目的 探讨动态增强磁共振成 像(dynamic contrast-enhanced MRI， DCE-MRI)定量参数对乳腺良恶性肿瘤的 鉴别能力。方法 搜集经手术病理证实 的乳腺肿瘤患者38例，其中良性肿瘤14 例，恶性肿瘤24例，术前均行DCE-MRI扫 描，选取感兴趣区测量肿瘤的DCE-MRI定 量参数Ktrans(容量转移常数)、Kep(速率 常数)、Ve(血管外细胞外间隙容积比)。 采用独立样本t检验比较良、恶性肿瘤组 间定量参数的差异，绘制ROC曲线分析 定量参数对乳腺良、恶性肿瘤的诊断效 能。结果 乳腺良性肿瘤组Ktrans、Kep、 Ve平均值分别为(0.134±0.121)min-1、 (0.273±0.137)min-1、(0.633±0.096)； 乳腺恶性肿瘤组Ktrans、Kep、Ve平均值分别 为(0.339±0.128)min-1、(0.515±0.169) min-1、(0.680±0.116)。Ktrans、Kep在 良、恶性肿瘤组间差异均有统计学意义(P ＜0.001)。Ve在良、恶性肿瘤组间差异无 统计学意义(P＞0.05)。以最大约登指数 确定最佳诊断界值，Ktrans、Kep的敏感性、 特异性和ROC曲线下面积分别为89.17%、 93.83%；94.56%、85.71%和0.929、 0.902。结论 定量参数Ktrans、Kep可作为乳 腺良、恶性肿瘤鉴别诊断的参考指标，且 有较高的诊断效能。

Objective To explore the differential diagnosis value of dynamic contrastenhanced MRI (DCE-MRI) quantitative parameters of benign and malignant breast tumors. Methods 14 cases with benign breast tumors, 24 cases with malignant breast tumors confirmed by operation, underwent the examination of DCE-MRI. ROI were drawn to record the quantitative parameters average values of Ktrans, Kep, Ve. The quantitative parameters between benign and malignant breast tumors were compared by independent samples t-test. The areas under the ROC curve of the quantitative parameters between benign and malignant breast tumors were compared. Results The average values of Ktrans, Kep, Ve in benign breast tumors were (0.134±0.121) min-1, (0.273±0.137) min-1, (0.633±0.096). The average values of Ktrans, Kep, Ve in malignant breast tumors were (0.339±0.128) min-1, (0.515±0.169) min-1, (0.680±0.116). The difference of Ktrans, Kep between benign and malignant tumors were statistically significant (P ＜0.001). The difference of Ve between benign and malignant tumors was not statistically significant (P=0.213). Using the maximum Youden index as the cut-off value, the sensitivity of Ktrans, Kep were 89.17%, 93.83%. The specificity of Ktrans, Kep were 94.56%, 85.71%. The area under the ROC curve of Ktrans, Kep were 0.929, 0.902. Conclusion The differential diagnosis of benign and malignant breast tumors by quantitative parameters Ktrans, Kep were applicable.