Disparate dilatation of the intrahepatic and extrahepatic bile ducts in surgical jaundice.

Intrahepatic biliary dilatation on ultrasound has been reported as an early sign of biliary obstruction. This paper reports 12 patients with extrahepatic biliary obstruction in whome the extrahepatic biliary system was increased in caliber despite a normal appearance of the intrahepatic ducts. The bile ducts in all of these patients were evaluated with ultrasound and percutaneous transhepatic cholangiography. Computed tomography was performed in one case. The causes of obstructive jaundice included stricture, choledocholithiasis, and neoplasm. The common bile duct provides a sensitive indicator of biliary obstruction, and its demonstration by noninvasive or invasive means is mandatory even when the intrahepatic ducts appear to be normal.