磁共振DWI对慢性乙型肝炎肝纤维化程度和活动度的评价

目的：探讨磁共振弥散加权成像（DWI）评价慢性乙型肝炎肝纤维化程度和肝炎活动度的价值。方法设置不同的弥散敏感系数b值对102例慢性乙型肝炎患者（肝炎组）和26例健康志愿者（对照组）进行磁共振DWI检查，测定并比较两组肝脏感兴趣区的表观弥散系数（ADC）值。肝炎组进一步分为纤维化组（n＝74）和无纤维化组（n＝28）。结果设置b值为100和200 s／mm2时，两组ADC值比较差异无统计学意义（P＞0．05）；b值为400、600和800 s／mm2时，肝炎组ADC值低于对照组，肝纤维化组ADC值低于无纤维化组，差异有统计学意义（P＜0．05）；b值为600及800 s／mm2时，肝纤维化组S3及S4期ADC值低于S0及S1期，差异有统计学意义（P＜0．05）；b值为100、200和400 s／mm2时，不同肝纤维化程度分期 ADC值间的差异无统计学意义（P＞0．05）；b值为800 s／mm2时，不同炎症活动度组G1与G4级的ADC值的差异有统计学意义（P＜0．01），其余组间差异无统计学意义（P＞0．05）。结论磁共振DWI技术在评价不同分期慢性乙型肝炎肝纤维化程度和活动度方面具有较好的应用价值，设置b值为800 s／mm2时，效果最佳。

Evaluation of liver fibrosis degree and activity in chronic hepatitis B by magnetic resonance diffusion weighted imaging

Objective To investigate the value of magnetic resonance(MR) diffusion weighted imaging (DWI) for evaluating the degree of liver fibrosis and hepatitis activity in the patients with chronic hepatitis B .Methods A total of 102 cases of chronic hepatitis B and 26 healthy volunteers underwent MR DWI by setting up different diffusion sensitivity coefficients(b value) ,the ap‐parent diffusion coefficient (ADC) values in the liver interest regions were determined and compared between the two groups .hepa‐titis group was further divided into fibrosis group(n= 27) and non‐fibrosis group(n= 28) .Results In the b values of 100 ,200 s/mm2 ,ADC had no statistically significant differences between the two groups (P>0 .05) .In the b values of 400 ,600 ,800 s/mm2 , the ADC value in the hepatitis group was significantly lower than that in the control group ,which in the hepatic fibrosis group was significantly lower than that in the non‐fibrosis group ,the differences were statistically significant (P<0 .05);in the b values of 600 ,800 s/mm2 ,the ADC values of the stage S3 and S4 in the hepatic fibrosis groups was significantly lower than those of the stage S0 and S1 ,the difference was statistically significant (P<0 .05);in the b values of 100 ,200 ,400 s/mm2 ,the ADC values of different stages of liver fibrosis had no statistically significant difference (P>0 .05);in the b value of 800 s/mm2 ,the ADC values of the grade G1 and G4 had statistically significant differences among different inflammatory activity groups (P<0 .01) ,the rests had no statistical difference between groups (P>0 .05) .Conclusion MR DWI technique has the better application value in the aspect of the evaluation of liver fibrosis degree and activity in the patients with chronic hepatitis B ,by setting up the b value =800 s/mm2 , the effect is best .