Diagnostic value of magnetic resonance cholangiopancreatography to detect bile duct stones in acute biliary pancreatitis.

OBJECTIVES: This study aims to evaluate the diagnostic value of magnetic resonance cholangiopancreatography (MRCP) in detecting common bile duct (CBD) stones in acute biliary pancreatitis (ABP).

METHODS: The medical records of patients presenting with ABP from January 2008 to July 2013 were reviewed to assess the value of MRCP in detecting CBD stones in ABP. Endoscopic retrograde cholangiopancreatography (ERCP) was used as the reference standard to assess the diagnostic yield of MRCP in detecting choledocholithiasis. When ERCP was unavailable, intraoperative cholangiography or clinical follow-up was used as the reference standard.

RESULTS: Seventy-eight patients who underwent MRCP were diagnosed with ABP, and thirty of the 78 patients (38%) were confirmed to have CBD stones per the study protocol. The sensitivity of MRCP in detecting CBD stones in ABP was 93.3% compared to 66.7% for abdominal CT (P < 0.008). The overall accuracy of MRCP in detecting choledocholithiasis was 85.9% compared to 74.0% for abdominal CT (P < 0.041). The area under the receiver operating characteristic curve (AUC) of MRCP in detecting CBD stones was 0.882, which was more accurate than the AUC of 0.727 for abdominal CT (P = 0.039). In 38 patients who underwent ERCP, the sensitivity and negative predictive value of MRCP in detecting CBD stones were both 100% regardless of the dilatation of the bile duct (≥7 mm versus < 7 mm).

CONCLUSION: MRCP is an effective, noninvasive modality to detect CBD stones in ABP and can help identify patients who require ERCP.