Extrahepatic biliary obstruction: Magnetic resonance imaging compared withendoscopic ultrasonography

Background and Study Aims: The aim of this study was to compare prospective ly the diagnostic efficacy of magnetic resonance (NIR) imaging and endoscop ic ultrasonography (EUS) in extrahepatic biliary obstruction. Patients and Methods: A total of 50 patients with suspected benign or malig nant extrahepatic biliary obstruction underwent MR imaging, including MR ch olangiopancreatography, and EUS, within a median time delay of 1 day. The f inal diagnosis was established by endoscopic retrograde cholangiopancreatog raphy in 37 cases, intraoperative cholangiography in nine cases, and clinic al and biochemical follow-up in four cases. Results: In total, 33 patients had extrahepatic biliary obstruction, of ben ign origin in 21 cases and of malignant origin in 12 cases, whereas 17 had no evidence of obstruction, The sensitivity and specificity of MR imaging w ere 91 % and 94 %, respectively. There were one false-positive and three fa lse-negative results, all related to choledochal sludge. The corresponding values for EUS were 97 % and 88 %, There were two false-positive results an d one false-negative result. False-positive diagnoses were related to the p resumed presence of biliary sludge and choledocholithiasis, whereas the fal se-negative diagnosis occurred in one patient with a final diagnosis of slu dge. No significant difference in sensitivity and specificity was observed between the two imaging methods (P > 0.05), Conclusion: In our study MR imaging was as accurate as EUS in the diagnosis of extrahepatic biliary obstruction.