Comparison of diffuse hepatocellular carcinoma and intrahepatic cholangiocarcinoma using sequentially acquired gadolinium-enhanced and Resovist-enhanced MRI

Purpose: The purpose of this study was to compare MRI findings of diffuse hepatocellular carcinoma (D-HCC) and intrahepatic cholangiocarcinoma (IHC) to identify characteristics of each. Materials and methods: We retrospectively analyzed MRI that consisted of unenhanced T1- and T2-weighted image, gadolinium (Gd)-enhanced dynamic image, and sequentially acquired Resovist-enhanced image from 29 patients with D-HCCs and 32 patients with IHC. Results: On T2-weighted imaging, D-HCCs usually appeared as poorly defined, infiltrative mildly hyperintense masses, whereas IHC appeared as well-defined, lobulated mildly hyperintense masses with areas of strong hyperintensity and hypointensity. On dynamic- and Resovist-enhanced T1-weighted MRIs, D-HCCs appeared as hypovascular and homogeneously hypointense or isointense masses with internal reticulation, whereas IHD appeared as centripetal enhancing masses with or without delayed central hyperintensity. Biliary dilatation was predominantly observed in the area adjacent to the IHC and in the intratumoral area of D-HCC. Portal venous tumor thrombus was observed in most of the D-HCC, and portal vein encasement was seen in 17 of the IHC. Conclusion: D-HCC and IHC exhibited characteristics of each at T1- and T2-weighted imaging, Gd-enhanced dynamic imaging, and sequentially acquired Resovist-enhanced T1-weighted imaging.