Hepatobiliary scintigraphy in congenital cystic dilatation of biliary tract.

Six preoperative and five postoperative hepatobiliary scans in children having cystic dilatation of the biliary tract were analyzed. The preoperative hepatobiliary scans revealed three distinct patterns. The type 1 pattern showed, in early scans, good hepatic uptake of radioactivity, and photon deficient area(s) around the porta hepatis or in the subhepatic region. These area(s) showed progressive accumulation of radio activity in the delayed scans. The type 2 pattern revealed poor hepatic uptake, nonvisualization of major biliary channels, and photon deficient area(s) in the porta hepatis or subhepatic region which persisted throughout the study. Preoperatively, it was possible to diagnose cystic dilatation of biliary tract in cases that showed type 1 and type 2 patterns. No preoperative diagnosis was possible when the scans showed a type 3 pattern. Analysis of results revealed a correct pre-operative diagnostic rate of 83.3% for the cystic dilatation of biliary tract. It was also possible to provide correct functional information regarding the patency of the bile outflow tract in all 11 cases, both pre- and postoperatively, with a diagnostic rate of 100%. On the basis of the overall accuracy of results obtained in this series, hepatobiliary scintigraphy is strongly advocated in suspected cases of cystic dilatation of the biliary tract for the initial diagnosis and for the assessment of the status of the bilioenteric bypass postoperatively.