Enhancement characteristics of cholangiocarcinomas on mutiphasic helical CT: emphasis on morphologic subtypes

Abstract

PURPOSE: The purpose of this study was to characterize the differences in CT enhancement pattern among the morphologic subtypes of cholangiocarcinomas. MATERIALS AND METHODS: Unenhanced, hepatic arterial (HAP), and portal venous phase (PVP) CT images of 84 patients with pathologically proven cholangiocarcinoma were retrospectively reviewed. Tumors were of the following types: 27 mass-forming, 39 periductal-infiltrating, and 18 intraductal. The CT attenuation values of tumors were measured at each phase. The tumor enhancement ratio (ER) on HAP and PVP was calculated. RESULTS: Each cholangiocarcinoma subtype produced characteristic enhancement relative to liver on HAP and PVP images: mass-forming tumors demonstrated hyperenhancing periphery and hyopenhancing centers; periductal-infiltrating tumors, hyperenhancing; and intraductal tumors, hypoenhancing. The ER of the tumor types was significantly different (P<.001, HAP, PVP): periductal-infiltrating tumors showed the highest ER (2.5; 3.8); the centers of mass-forming tumors, lowest (1.5; 2.2); the peripheries of mass-forming tumors, high (2.1; 3.0); intraductal tumors, low (1.9; 2.6). CONCLUSION: Cholangiocarcinoma subtypes tended to exhibit distinct enhancement characteristics. Knowledge of these enhancement patterns may aid diagnosis and surgical planning.