Magnetic resonance cholangiopancreatography in the preoperative assessment of patients with biliary pancreatitis.

Background: The ultimate treatment of acute biliary pancreatitis (ABP) is undoubtedly laparoscopic cholecystectomy, but controversy remains about the optimal imaging method in the preoperative assessment of these patients. In this study, we evaluated the usefulness of magnetic resonance cholangiopancreatography (MRCP) in detecting common bile duct (CBD) stones and associated pathologies in patients with ABP. At the same time, we tried to determine the natural transit time of gallstones from gallbladder to duodenum in ABP.

Methods: Between February 1999 and October 2006 a prospective observational study was conducted and 104 consecutive patients with ABP were recruited. MRCP findings were correlated with subsequent endoscopic retrograde cholangiopancreatography, endoscopic ultrasonography, intraoperative cholangiography or clinical follow-up.

Results: MRCP correctly predicted the presence of CBD stones in 19 out of 104 patients, and there were two false-positive and four false-negative results. The ability of MRCP to detect CBD stones was: positive predictive value 90.5%, negative predictive value 95.2%, sensitivity 82.6%, specificity 97.5% and overall accuracy 94.2%. MRCP performed within 48 h after admission showed CBD stones in 28.6% of the patients decreasing to 8.0% after 1 week. MRCP disclosed cholecystitis in 25 patients, anatomical variants of the cystic duct in 10 patients and a wide variety of other abnormalities of the upper abdominal cavity.

Conclusion: MRCP is highly accurate in the preoperative detection of CBD stones and other biliopancreatic pathologies in patients with gallstone pancreatitis.