Functional causes of the ductal obstructive pattern on hepatobiliary scans.

Hepatobiliary imaging with Tc-99m IDA derivatives has proven value for evaluation of biliary disease. Prompt hepatocellular uptake with persistent nonvisualization of the common bile duct and bowel is usually indicative of a high-grade common bile duct obstruction, but is not pathognomonic. A functional abnormality due to hepatocyte dysfunction resulting in intrahepatic cholestasis can also cause this pattern. Two cases of hepatocellular excretory dysfunction, one due to E. coli endotoxemia with intrahepatic cholestasis and the other due to acute hepatitis A that produces ductal obstructive patterns on Tc-99m disofenin scintigraphy in patients with documented patent biliary ducts, are reported. Transhepatic cholangiography or endoscopic retrograde cholangiography may be useful when the diagnosis of biliary ductal obstruction is in doubt.