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目的:探讨基于动态增强磁共振成像(dynamic contrast-enhanced MRI,DCE-MRI)及特定药物动力学模型所获得的量化参数对乳腺良恶性病变诊断价值。方法:收集我院2015年6月至2016年2月42例乳腺病变患者行DCE-MRI扫描,通过后处理软件测量如下量化参数,定量参数:容量转移常数(volume transfer constant,Ktrans)、速率常数(rate constant,Kep)、血浆分数(the plasma fraction,Vp);半定量参数:(1)增强后病灶达峰时间(time to peak,TTP)、(2)增强后病灶内造影剂最大浓度值(max concentration,MAX Conc)、(3)增强后时间信号曲线下面积(area under curve,AUC)、(4)增强后时间信号曲线最大斜率值(MAX Slope)。检查后1周内均经手术取得病理诊断,采用独立样本t检验或非参数检验比较良性组及恶性组间各量化参数的差异。绘制ROC曲线,并分析有价值量化参数对乳腺良、恶性病灶诊断价值。结果:恶性病灶组定量参数KtransMax(t=2.228,P=0.033)、Ktrans Mean(t=4.092,P<0.001)、KepMean(Z=2.422,P=0.015)、KepMax(t=2.240,P=0.031)及半定量参数MAX Conc Max(t=3.256,P=0.002)、MAX Conc Mean(t=3.460,P=0.001)、AUC Max(t=2.250,P=0.034)、AUC Mean(t=2.861,P=0.007)、MAX Slope Max(t=2.478,P=0.018)、MAX Slope Mean(t=2.226,P=0.032)较良性病灶组值明显升高,而半定量参数TTP Min(t=-5.145,P<0.001)、TTP Mean(t=-3.818,P<0.001)较良性病灶组明显缩短。经ROC曲线分析显示,KtransMean、KepMean、TTP Min、MAX Conc Max、AUC Mean、MAX Slope Max对乳腺良恶性病变具有诊断价值,根据最大约登指数计算最佳诊断阈值,分别以0.1137、0.0258、0.9065、0.1059、0.1640、0.1502为诊断阈值,其鉴别诊断乳腺病灶良恶性敏感度分别为73.33%、73.33%、91.67%、76.67%、80.00%、80.00%,特异性分别为100%、83.30%、70.00%、91.70%、66.70%、75.00%。结论:基于DCE-MRI技术及特定的药物动力学模型所获得的量化参数对乳腺良恶性病变鉴别诊断有临床价值,且有较高的诊断效能,有望成为无创性评价乳腺肿瘤微循环的新方法。
Objective: To investigate the diagnostic value of quantitative parameters obtained from dynamic contrast-enhanced MRI (DCE-MRI) and specific pharmacokinetic models for benign and malignant breast lesions. Methods: DCE-MRI scan was performed in 42 cases of breast lesions from June 2015 to February 2016 in our hospital. The following parameters were measured by post-processing software: volume transfer constant (Ktrans), rate constant (rate constant, Kep) and the plasma fraction (Vp). Semiquantitative parameters: (1) time to peak (TTP) enhancement, (2) maximum concentration of contrast medium in the lesion (max concentration, MAX Conc), (3) area under curve (AUC), and (4) MAX Slope of the enhanced time signal curve. Pathological diagnosis was obtained by surgery within 1 week after the examination. The independent samples t-test or non-parametric test were used to compare the difference of quantification parameters between benign and malignant groups. ROC curve was drawn and the diagnostic value of valuable quantitative parameters for benign and malignant breast lesions was analyzed. Results: KtransMax (t = 2.228, P = 0.033), Ktrans Mean (t = 4.092, P <0.001), KepMean ) And MAX Conc Max (t = 3.256, P = 0.002), MAX Conc Mean (t = 3.460, P = 0.001), AUC Max (P = 0.007), MAX Slope Max (t = 2.478, P = 0.018) and MAX Slope Mean (t = 2.226, P = 0.032) , P <0.001). TTP Mean (t = -3.818, P <0.001) was significantly shorter than that in benign lesions. According to the ROC curve analysis, KtransMean, KepMean, TTP Min, MAX Conc Max, AUC Mean and MAX Slope Max have diagnostic value for benign and malignant breast lesions. According to the maximum Youden index, the optimal diagnostic thresholds are calculated, respectively, and calculated as 0.1137,0.0258,0.9065 , 0.1059,0.1640,0.1502 as diagnostic threshold, the differential diagnosis of benign and malignant lesions of breast lesions were 73.33%, 73.33%, 91.67%, 76.67%, 80.00%, 80.00%, respectively, the specificity was 100%, 83.30%, 70.00 %, 91.70%, 66.70%, 75.00%. Conclusion: The quantitative parameters obtained based on DCE-MRI technique and specific pharmacokinetic model have clinical value in the differential diagnosis of benign and malignant breast lesions and have high diagnostic efficacy, which is expected to be a noninvasive new method for evaluating microcirculation of breast tumors .