Prospective evaluation of magnetic resonance cholangiography in patients with suspected common bile duct stones before laparoscopic cholecystectomy.

OBJECTIVE: To evaluate the predictive value of magnetic resonance cholangiography (MRC) in selected patients before laparoscopic cholecystectomy (LC).

METHODS: Patients with risk factors for common bile duct (CBD) stones scheduled for elective LC from March 1999 to May 2001, underwent MRC followed by endoscopic retrograde cholangiography (ERC) to detect the stones and the accuracy of MRC. Selection of suspected patients was based on clinical, ultrasonographic, and laboratory criteria.

RESULTS: During a 26-month period, a total of 267 patients were studied. Seventy-eight MRC identified patients were found to have CBD stones by ERC or laparoscopic cholangiography in the study. Seven of 78 patients were misdiagnosed as having CBD stones by MRC. In this study, MRC had a sensitivity of 100%, a specificity of 96.3%, a positive predictive value of 91.8%, and a negative predictive value of 100% for the detection of common bile duct stones.

CONCLUSIONS: With the use of LC, ERC is frequently performed before LC to detect CBD stones; but it is invasive with a well-documented complication rate. MRC is a simple non-invasive method for preoperative screening for CBD stones in at-risk patients. In this study if ERC had been limited to patients with a positive MRC, it would have reduced the need for ERC by 68.2%, and the complications of preoperative examination would be minimized significantly.