HILAR CHOLANGIOCARCINOMA - THIN-SECTION SPIRAL CT FINDINGS WITH CHOLANGIOGRAPHIC CORRELATION

Hilar cholangiocarcinoma, a highly lethal tumor, is difficult to diagn ose with conventional computed tomography (CT) because of its small si ze. Spiral CT allows more effective evaluation of these small lesions and better demonstrates the status of the hepatic arterial or portal v enous circulation. Among 27 patients with hilar cholangiocarcinoma (in filtrative in 21, exophytic in two, polypoid in one, diffuse in three) , thin-section spiral CT allowed identification of each tumor as an ar ea of focal wall thickening that obliterated the lumen. Seventeen of t he infiltrative tumors (81%) showed high attenuation. Identification o f the level of biliary obstruction was possible in 63% of the patients (17 of 27). The level of obstruction was underestimated in six patien ts and overestimated in four. Spiral CT is a valuable method for diagn osis of hilar cholangiocarcinoma; however, spiral CT is less accurate in evaluation of intraductal tumor extent because of the limited z-axi s resolution.