Biliary scintigraphy with DISIDA

Demonstration of bile duct patency using radionuclides is often an essential investigation in distinguishing extrahepatic biliary atresia from intrahepatic disease causing severe cholestasis. The improved results from portoenterostomy for biliary atresia, particularly if performed in the first 2 months of life,' together with the deleterious effect of inappropriate laparotomy and biliary surgery for infants with hepatic disease,2 make early accurate diagnosis essential. Difficulties with the 1311 Rose-Bengal faecal excretion test, which requires a 72 hour stool collection, have prompted consideration of new isotope excretion tests. Iminodiacetic acid (IDA) compounds are rapidly removed from the circulation by the liver and excreted in bile and, when labelled with 99mtechnetium, the biliary-intestinal excretion may conveniently be shown with a gammacamera. A new IDA compound, diisopropyl IDA (DISIDA) with improved lipid solubility allowing hepatic uptake at a high serum bilirubin concentration and with a shorter hepatobiliary transit time, has theoretical advantages over earlier IDA compounds, which often fail to distinguish biliary atresia from hepatic disease.3 We report an assessment of the value of DISIDA scintigraphy in 50 consecutive infants investigated because of conjugated hyperbilirubinaemia in the first 12 weeks of life.