MR cholangiopancreatography versus endoscopic sonography in suspected common bile duct lithiasis: a prospective, comparative study.

OBJECTIVE: Our purpose was to compare the accuracy of MR cholangiopancreatography and endoscopic sonography for the diagnosis of common bile duct stones in patients with a mild to moderate clinical suspicion of common bile duct stones.

SUBJECTS AND METHODS: Forty-seven patients were prospectively enrolled. Inclusion criteria included acute pancreatitis, subclinical jaundice, and clinical features of common bile duct stone migration. Radial endoscopic sonography and MR cholangiopancreatography with the single-shot fast spin-echo technique were performed a maximum of 48 hr apart. The gold-standard diagnosis was obtained with ERCP (n = 20) or intraoperative cholangiography (n = 14) if the results of endoscopic sonography or MR cholangiopancreatography were abnormal or if a cholecystectomy was performed, or by clinical and biochemical follow-up (n = 11) if the results of endoscopic sonography and MR cholangiopancreatography were normal.

RESULTS: The final diagnosis was common bile duct stones in 16 patients, malignant obstructions in four, and another biliary disease in two (lithiasis migration aspect with papillary edema); 23 patients had no biliary disease. The sensitivity and specificity of MR cholangiopancreatography were, respectively, 90.5% and 87.5% for etiologic diagnosis and 87.5% and 96.6% for the detection of common bile duct stones. The corresponding values for endoscopic sonography were 86.4% and 91.3% for etiologic diagnosis and 93.8% and 96.6% for visualization of choledocholithiasis. Accuracy did not significantly differ between the techniques.

CONCLUSION: In cases of mild to moderate suspicion of choledocholithiasis, the accuracies of endoscopic sonography and MR cholangiopancreatography are similar. Because MR cholangiopancreatography is noninvasive, it may be preferred for this indication.