Ultrasonic evaluation of common bile duct stones: prospective comparison with endoscopic retrograde cholangiopancreatography.

Ultrasound is the modality of choice for the diagnosis of cholelithiasis and for the evaluation of the intra- and extrahepatic biliary tree in the patient with jaundice, but its role in the diagnosis of choledocholithiasis is less certain. We prospectively examined 90 patients who were to undergo endoscopic retrograde cholangiopancreatography (ERCP) by performing right upper quadrant sonography immediately prior to ERCP. We assessed the size of the intra- and extrahepatic ducts and the presence or absence of calculi. ERCP, which was successfully performed in 77 of 94 attempted examinations, percutaneous transhepatic cholangiography, or surgical follow-up composed the diagnostic standard for comparison. Ultrasound was not accurate in the diagnosis (sensitivity, 25%) or exclusion (value of a negative study, 73%) of choledocholithiasis. Furthermore, in the postcholecystectomy patient population, ultrasound assessment of biliary duct size is not a useful predictor of biliary disease. For symptomatic postcholecystectomy patients, we recommend ERCP as the initial diagnostic modality.