Imaging characteristics of hypervascular focal nodular hyperplasia-like lesions in chronic alcoholic liver disease

Purpose We evaluated diagnostically differential radiological findings between focal nodular hyperplasia (FNH)-like lesions and hepatocellular carcinoma (HCC). Materials and Methods We studied pathologically confirmed FNH-like lesions in 13 alcoholic-cirrhosis patients who were negative for hepatitis-B surface antigen and hepatitis-C virus antibody and underwent dynamic computed tomography (CT) and magnetic resonance imaging (MRI), including superparamagnetic iron oxide (SPIO) and/or gadoxetic acid-enhanced MRI. Seven patients underwent angiography-assisted CT. Evaluated lesion features included arterial enhancement pattern, washout appearance (low density compared to surrounding liver parenchyma), signal intensity on T1-weighted image (T1WI) and T2-weighted image (T2WI), central scar presence, chemical shift on in- and out-of-phase images, and uptake pattern on gadoxetic acid-enhanced MRI hepatobiliary phase and on SPIO-enhanced MRI. Results Eleven patients had multiple small lesions (< 1.5 cm). Radiological features of FNH-like lesions included hypervascularity despite small lesion, lack of “corona-like” enhancement in the late phase on CT during hepatic angiography (CTHA), high-intensity on T1WI, slightly high- or iso-intensity on T2WI, no signal decrease in out-of-phase images, and complete SPIO uptake or incomplete/partial uptake of gadoxetic acid. Pathologically, like HCC, FNH-like lesions showed many unpaired arteries and sinusoidal capillarization, similar to those in HCC. Conclusion FNH-like lesions have unique radiological findings useful for differential diagnosis. Specifically, SPIO- and/or gadoxetic acid-enhanced MRI and CTHA features might facilitate differential diagnosis of FNH-like lesions and HCC.