3.0T MR表观弥散系数对慢性乙型肝炎肝纤维化程度的评估

Evaluation of the degree of liver fibrosis in patients with chronic hepatitis B using 3.0 T magnetic resonance ADC value

目的:探讨3.0T MR测定表观弥散系数(apparent diffusion coefficient,ADC)值评估慢性乙型病毒性肝炎(chronic hepatitis B,CHB)所致肝脏纤维化(liver fibrosis,LF)程度的价值.方法:选取经肝脏穿刺活检确诊的CHB肝纤维化患者47例(其中S1期10例,S2期10例,S3期14例,S4期13例),经临床及影像学确诊的肝硬化患者(S5)14例及健康正常人(S0)10例,进行3.0T MR弥散加权成像(diffusion weighted imaging,DWI)检查;测量肝脏ADC值并计算其平均值.分析各组间ADC值的差异及其与LF程度、炎症程度的相关性;采用受试者工作特征曲线(ROC曲线)分析ADC值评估LF程度的能力.结果:LF程度与ADC值呈负性相关(R^2=0.859,P=0.000),组间ADC值均有统计学差异(F=40.868,P<0.001),组内相互比较:S0与S2、S3、S4、S5之间,S1与S2、S3、S4、S5之间,S2与S0、S1、S3、S4、S5之间,S3与S0、S1、S2、S5之间,S4与S0、S1、S2之间,S5与S0、S1、S2、S3之间,组间具有统计学差异(P<0.05).S0、S1+S2(轻度LF)、S3+S4(重度LF)、S5组间差异有统计学意义(F=49.215,P<0.001),组内两两比较,均有统计学差异(P均<0.05).ROC曲线显示ADC值预测LF(S≥1,S≥3,S=5)有统计学意义(P=0.000);以ADC≤1.229诊断S≥1的敏感性为91.7%、特异性为88.5%,以ADC≤1.109诊断S≥3的敏感性为96.9%、特异性为90.2%,以ADC≤1.034诊断S=5的敏感性为81.4%、特异性为85.7%.结论:无创、简便的DWI检查测量肝脏ADC值,可为临床评估CHB肝纤维化的程度提供重要依据.

Objective:To investigate the application value of 3.0 magnetic resonance(MR)apparent diffusion coefficient(ADC)for evaluating liver fibrosis(LF)induced by chronic hepatitis B(CHB).Methods:Diffusion weighed imaging(DWI)was performed in 47 patients with liver fibrosis(S1 10 cases,S2 10 cases,S3 14 cases,S4 13 cases)under biopsy,14 with cirrhosis(S5)diagnosed by clinical and imaging examination and 10 healthy volunteers(S0).The ADC value of liver in each subject was measured and the mean value was calculated.The diversification of ADC value between groups,and the correlation between ADC value and stage of LF,grade of inflammation was analyzed.Receiver operation characteristics(ROC)analysis was used to assess the performance of ADC value in predicting stage of LF.Results:There was significant negative correlation between ADC value and fibrosis stage(R 2=0.859,P=0.000).The ADC value showed significant statistical difference among groups(F=40.868,P<0.001).When compared between any two groups,except S0 and S1 group,S3 and S4 group and S4 and S5 group,the ADC value was significantly different between any other two groups(P<0.05).When the groups were divided into healthy control(S0)group,mild stage of fibrosis(S1+S2)group,severe stage of fibrosis(S3+S4)group and cirrhosis(S5)group,significant difference was also observed among groups(F=49.215,P<0.001),and between any two groups(P<0.05).ROC analysis indicated that hepatic ADC value was a significant predictor of liver fibrosis of stage 1 or greater(S≥1)and stage 3 or greater(S≥3),and cirrhosis(S5)(P=0.000),with areas under the curve of 0.914,0.981 and 0.884,respectively.As for prediction of fibrosis of S≥1,S≥3 and S5 with ADC value≤1,229,1.109 and 1.034,respectively,the accuracy sensitivity and specificity were 91.7%and 88.5%,96.9%and 90.2%,81.4%and 85.7%.Conclusion:Liver ADC value measured by simple noninvasive diffusion weighted MRI can provide important evidence for prediction of the degree of liver fibrosis in CHB patients in clinic.