Purpose: A growing demand for ultrasound examinations and higher quality
requirements motivate searching for routines that combine the diagnostic accuracy of radiologist-performed examinations with the economical advantages
of sonographer-performed examinations. One possible approach is to use strictly
standardized acquisition and documentation schemes that give the radiologist
access to all the relevant information after the examination. A recently introduced
method (“standardized method”), combining acquisition by a radiographer, documentation as standardized cine-loops and review by a radiologist, was compared
with the formerly used routine (“traditional method”), where the diagnosis is made
bedside by the radiologist.
Methods and Materials: In 64 polyclinic patients, the kidneys (n = 27) or the
gallbladder (n = 37) was examined with both the standardized and the traditional
method. The off-line review was always made by a different radiologist than the
bed-side examination. The radiologist’s findings of hydronephrosis, tumours, cysts,
echogenicity and cortical thickness (in the kidneys) and wall thickness, concrements and polyps (in the gallbladder) were compared between the methods with
respect to agreement (proportion of agreement and kappa coefficient) as well as
systematic differences (McNemar test).
Results: The findings on kidney examination showed a median agreement between
the two methods of 87% (70-100 %; kappa = 0.68-1.0), and those on the gallbladder
examination showed an agreement of 94% (86-100%; kappa = 0.65-1.0). There
were no significant systematic differences between the methods.
Conclusion: The satisfactory agreement indicates that ultrasound examinations
performed by a radiographer and analyzed off-line by a radiologist may be an
alternative to bedside examinations by a radiologist.
B-539
11:42
Balancing diagnostic image quality with entrance dose and filtration in
computed radiography: An European perspective
T. Lehnert, M. Kissner, R. Hammerstingl, J.O. Balzer, M.G. Mack, T.J. Vogl;
Frankfurt a. Main/DE (thomas.lehnert@kgu.de)
Purpose: In this study, image quality was based on required clinical criteria, in
order to investigate to what degree entrance dose could be lowered and what
kind of added filtration can be used without impinging on radiologist confidence
levels in diagnosing.
Methods and Materials: Images were taken of extremities from a cadaver using
stepwise decreasing dose levels and variation of added filtration (no added filtration,
aluminum, aluminum/copper) under digital projection radiography (Kodak DirectView
CR950). Four radiologists were presented the images in a blinded fashion and rated
each with an image quality score from 1 to 9 indicated very satisfied and 1 as very
unsatisfied indicating loss of diagnostic value. Dose levels (DL) considered were
100, 75, 50 and 25% of the normal and customary X-ray techniques used for the
particular body part and projection.
Results: Without added filtration, image quality mean score was rated with 6.3 (DL
100%), 5.5 (DL 75%), 5.1 (DL 50%) and with 4.3 (DL 25%). An added aluminum
filtration induced an image quality mean score of 5.8 (DL 100%), 5.9 (DL 75%),
4.7 (DL 50%) and of 3.4 (DL 25%). Using aluminum/copper filtration, image quality mean score was rated with 5.9 (DL 100%), 5.8 (DL 75%), 4.6 (DL 50%) and
with 2.9 (DL 25%).
Conclusion: It is possible, in the case of extremities, to lower entrance doses up
to 75% of the normal value, a reduction of 25% in dose, under simultaneous use of
added aluminum or aluminum/copper filtration, without comprising the diagnostic
value required.
B-540
11:51
Image quality on breast MR: Comparison between linear and parallel
acquisition coils
M.P. Ribeiro, O. Fouto, C. Silva-Fortes, M.A. Correia; Lisbon/PT
(margarida.ribeiro@estesl.ipl.pt)
Purpose: A comparative study was delivered to assess the SNR and uniformity
on breast MR images with 2 different coil types. Both coils are dedicated to MR
mammography: a single loop linear bilateral surface coil and a parallel acquisition
by synergy phased array coil (4 elements) with SENSE algorithm.
Methods and Materials: A paired sample (20 image