摘要目的 探讨体素内不相干运动(IVIM)DWI对慢性乙型肝炎炎症活动度的诊断价值.方法 前瞻性收集慢性乙型病毒性肝炎患者175例作为炎症组,收集无肝炎病史、肝功能正常的健康志愿者15名作为对照组.所有受试者均行肝脏平扫和IVIM检查.测量肝脏ADC、真性水分子扩散系数(D)、微循环灌注系数(D*)和灌注分数(f)值.炎症组在MRI检查后2 d内行B超引导下肝组织穿刺活检,获得病理肝炎活动度分级结果,并根据炎症活动度将炎症组分为G1、G2、G3+G4组.炎症组与对照组间各参数的比较采用独立样本t检验,炎症组不同肝炎活动度分级患者间的参数比较采用单因素方差分析,采用Spearman相关性分析评价炎症组炎症活动度病理分级与IVIM参数的相关性,采用ROC曲线评估IVIM参数对肝炎活动度病理分级的诊断效能.结果 炎症组和对照组的ADC、D、D*和f值的差异均有统计学意义(P<0.05).病理穿刺结果显示,G1级61例、G2级62例、G3+G4级52例.G1、G2、G3+G4级组患者间的ADC、D*和f值随炎症活动度级别的增高而逐渐降低,差异有统计学意义(P<0.05);D值差异无统计学意义(P>0.05).ADC、D*和f值与炎症活动度分级分别呈低度、中度、低度负相关,r值分别为-0.377、-0.434、-0.226,P均<0.05;D值与炎症活动度分级无相关性(r=-0.076,P>0.05).ADC值、D*及ADC联合D*值诊断≥G2级肝炎的ROC下面积分别为0.732、0.748、0.837,f值诊断≥G3+G4级肝炎的ROC下面积为0.600.结论 ADC、D*值有助于鉴别≥G2级肝炎, ADC联合D*值的诊断效能最高.

abstractsObjective To discuss the diagnostic value of intravoxel incoherent motion(IVIM)DWI in the inflammation activity of chronic hepatitis B. Methods One hundred and seventy-five patients with chronic hepatitis B were prospectively collected as inflammation group, and 15 healthy volunteers with no history of hepatitis and normal liver function as control group.All subjects were performed MR plan scans for liver and IVIM tests.The liver apparent diffusion coefficient(ADC),the diffusion coefficient of the true water molecule (D), microcirculation perfusion coefficient (D*) and perfusion fraction (f) were measured. After MRI examination, the inflammation group received liver biopsy within two days, and obtained the pathological hepatitis activity grades.According to the degree of inflammation activity(G),the inflammation group was divided into G1,G2 and G3+G4 groups.The independent sample t test was used for the parameter values between the inflammation group and the control group.A single factor variance analysis was used to compare the parameters among different levels of inflammation group. Spearman correlation analysis was used to evaluate the correlation between inflammation activity grades and IVIM parameters.ROC curve was used to evaluate each parameter in the diagnosis of hepatitis activity pathology classification efficiency.Results The values of ADC, D, D*, f between control group and inflammation group were statistically significant(P<0.05).The results of pathological puncture showed that there were 61 cases of G1,62 cases of G2 level and 52 cases of G3+G4.The ADC,D*and f values in the G1,G2,G3+G4 groups decreased with the increase of the level of inflammation activity, and the difference was statistically significant (P<0.05). There was no statistically significant difference between D values (P>0.05). ADC, D* and f values were correlated negatively with low,moderate and low levels of inflammation activity(r=-0.377,-0.434,-0.226, P<0.05).There was no correlation between D value and inflammation activity(r=-0.076,P>0.05).Areas of ADC,D*and ADC combined with D*values under ROC curves to diagnose≥G2 grade inflammation activity were 0.732, 0.748, 0.837 respectively. Areas of f values under ROC curve to diagnose ≥G3+G4 grade inflammation activity was 0.600.Conclusion ADC and D*values help to identify≥G2 grade inflammation activity,and ADC combined with D*value has the highest diagnostic performance,and has certain reference value for clinical treatment.