The MDCT appearances of small hepatocellular carcinoma(≤20 mm in diameter)in patients with chronic hepatitis

Objective To study multiphasic MDCT enhancement pattern of small hepatocellular carcinoma(HCC)smaller than 20 mm in diameter in patients with chronic hepatitis.Methods This retrospective analysis of 39 pathologically proven small HCC smaller than 20 mm were detected at multiphasic(arterial,portal and late phases)contrast-enhanced MDCT.Images were assessed for MDCT findings including lesion size,density,enhancement patterns,and tumor capsules.Results The contrast enhancement patterns of small HCC at MDCT were divided into 5 types.① Nodular-like enhancement on arterial phase in 22 cases(56.4%);② Cloudlike enhancement on arterial phase in 9 cases(23.1%);③ Without enhancement in 6 cases(15.4%);④ Ring enhancement during the arterial and portal phases in 1 case;⑤A nodule within a nodulein 1case.The typical HCC enhancement pattern at MDCT(arterial hyperattenuation with portal and late phase washout)was identified in 51.3% for our study.Conclusion HCC smaller than 20 mm frequently have multiple enhancement patterns and require careful evaluation multiphase images to improve the accuracy in the diagnosis.