Hepatobiliary scanning using 99mTc-pyridoxylideneglutamate

Abstract

Technetium 99m-pyridoxylideneglutamate ( 99mTc-PG) administered intravenously is excreted by hepatocytes into the bile canaliculi and enters the gallbladder through the cystic duct and, consequently, can be used for scanning the hepatobiliary ductal system. A total of 166 patients representing 27 normal subjects, 84 patients referred for investigation of pain in the upper right quadrant of the abdomen, and 55 jaundiced patients were evaluated with 99mTc-PG. In normal human volunteers, the agent reached the liver in five minutes, and the common bile duct, gallbladder, and duodenum within 15 minutes. Satisfactory images of the hepatobiliary tract were obtained using small dosages of 99mTc-PG. The gallbladder was not visualized when the cystic duct was occluded. In the presence of acute cholecystitis, cystic duct obstruction, or in chronic cholecystitis where other roentgenographic studies showed a nonfunctioning gallbladder, there was no concentration of 99mTc-PG in the gallbladder. In partial common bile duct obstruction a distended common bile duct was visualized along with delay in transit of radioactivity into the duodenum. Complete common bile duct obstruction was associated with no radioactivity in either the biliary or the gastrointestinal tracts up to 24 hours after injection. Hepatocellular disease was characterized by delayed liver clearance and delayed visualization of biliary and gastrointestinal tracts. 99mTc-PG scanning proved capable of differentiating between hepatocellular disease and extrahepatic biliary tract obstruction.