Capability of CT body scanning and ultrasonography to demonstrate the status of the biliary ductal system in patients with jaundice.

The capability of ultrasonography and computed tomographic body scanning to demonstrate the status of the biliary tract was studied prospectively in 23 jaundiced patients. Ultrasonography correctly indicated the presence or absence of obstruction in 21 of the 23 patients and CT scanning in 20. Both procedures correctly demonstrated no evidence of ductal dilatation in the five patients who had nonobstructive jaundice. Retrospective study of the same material increased the accuracy of CT scanning (22 of 23 patients) because of recognition of common bile duct dilatation in the absence of intrahepatic duct dilatation. The accuracy of ultrasonography was unchanged.