MR扩散加权成像对肝纤维化诊断的初探

目的探讨MR扩散加权成像对肝纤维化的诊断价值，同时与反映肝纤维化的血液生化学指标作对比分析。方法分别对41例经肝穿确诊的肝纤维化病人及10例正常对照组利用扩散成像技术测定b值为600S／mm^2时的表观扩散系数（ADC），同时测量血液生化学指标，包括透明质酸（HA）以及肝纤维化诊断预测模型Forns和APRI指数。结果（1）随肝纤维化程度进展，ADC值依次减低，差异有显著统计学意义（P〈0．01）；组间比较，ADC值除在S0与S1期间无差异外，余各期间差异均有统计学意义（P〈0．05）；ADC值与肝纤维化分期之间具有很好的负相关性。（2）ADC值、血液生化学指标的ROC曲线下面积（AUG）均〉0．7。在判断s≥2为阳性标准时，ADC值的AUC为0．88、敏感性为75．9％、特异性为83．3％；在判断S≥3为阳性标准时，ADC值的AUG为0．93、敏感性为86.7％、特异性为88．5％。无论在判断S≥2或者是S≥3为阳性标准的情况下，ADC值的AUC均大于血液生化学指标。结论MR扩散加权成像ADC值是一种能有效检测中重度肝纤维化和早期肝硬化的影像学诊断方法。

Diagnosis of hepatic fibrosis with MR diffusion weighted imaging: preliminary results

Objective To choose a noninvasive method for assessing hepatic fibrosis reasonablely in our clinical study, and compared with histopatbology, the changes of ADC value and blood biochemiology in patients were analyzed. Methods 41 patients of hepatic fibrosis who received liver biopsy and 10 healthy volunteers were included in this study. All of them underwent DWI on 1.5T MRI device. Apparent diffusion coefficient （ADC） of liver were measured when b value were set as 600s/mm^2. Blood samples were obtained in all patients to observe blood biochemiology of hepatic fibrosis including hyaluronic acid（HA）, and Forns index, APRI index. Statistical analysis was performed by SPSS 16.0 for windows statistical software, P 〈 0.05 was considered statistically significance. Results 1.ADC values decreased gradually as the stage of fibrosis progressed（P 〈 0.01）. When b value was 600s/mm^2, ADC values have statistically significance（P 〈 0.05） except only between S0 and S1. There was a good negative correlation between ADC values and stages of fibrosis. 2. The ADC values and the blood biochemiology indices were all of certain value in diagnosis hepatic fibrosis with the AUC 〉 0.7. In discriminating patients staged S ≥ 2, the areas under the receiver operating characteristic curves（AUC） were 0.88 for ADC, the sensitivity, the specificity were 75.9%, 83.3%, respectively; In discriminating patients staged S ≥ 3, the areas under the receiver operating characteristic curves（AUC） were 0.93 for ADC, the sensitivity, the specificity were 86.7%, 88.5%, respectively. Not only when S ≥ 2 but also S ≥ 3 for one with hepatic fibrosis was arbitrarily defined, the AUC of ADC values were larger than blood biochemiology indices. Conclusion DWI was an effective method to quantify severity hepatic fibrosis as well as to detect moderate-severe fibrosis and early cirrhosis.