HEPATOBILIARY SCINTIGRAPHY IN CHILDREN

Hepatobiliary scintigraphy using iminodiacetic (IDA) radiopharmaceutic als provides clinically useful information on the function of the bili ary tract in a variety of pathological processes in children, includin g neonatal jaundice, gallbladder dysfunction, trauma, and liver transp lantation. Phenobarbital premedication (5 mg/kg per day for a minimum of 5 days in divided doses) is used in infants who are being examined for neonatal jaundice to increase the accuracy of Tc-99m-IDA scintigra phy in differentiating extrahepatic biliary atresia from neonatal hepa titis. Biliary atresia can be ruled out in an infant if a patent bilia ry tree is shown with passage of activity into the bower. If no radiop harmaceutical is noted in the bowel on imaging up to 24 hours, distinc tion between severe hepatocellular disease and biliary atresia cannot be made. The literature reports 91% accuracy, 97% sensitivity, and 82% specificity for hepatobiliary imaging in the diagnosis of biliary atr esia. The impairment of both intrahepatic and extrahepatic biliary dra inage is an important cause of liver disease in cystic fibrosis. Hepat obiliary scintigraphy in cystic fibrosis has shown characteristic patt erns of dilatation of mainly the left hepatic duct, narrowing of the d istal common bile duct, gallbladder dysfunction, and delayed bower tra nsit. Cholecystitis in children may be acalculous. Sensitivity and spe cificity for the scintigraphic diagnosis of acute acalculous cholecyst itis is reported to range from 68% to 93% and 38% to 93%, respectively . Cholescintigraphy in a suspected bile leak provides information gene rally not available with other techniques, except for direct cholangio graphy. If the amount of intraperitoneal accumulation of the tracer is greater than that entering the gastrointestinal tract, surgery is usu ally indicated. Hepatobiliary imaging in children who have undergone l iver transplantation will assess graft vascularity, parenchymal functi on, biliary drainage, presence of a leak, and obstruction. (C) 1996 hy W.B. Saunders Company