Value of diffusion weighted imaging signal intensity in evaluating histopathological differentiation of hepatocellular carcinoma / 中华肝胆外科杂志

ABSTRACT

Objective To determine the relationship between visual signal intensity and quantitative signal intensity of HCC assessed with DWI and histopathological differentiation of HCC.Methods The MR examinations including MRI plain scan,LAVA dynamic enhanced scan and DWI (1.5T,b value:0 and 600 s/mm2) of 224 patients who had surgically resected HCCs were retrospectively reviewed.Histopathological examinations revealed that there were 31 well-,169 moderately-,and 24 poorly-differentiated HCCs.The incidence of each visually evaluated signal intensity and quantitative signal intensity of HCC assessed with DWI signal intensity and the relationship between signal intensity and histopathological differentiation were assessed for each sequence.Results (1) On DWI,56.7％ of HCCs appeared as obviously hyperintense,24.1％ tumors appeared as moderate hyperintense,and 19.2％ tumors appeared as isotense or slight hyperintense to the surrounding hepatic parenchyma.There was a significant difference between isotense/slight hyperintense and obvious hyperintense and histopathological differentiation (P ＜ 0.05).There was no significant difference between isotense/slight hyperintense and moderate hyperintense and histopathological differentiation (P ＜ 0.05).There was no significant difference between moderate hyperintense and obvious hyperintense and histopathological differentiation (P ＞ 0.05).Visually evaluated signal Intensity of HCC showed an inverse correlation with histopathological differentiation (r =-0.324,P ＜ 0.05).On DWI,the tumors tended to show a brighter signal with decreasing histopathological differentiation.(2) There was a significant difference in DWI signal intensity value among the well,moderately and poorly differentiated HCCs (P ＜ 0.05).The SI value of well differentiated HCCs was lower than that of moderately differentiated HCCs and poorly differentiated HCCs (P ＜ 0.05).The SI value of moderately differentiated HCCs was lower than that of poorly differentiated HCCs.However,there was no significant difference between the SI value of the moderately and poorly differentiated HCCs (P ＞ 0.05).ROC analysis showed that the optimal cutoff point of SI value in diagnosing well differentiated HCCs was 66.5.A cutoff SI value equal to or less than 66.5 was used to differentiate well-differentiated HCC from moderately-and poorly-differentiated HCC with a sensitivity of 90.1％ and a specificity of 71.9％.Conclusions On DWI,the tumors tended to show a brighter,visually evaluated signal intensity and higher quantitative signal intensity with decreasing histopathological differentiation (P ＜ 0.05).The quantitative signal intensity of HCC assessed with DWI signal intensity could only predict well differentiated HCC.It was limited in predicting histopathological differentiation of HCC using evaluating signal intensity and quantitative signal intensity of HCC assessed with DWI.