Differentiating combined hepatocellular and cholangiocarcinoma from mass‐forming intrahepatic cholangiocarcinoma using gadoxetic acid‐enhanced MRI

Abstract

To examine the differential features of combined hepatocellular and cholangiocarcinoma (HCC-CC) from mass-forming intrahepatic cholangiocarcinoma (ICC) on gadoxetic acid-enhanced MRI. Forty patients with pathologically proven combined HCC-CC (n = 20) and ICCs (n = 20) who had undergone gadoxetic acid-enhanced MRI were enrolled in this study. MR images were analyzed for the shape of lesions, hypo- or hyperintense areas on the T2-weighted image (T2WI), rim enhancement during early dynamic phases, and central enhancement with hypointense rim (target appearance) on the 10-min and 20-min hepatobiliary phase (HBP). The significance of these findings was determined by the χ(2) test. Irregular shape and strong rim enhancement during early dynamic phases, and absence of target appearance on HBP favored combined HCC-CCs (P < 0.05). Lobulated shape, weak peripheral rim enhancement, and the presence of complete target appearance on the 10-min and 20-min HBP favored ICCs (P < 0.05). However, 10 CC-predominant type of combined HCC-CC showed complete or partial target appearance on 10-min HBP. The shape of tumors, degree of rim enhancement during early dynamic phases, and target appearance on HBP were valuable for differentiating between combined HCC-CC and mass-forming ICC on gadoxetic acid-enhanced MRI.