Irie H, Honda H, Kuroiwa T, Yoshimitsu K, Aibe H, Shinozaki K, Masuda K. Pitfalls in MR cholangiopancreatographic interpretation. Radiographics 2001 Jan-Feb;21(1):23-37
Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. hiirie@dr.hosp.kyushu-u.ac.jp
Magnetic resonance (MR)
cholangiopancreatography (MRCP) is widely used in the evaluation
of pancreatobiliary disorders. However, numerous related pitfalls
may simulate or mask pancreatobiliary disease. Maximum-intensity-projection
(MIP) reconstructed images completely obscure small filling defects
and may demonstrate respiratory motion artifacts. T2 weighting
may vary with different MR imaging sequences and influence MRCP
findings. Incomplete imaging may create confusion regarding ductal
anatomy or disease. Furthermore, MRCP yields only static images
and thus may fail to depict various anomalies. Limited spatial
resolution makes differentiation between benign and malignant
strictures with MRCP alone extremely difficult. Susceptibility
artifacts may be caused by metallic foreign bodies or gastric-duodenal
gas. Fluid accumulation may produce a pseudolesion or pseudostricture,
although changing the imaging angle or section thickness may be
helpful. Pneumobilia may be misinterpreted as bile duct stones,
and true stones may be overlooked. Pulsatile vascular compression
can cause pseudo-obstruction of the bile duct. Use of both source
and MIP reconstructed images obtained from different angles can
help avoid cystic duct-related pitfalls. Repeat MRCP or conventional
MR imaging can help avoid pitfalls related to the periampullary
region. Segmental collapse of the normal main pancreatic duct
may be misinterpreted as stenosis, but administration of secretin
is helpful. An awareness of these pitfalls and possible solutions
is crucial for avoiding misinterpretation of MRCP images.
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