Sensitivity of ultrasound in the detection of biliary tract obstruction.

In 28 patient with varying degrees of biliary obstruction, the ultrasonic findings were correlated with the serum bilirubin levels and with the size of the bile ducts as measured by percutaneous transhepatic cholangiography (PTC). With ultrasound, study of the intrahepatic ducts achieved the greatest accuracy (71%); examination of common bile ducts and the gallbladder were found to be less sensitive (54 and 53%). Ultrasound proved to be very accurate in biliary obstruction, when the serum bilirubin was above 4.8 mg/100 ml (80 mumol/1).