MRI定量动态对比增强鉴别肝脏良恶性病变的研究

Quantitative dynamic contrast enhanced MRI in differential diagnosis of benign and malignant liver lesions

目的研究MRI动态对比增强定量参数对肝脏良恶性病变的的诊断价值。方法采用MRI扫描仪,对42例肝脏占位患者进行动态增强扫描,分别测量定量血流动力学参数:容量转移常数(Ktrans)、血管外细胞外间隙容积比(Ve)、速率常数(Kep)和血管空间容积分数(Vp),血管瘤组和肝癌组定量参数行独立样本t检验;对血管瘤组与肝癌组间绘制受试者特性曲线(ROC)曲线。结果血管瘤与肝癌Ktrans及Kep值差异均有统计学意义(P<0.05),而Ve、Vp差异无统计学意义(P>0.05)。血管瘤与肝癌Ktrans、Ve、Kep、Vp的ROC曲线下面积分别为0.907、0.661、0.966、0.582,以最大约登指数得到的最佳诊断切点值,则定量参数判断及鉴别血管瘤和肝癌的敏感度分别为85.0%、80.0%、95.0%、65.0%,特异度分别为86.3%、59.1%、81.8%、54.5%。结论 MRI定量动态对比增强血流动力学参数Ktrans、Kep对肝脏良恶性病变具有很高的鉴别诊断价值。

Objective To evaluate the value of quantitative dynamic contrast enhanced MRI in the diagnosis of benign and malignant liver lesions. Methods 42 patients of liver tumors underwent MRI examination. MR scanner was used to obtain the quantitative MR pharmaeokinetic parameters. K^trans （volume transfer constant）, Kep （exchange rate constant） and Ve （extravascular extracellular volume fraction）, Vp （volume fraction of plasma space）. The mean K^trans , Kep, Ve of malignant （liver cancer） and enign （liver hemangioma） were compared with independent sample t test. receiver operating characteristic curve hemangioma） were compared with independent sample t test. receiver operating characteristic curve （ROC） analysis were used for comparing the differences between liver cancer and liver hemangioma.Results There was significant difference between liver cancer and liver hemangioma in K^trans, Kep （P〈0.05）. The areas under the ROC curve （AUC） of K^trans, Ve, Kep and Vp between liver cancer and liver he-mangioma were 0.907, 0.661, 0.966 and 0.582, respectivly. The sensitivity of K^trans, Ve, Kep and Vp was85.0%, 80.0%, 95.0%, 65.0% and the specificity of K^trans, Ve, and Kep was 86.3%, 59.1%, 81.8%,54.5% for the differential diagnosis of liver lesions with the maximum Youden＇s index as cut off. Conclu-sion The differential diagnosis of benign and malignant liver lesions by K^trans, Kep derived from DCE-MRI is valuable.