Role of hepatobiliary scintigraphy in biliary ascariasis

Following the introduction of immunodiacetic acid (IDA) compounds labelled with 99Tcm, hepatobiliary scintigraphy has successfully been used to identify a variety of hepatobiliary pathologies. This study deals with the scintigraphic findings in patients having involvement of the hepatobiliary system with ascariasis. Patients clinically suspected of having hepatobiliary pathology were routinely sent for radionuclide evaluation of the hepatobiliary system. 99Tcm HIDA, EHIDA or BULLIDA was injected under the gamma camera and one min frames were collected for 40 min over the abdominal region using an on-line computer. After the sequential study was over, if the gallbladder was not visualized, late pictures were taken until the gallbladder was seen or for 4 hours, whichever was earlier. When the gallbladder was visualized, post-fatty-meal images were made for visual analysis and time/activity curves were generated over regions of interest for further evaluation. Patients having total or partial subhepatic biliary channel obstruction with or without dilatation of intrahepatic ducts were subjected to endoscopic retrograde cholangio-pancreatography (ERCP) within the next two to three days. Out of 360 patients thus evaluated, 84 (23%) showed partial, total or near total subhepatic obstruction. In 55 cases the whole biliary tree was dilated; in 17 cases the left hepatic duct and the common bile duct (CBD); in seven cases the left hepatic duct alone, and in five cases the CBD alone. ERCP findings were concurrent in most cases. However, in 13 cases no abnormality of the biliary tree could be detected by ERCP, although worms were found in the duodenum. In 28 cases single or multiple worms were found inside the hepatobiliary channel. Video recordings of the ERCP revealed in some cases that the worms were moving in and out of the biliary channel. In 41 cases of proven biliary ascariasis, scintigraphic finding was indicative in all cases. Hepatobiliary scintigraphy appears to be a useful method in the diagnosis of biliary ascariasis. (author). 8 refs, 4 tabs