Radionuclide cholescintigraphy in patients with suspected biliary tract obstruction

Radionuclide cholescintigraphy is used to help establish the diagnosis of acute cholecystitis and is thought to provide additional information regarding the patency of the biliary duct system. Nonvisualization of the extrahepatic biliary duct system and lack of excretion into the duodenum despite uptake in the liver (a positive study) is considered indicative of common bile duct obstruction. The authors retrospectively reviewed 281 hepatobiliary cholescintigrams done at Stamford Hospital from July 1, 1987 to June 30, 1989. Previous authors have demonstrated a false-positive rate of eight to 15 per cent in those cases that have a documented normal extrahepatic biliary system at operation. Of those patients explored after a common bile duct obstruction pattern depicted by cholescintigram in the authors' series, 46 per cent of patients were found to have normal extrahepatic biliary systems. Factors possibly contributing to this high false-positive rate are discussed. The utility of radionuclide hepatobiliary scans may be limited for diagnosis of biliary duct obstruction.