Small hepatocellular carcinoma with peripheral enhancement:pathological correlation with dual phase images by helical CT

<正> Background The peripheral enhancement of small hepatocellular carcinoma(SHCC)is a rare appearance in dualphase images by helical computed tomography(CT).This study discusses this phenomenon and its correlativehistopathology.Methods The helical CT dual phase appearance of peripheral enhancement in SHCC was analyzed in 21 cases(22lesions).All lesions were confirmed as SHCC by histopathological examination.Results In these 22 lesions,enhanced peripheral ring in 20 lesions was incomplete,the thickness of enhancedperipheral ring varied and mural node could be found in hepatic arterial phase;only 2 lesions had complete peripheralring enhancement and ring of uniform thickness in hepatic arterial phase.The enhancement of some peripheral ringsand mural nodes dropped to very low density in portal venous phase.The tumour cells were grade Ⅰ in 3 lesions,Ⅱ in16,Ⅲ in 2 and Ⅳ in 1.The vascular supply was more abundant at the border than in the centre of 15 lesions and thevascular supply was deficient in both centre and border of the remaining 7 lesions.In 3 lesions,the pseudocapsuleshowed in the border of the lesion.In 12 lesions,flecks of necrosis were found in the border and/or centre of thelesion.Conclusions The characteristic peripheral enhancement in helical CT dual phase images of small hepatocellularcarcinoma correlates with different vascular supplies,fibrous capsule and necrosis of the lesion.