CT of hepatocellular carcinoma in non-alcoholic fatty liver disease: imaging characteristics and interrater agreement

Aim: To determine the computed tomography (CT) features of non-alcoholic fatty liver disease (NAFLD) associated hepatocellular carcinoma (HCC). Methods: In this institutional review board approved study, we reviewed 38 patients with NAFLD (68.4% male; mean age 63 years) with histology confirmed HCC and triphasic liver CT. CT images were independently reviewed by four readers blinded to clinical and pathology data. The reviewers assessed HCC for arterial phase hyper enhancement (APHE), portal venous phase washout (PVWO), delayed phase washout (DPWO), and enhancing capsule. Features of cirrhotic morphology and portal hypertension (PH) were also evaluated. The final CT features were determined by majority and a fifth reader reviewed cases lacking majority. Inter-rater agreement was determined by prevalenceadjusted kappa. Results: Mean HCC size was 3.6 ± 2.8 cm (range, 1.1-16.0 cm). The HCCs showed APHE in 92.1%, PVWO in 55.3%, DPWO in 81.6%, and enhancing capsule in 44.7%. Cirrhotic morphology was present in 65.8% and PH in 63.2%. Inter-rater agreement was moderate to almost perfect for APHE (0.74-1.0), cirrhosis (0.79-0.89), and PH (0.790.95), weak to perfect for DPWO (0.47-0.95) and poor for PVWO (0-0.42). Conclusion: NAFLD associated HCC demonstrate less frequent portal venous washout on CT which may affect their imaging diagnosis.