outer layer. Type 2 has two layers of ill-defined margin. Type 3 shows
multiple hyperintense cystic spaces in the wall. Type 4 shows diffuse
nodular thickening without layering. The MR findings of a layered pattern
of thickened gallbladder were well correlated with histopathology. Chronic
cholecystitis matched to Type 1, acute cholecystitis corresponded to Type 2,
adenomyomatosis showed Type 3, and the gallbladder carcinomas showed
Type 4. All four layered patterns were associated with a PPV of 73% or
greater, a sensitivity of 92% or greater, and a specificity of 95% or greater.
Our results indicate that MR findings of gallbladder wall thickening are
characteristic in each entity and correlate well with pathologic findings. The
classification of the layered pattern may be valuable for interpreting
thickened gallbladder wall.
Detection of common bile duct stones: Comparison between endoscopic
ultrasonography, magnetic resonance cholangiography, and
Kondo S, Isayama H, Akahane M, Toda N, Sasahira N, Nakai N, Yamamoto
N, Hirano K, Komatsu Y, Tada M, Yoshida H, Kawabe T, Ohtomo K, Omata
M (Department of Gastroenterology, University of Tokyo, 7-3-1 Hongo,
Bunkyo-ku, Japan). Eur J Radiol 2005:54:271– 275.
Objectives: New modalities, namely, endoscopic ultrasonography
(EUS), magnetic resonance cholangiopancreatography (MRCP), and helical
computed-tomographic cholangiography (HCT-C), have been introduced
recently for the detection of common bile duct (CBD) stones and shown
improved detectability compared with conventional ultrasound or computed
tomography. We conducted this study to compare the diagnostic ability of
EUS, MRCP, and HCT-C in patients with suspected choledocholithiasis.
Methods: Twenty-eight patients clinically suspected of having CBD stones
were enrolled, excluding those with cholangitis or a definite history of
choledocholithiasis. Each patient underwent EUS, MRCP, and HCT-C prior
to endoscopic retrograde cholangio-pancreatography (ERCP), the result of
which served as the diagnostic gold standard.
Results: CBD stones were detected in 24 (86%) of 28 patients by ERCP/
IDUS. The sensitivity of EUS, MRCP, and HCT-C was 100%, 88%, and
88%, respectively. False negative cases for MRCP and HCT-C had a CBD
stone smaller than 5 mm in diameter. No serious complications occurred,
while one patient complained of itching in the eyelids after the infusion of
contrast agent on HCT-C.
Conclusions: When examination can be scheduled, MRCP or HCT-C will
be the first choice because they were less invasive than EUS. MRCP and
HCT-C had similar detectability but the former may be preferable
considering the possibility of allergic reaction in the latter. When MRCP
is negative, EUS is recommended to check for small CBD stones.
Diagnostic accuracy of MRCP in choledocholithiasis
Guarise A, Baltieri S, Mainardi P, Faccioli N (Via Vaioi 2, I-37020
Gargagnago (VR), Italy). Radiol Med 2005;109:239 –251.
Purpose: The aim of this study was to evaluate the accuracy of MRCP in
diagnosing choledcholithiasis considering endoscopic retrograde cholan-
giopancreatography (ERCP) as the gold standard. To compare the results
achieved during the first two years of use (1999–2000) of magnetic
resonance cholangiopancreatography (MRCP) in patients with suspected
choledocholithiasis with those achieved during the following two years
(2001– 2002) in order to establish the repeatability and objectivity of
Materials and methods: One hundred and seventy consecutive patients
underwent MRCP followed by FRCP within 72 h. In 22/170 (13%)
patients, ERCP was unsuccessful for different reasons. MRCP was
performed using a 1.5 T magnet with both multislice HASTE sequences
and thick-slice projection technique. Choledocholithiasis was diagnosed in
the presence of signal void images in the dependent portion of the duct
surrounded by hyperintense bile and detected at least in two projections.
The MRCP results, read independently from the ERCP results, were
compared in two different and subsequent periods.
Results: ERCF confirmed choledocholithiasis in 87 patients. In these cases,
the results of MRCP were the following: 78 true positives, 53 true
negatives, 7 false positives, and 9 false negatives. The sensitivity,
specificity, and accuracy were 90%, 88%, and 89%, respectively. After
the exclusion of stones with diameters smaller than 6 mm, the sensitivity,
specificity, and accuracy were 100%, 99%, and 99%, respectively. MRCP
accuracy was related to the size of the stones. There was no significant
statistical difference between the results obtained in the first 2-year period
and those obtained in the second period.
Conclusions: MRCP is sufficiently accurate to replace ERCP in patients
with suspected choledocholithiasis. The results are related to the size of
stones. The use of well-defined radiological signs allows good diagnostic
accuracy independent of the learning curve.
Imaging evaluation of the postoperative knee ligaments
Haslan H, Sundaram M, Miniaci A (Department of Radiology, A21
Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195). Eur J Radiol
Until the advent of magnetic resonance imaging (MRI), the evaluation of
ligament reconstruction of the knee was largely based on clinical
examination and radiographs. MRI is the modality of choice for
noninvasive evaluation of reconstructed ligaments, menisco-capsular
structures, and soft tissues. This article reviews the surgical techniques,
normal and abnormal appearances of the ACL and PCL grafts, and
common complications following ligament reconstruction.
A comparative evaluation of a RARE-based single-shot pulse sequence
for diffusion-weighted MRI of musculoskeletal soft-tissue tumors
Dietrich O, Raya JG, Sommer J, Deimling M, Reiser MF, Baur-Melnyk A
(Department of Clinical Radiology-Großhadern, Ludwig Maximilian
University of Munich, Marchioninistrasse 15, D-81377 Munich, Germany).
Eur Radiol 2005;15:772 – 783.
The purpose of this study was to evaluate the feasibility of a centric-
reordered modified rapid acquisition with relaxation enhancement
(mRARE) sequence for single-shot, diffusion-weighted magnetic resonance
imaging (DWI) of soft-tissue tumors in the musculoskeletal system. In the
evaluation of this sequence, DWI was performed in a liquid phantom, in
excised human tumor samples embedded in bovine muscle, and in nine
patients suffering from different types of soft-tissue tumors. The measure-
ments were compared with DWI using a spin-echo sequence and a single-
shot echo planar imaging (EPI) sequence. The phantom measurements in
water and dimethyl sulfoxide showed a difference of less than 5% when
comparing the apparent diffusion coefficients (ADCs) determined by the
mRARE sequence and the two other techniques. Comparing mRARE and
EPI, the differences in the ADCs were about 10% in the excised tumor
tissue and typically about 15% in vivo. ADCs between 0.8
/s, depending on the tumor type, were found in solid tumor
tissue; in cystic tumor areas, ADCs greater than 2.0
determined with the mRARE and the EPI sequences. Diffusion-weighted
images of the mRARE sequence were less distorted than those acquired
with the single-shot EPI sequence and provided more anatomic information,
because the muscle and fat signals were considerably higher.
Imaging of the postoperative meniscus
Toms AP, White LM, Marshall TJ, Donell ST (Department of Radiology,
Norfolk and Norwich University Hospital, Colney Lane, Norwich, Norfolk
NR4 7UY, UK). Eur J Radiol 2005;54:189–198.
Considerable developments have occurred in meniscal surgery and,
consequently, in the imaging of postoperative menisci, over the last
Abstracts / Journal of Clinical Imaging 29 (2005) 373–377 375