Evaluation of magnetic resonance cholangiography in the management of bileduct stones

Hypothesis: Magnetic resonance cholangiography (MRC) offers the potential f or accurate, noninvasive detection of common bile duct stones (CBDSs) befor e cholecystectomy, and for a consequent reduction in the incidence of preop erative negative diagnoses associated with endoscopic retrograde cholangiog raphy (ERC). Design: Prospective cohort study: MRC results were correlated with ERC (hig h-risk patients) or intraoperative cholangiography (moderate-risk patients) . Setting: A university hospital providing primary, secondary, and tertiary c are. Patients: Seventy patients with suspected CBDSs scheduled to undergo electi ve cholecystectomy between April 15, 1997,and September 30, 1998. Forty pat ients were considered at high risk and 30 at moderate risk for CBDSs, accor ding to results of liver function tests and sonograms of the upper abdomen. Main Outcome Measures: Confirmation or exclusion of CBDSs by MRC was assess ed by a panel of radiologists who were unaware of the ERC. results. Results of ERC and intraoperative cholangiography were analyzed by the investigati ng gastroenterologists Dr surgeon. Results: Results of MRC were positive for CBDSs in 21 (52%) of 40 high-risk patients, a finding confirmed by preoperative ERC in 19(90%) of 21 patient s. Results of MRC were positive fur CBDSs in 6 (20%) of 30 moderate risk pa tients, all of which were confirmed by intraoperative cholangiography. Fina lly, CBDSs were present in 19 (48%) of 30 high-risk patients and 6 (20%) of 30 moderate-risk patients (P = .02). Overall sensitivity and specificity o f MRC were 100% and 95.6%, respectively; the positive and negative predicti ve values were 92.6% and 100%, respectively. Conclusions: Magnetic resonance cholangiography is a reliable, noninvasive method for the detection or exclusion of CBDSs, and seems to reduce the fre quency of negative diagnoses associated with ERC. Magnetic resonance cholan giography revealed no CBDSs in 19 (48%) of 40 patients at high risk for CBD Ss. Thus, MRC-based diagnosis has the potential to reduce the number of inv asive preoperative diagnostic procedures and their associated risks and ove rall health rare costs.