[CT and MR imaging differences between intrahepatic cholangiocarcinoma and hepatocellular carcinoma with invasions to billary tracts].

Objective: To identify the CT and MR imaging differences between intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC) with invasions to biliary tracts.

Methods: Eighteen patients with ICC and 32 HCC patients with invasions to biliary tracts confirmed by postoperative pathological diagnosis were enrolled in the study. All of the patients underwent CT or MR examinations. The image features about the tumor and the biliary tracts were analyzed retrospectively.

Results: The imaging features of ICC were: faint rim-like enhancement and no enhancement of the masses. The ICC invasions to biliary tracts were shown as severe dilation of biliary tracts, coarse-to-fine or separation of dilated tracts, thickened and enhanced walls, dilation of biliary tract encased in the mass. The HCCs showed quick fill-in and wash-out of the contrast media in the mass. The imaging features of HCC with invasions to biliary tracts were: mild dilated tracts, compressed and extruded tracts, thickening of the wall of dilated tracts and enhancement of the walls. The location of the dilated tracts were mostly alongside of the tumors. The chi square tests revealed significant differences between ICC and HCC in the above features (P<0.05).

Conclusion: CT or MR imaging may help differentiate ICC and HCC with invasions to biliary tracts.