肝纤维化磁共振扩散相关成像与病理学结果关系的对照研究

Initial study on correlation between MR diffusion imaging and pathological results in patients with liver fibrosis

目的 :探讨磁共振体素内不相干运动(intravoxel incoherent motion,IVIM)及扩散峰度成像(diffusional kurtosis imaging,DKI)在轻中度肝纤维化诊断中的价值。方法 :23例弥漫性肝病患者行磁共振IVIM、DKI检查及CT引导下肝脏穿刺活检术。在磁共振图像上测得定量DKI相关指标和标准表观弥散系数(apparent diffusion coefficient,ADC)、快速ADC、慢速ADC、快速ADC/总ADC比例。以病理组织学诊断为金标准,统计分析各磁共振指标与肝纤维化分期、Knodell组织学活动指数(炎症评分)间的相关性,评估其诊断价值。结果:随着肝纤维化分期进展,MD、Dr、标准ADC、慢速ADC值均有逐渐下降的趋势,但差异尚无统计学意义。随着炎症评分程度加重,Dr值呈下降趋势,MK、Kr值呈上升趋势,但差异亦无统计学意义。MD、Dr值、快速ADC值与肝纤维化分期之间具有中度负相关性。快速ADC值与肝纤维化炎症评分之间具有中度负相关性。结论 :磁共DKI及IVIM在轻中度肝纤维化诊断中具有一定价值,其中DKI中MD、Dr指标和IVIM中快速ADC值有助于肝纤维化分期诊断。

Objective： To investigate the value of MR intravoxel incoherent motion（IVIM） and diffusional kurtosis imaging（DKI）in the diagnosis of mild and moderate liver fibrosis. Methods： Twenty-three patients with diffuse lesions of liver undergone MR DKI,IVIM and CT-guided liver biopsy were enrolled.DKI-related indices（FA, MD, Da, Dr, MK, Ka,Kr values） and standard ADC, fast ADC, slow ADC, fraction ADC were calculated. Pathological diagnosis was taken as the golden standard,correlations of MR parameters with staging of liver fibrosis and Knodell HAI score were statistically analyzed, and value of MR in diagnosing liver fibrosis was evaluated. Results： With the progression of liver fibrosis, MR, MD,Dr, standard ADC, slow ADC values gradually decreased,but without statistical significance（P〉0.05）. With the increase of Knodell HAI score, Dr values decreased and MK, Kr values increased but with no statistical significance. There was mode rate negative correlation between MD, Drvalue, fast ADC value and hepatic fibrosis stage,and moderate negative correlation between fast ADC value and inflammation score. Conclusions： MR, DKI and IVIM imaging are helpful for evaluating mild and moderate liver fibrosis,and DKI MD, Dr and IVIM fast ADC values could be used for staging of liver fibrosis.