Objective: To study the correlation between the findings of hilar cholangiocarcinoma in hepatic arterial phase and portal venous phase. Attention will focus on whether the arterial phase imaging shows more detail than portal phase imaging.
Material and Method: Descriptive study design with retrospective data collection in Srinagarind Hospital, Khon Kaen University. CT scans of the upper abdomen of 34 patients with pathologically proven hilar cholangiocarcinoma between 2002 and 2004 were reviewed for: 1) characteristic of the tumor, 2) adenopathy, 3) arterial involvement, 4) venous involvement, and 5) degree of biliary involvement on both the hepatic arterial and portal venous phases.
Results: The correlation was high for characteristics of the tumor, the tumor enhancement pattern, and detection of adenopathy, degree of biliary involvement, and arterial involvement, but low for portal venous involvement which the portal venous phase detected better than the hepatic arterial phase.
Conclusion: In hilar type cholangiocarcinoma, the portal venous phase yielded the best findings. Furthermore, it showed all findings that were seen in the hepatic arterial phase. According to the present study, the authors suggest doing a pre-contrast study then a portal venous phase imaging for evaluation and diagnosis of hilar type cholangiocarcinoma. There is no necessity to perform hepatic arterial phase in hilar cholangiocarcinoma.

Keywords: Hilar cholangiocarcinoma, Helical CT, Portovenous phase