MR扩散加权联合动态增强评估乙型病毒性肝炎肝纤维化分级的研究

Study of combined DWI with dynamic contrast-enhanced MRI in staging of hepatic fibrosis in patients with chronic hepatitis B

目的探讨肝ADC值联合肝动脉灌注指数(HPI)诊断慢性乙型病毒性肝炎(CHB)肝纤维化分级的价值。方法前瞻性收集乙型肝炎病毒感染时间≥1年且准备行肝脏穿刺活检的69例CHB患者作为病例组,肝功能正常的健康体检者15例作为对照组。所有受试者均行上腹部DWI和动态增强(DCE)检查,分别测得肝ADC值和动脉灌注指数(HPI)值。病例组受试者行肝穿刺,并按照纤维化程度分为S0~S4级。采用单因素方差比较不同纤维化程度分级患者间肝脏ADC值、HPI值的差异,采用Spearman等级相关检验分析病例组肝脏纤维化程度与肝脏ADC值、HPI值的相关性,并采用ROC曲线分析肝脏ADC值和HPI值诊断肝纤维化的效能。结果病例组S0、S1、S2、S3及S4级分别有11、13、12、15及18例。对照组、S0级组、S1级组、S2级组、S3级组、S4级组患者的ADC值分别为(1.39±0.09)×10^(-3)、(1.39±0.08)×10^(-3)、(1.38±0.10)×10^(-3)、(1.20±0.06)×10^(-3)、(1.12±0.07)×10^(-3)、(1.01±0.07)×10^(-3)mm^2/s;HPI值分别为(0.23±0.04)、(0.23±0.03)、(0.26±0.03)、(0.29±0.03)、(0.36±0.07)、(0.41±0.05),各组间差异均有统计学意义(P均<0.01)。病例组肝ADC值与肝脏纤维化程度呈高度负相关(r=-0.894,P<0.01),HPI值与肝脏纤维化程度呈高度正相关(r=0.832,P<0.01)。ADC值预测≥S1级、≥S2级、≥S3级、S4级肝纤维化的ROC下面积分别为0.893、0.991、0.966、0.952,HPI值预测上述分级肝纤维化的ROC下面积分别为0.924、0.928、0.943、0.905。结论肝ADC值较HPI值对肝纤维化程度区分有更高的诊断价值,二者联合应用可提升诊断效能。

Objective To assess the value of combined liver ADC and hepatic perfusion index （HPI） values in staging hepat- ic fibrosis in patients with chronic viral hepatitis B （CHB）. Methods Fifteen healthy volunteers （ control group） and 69 patients with CHB （disease duration more than 1 year） （patient group） were prospectively recruited. All of the subjects underwent DWI and dynamic contrast-enhanced （DCE） experiments. Liver ADC and hepatic perfusion index （HPI） values were obtained for sub- sequent analysis. Sixty nine patients who had biopsy were grouped according to their pathological grading of fibrosis, from SO to $4. One way ANOVA was used to compare the ADC and HPI values between the five different fibrosis groups and control group. Spearman correlation analysis was used to analyze the correlations between the ADC and HPI values and those staging factors. Finally, receiver operating characteristic （ROC） curve analysis was performed to compare the diagnostic performance of ADC and HPI values in discriminating different stages of hepatic fibrosis. Results Based on the pathological results, the 69 patients were reclassified to five subgroups with 11, 13, 12, 15 and 18 patients in the SO, S1, S2, S3, and S4 groups respectively. ADC values were （1.39±0.09） ×10^-3, （1.39±0.08） ×10^-3, （1.38±0.10） x 10.3, （1.20±0.06）×10^-3, （1.12±0.07）×10^-3 and （1.01 ±0.07）×10^-3mm^2/s for the control group and stages SO to S4, respectively. HPI values were （0.23 ±0.04）, （ 0. 23± 0. 03 ）, （0.26 ± 0.03 ）, （0.29 ± 0.03 ）, （0.36± 0.07 ） and （0.41± 0.05 ） for stages SO to S4 and the control group, respectively. Statistically significant differences were observed among them （ P 〈 0.01 ）. Both ADC （ r = -0. 894, P 〈 0.01 ） and HPI （ r = 0. 832, P 〈 0.01 ） values were highly correlated with the stages of liver fibrosis. The area under ROC （AUC） for predicting fibrosis stages （ ≥S1, ≥S2, ≥S3 and S4） with ADC values was O. 893, 0. 991,0. 966 and 0. 952, respectively. Accordingly, the AUC for HPI values were 0. 924, 0. 928, 0. 943 and 0.905. Conclusion Compared with HPI, liver ADC values may have better diagnostic performance in differentiating degrees of hepatic fibrosis. Multi-modal diagnosis could increase diagnostic efficacy.