Clinical application of conventional magnetic resonance imaging and diffusion-weighted imaging in differentiating histopathological types of small hepatocellular carcinoma / 中华肝胆外科杂志

ABSTRACT

Objective To study the imaging apperances and the diagnostic value of conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in differentiating histopathological types of small hepatocellular carcinoma (sHCC).Methods 40 sHCC confirmed by histopathology were classified into 4 groups according to their degree of differentiationwell (n=6),well-moderate (n=5),moderate (n=27) and moderate-poor (n =2).All patients received conventional MRI and DWI (1.5T,b =0 and 600 s/mm2) before the operation.The ADC values of the sHCC were measured and compared.Results On T1WI,32 lesions showed hypointensity,4 hyperintensity (well) and 4 isointensity (well-moderate =2,moderate =2).On T2WI,hyperintensity was observed in 39 lesions and isointensity in 1 lesion (well).Steatosis in the sHCC was seen in 17 of 40lesions (17/40,42.5 ％,well=4,well-moderate=1 and moderate=12).A pseudocapsule was seen in 67.5 ％ sHCC (27/40,well=4,well-moderate=3,moderate=18 and moderate-poor=2).32 lesions showed hypervascularity on arterial phase,and 8 lesions showed hypovascularity (well=3,moderate =4,moderate-poor=1).On DWI,37 lesions showed hyperintensity,except for 3 lesions with welldifferentiated sHCC which showed isointensity (50％,3/6).The mean ADC values±S.D.of sHCC in the well,well-moderate,moderate and moderate-poor groups were (1.757 ± 0.337) × 10-3,(1.917±0.574)×103,(1.816±0.545)×103 and (1.723±0.217)×10-3,respectively.There were no significant differences among the 4 groups.Conclusion The imaging appearances of wellmoderate,moderate and moderate-poor sHCC on conventional MRI were classical which make diagnosis easy.Hyperintensity on DWI contributed to diagnosis.However,the imaging appearances of some well-differentiated sHCC were atypical.The lesions could be isointensity or hyperintensity on DWI.The combination of conventional MRI and DWI contributed to better diagnosis of sHCC,especial for atypical sHCC.