The diagnostic accuracy of computed tomography in obstructive biliary disease: a comparative evaluation with direct cholangiography.

Computed tomography (CT) and direct cholangiography were performed in 75 patients for the evaluation of obstructive biliary disease. The two modalities correlated well in cases of moderately or severly dilated intrahepatic bile ducts that showed tortuosity and/or engorgement, but mild dilatation with stretching of theperipheral intrahepatic bile ducts that was seen with direct cholangiography was detected with CT in only one of nine patients. Consequently, the CT diagnosis was correct in 41 of 51 patients (80.4%) with obstructive biliary disease; however, CT was correct in only 15 of the 25 patients (60%) with nontumorous obstructive biliary disease. It is concluded that, in cases of clinically suspected nonneoplastic obstructive disease, percutaneous transhepatic cholangiography or endoscopic retograde cholangiopancreatography should be performed even when dilated ducts are not demonstrated by CT.