Hilar cholangiocarcinoma: Value of high-resolution enhanced magnetic resonance imaging for preoperative evaluation.

ABSTRACT

OBJECTIVES: The objective is to assess the accuracy of high-resolution (HR) enhanced magnetic resonance imaging (MRI) images in the preoperative evaluation of biliary and vascular invasion in hilar cholangiocarcinomas. METHODS: This retrospective study included 36 patients with hilar cholangiocarcinoma who underwent enhanced HR-MRI with an effective section thickness of 1.2 mm at 3.0 T before surgery. Combined HR-MRI and magnetic resonance cholangiopancreatography (MRCP) images were compared with MRCP in evaluating the extent of biliary infiltration according to the Bismuth-Corlette classification. To determine the suitable criterion for HR-MRI in predicting vessel invasion, Labeling 180 and 90 of circumferential contact of the tumor with the vessel were used to predict the invasion. The correlation between imaging findings and surgical and histopathological records was statistically analyzed. RESULTS: The accuracy in detecting biliary neoplastic invasion was higher for combined HR-MRI images (97.2%) than MRCP images (86.1%). HR-MRI images increased the accuracy in delineation of the tumor biliary extent (P < 0.05). The accuracy of Labeling 90 (98.6% in portal venous system and 98.0% in hepatic arterial system) was higher than that of Labeling 180 (96.5% in portal venous system and 94.6% in hepatic arterial system). However, there was no significant statistic difference between them (P > 0.05). Interobserver agreement was high with respect to biliary tract, portal venous, and hepatic arterial system involvement. CONCLUSIONS: Enhanced HR-MRI images showed excellent capability for assessing tumor extent and vascular invasion in hilar cholangiocarcinomas. More than 90° of circumferential contact of the tumor with the vessel on HR-MRI may be an appropriate criterion for predicting invasion.