MRI of small intrahepatic mass-forming cholangiocarcinoma and atypical small hepatocellular carcinoma (≤3 cm) with cirrhosis and chronic viral hepatitis: a comparative study

Objective: The objective was to identify the decision-making magnetic resonance (MR) features in differentiating small intrahepatic mass-forming cholangiocarcinoma (sIMCC) from atypical small hepatocellular carcinoma (sHCC) (<= 3cm) in patients with cirrhosis and chronic viral hepatitis. Methods: Signal features and relative contrast of sHCCs and sIMCCs in T2-weighted and dynamic enhanced imaging were analyzed. A subgroup comparison between the cirrhosis and noncirrhosis chronic viral hepatitis group was also made. Results: Univariate analysis revealed that tumor contours (P<.001), signals in T2-weighted (P<.001) and each phase of contrast-enhanced scanning (P<.001), enhancement patterns (P<.001), as well as accompanying findings of tumor capsule (P<.001), hepatic capsule retraction (P<.001), bile duct dilation (P=.031), and transient hepatic intensity difference (P=.002) were different between sIMCC and atypical sHCC. Multivariate analysis indicated that dynamic enhancement patterns (P <.001) and signals in T2-weighted images (P=.024) were independent predictors for differentiation. Confusing MR features were more often observed in the cirrhosis group compared with those in the noncirrhosis chronic viral hepatitis group. Conclusion: Dynamic enhancement patterns and signals in T2-weighted images were the most important MR features to differentiate sIMCC from atypical sHCC with cirrhosis and chronic viral hepatitis. (C) 2014 Elsevier Inc. All rights reserved.