半定量双回波动态对比增强MRI诊断乳腺肿瘤的价值

Semi-quantitative dynamic contrast enhanced MRI in diagnosing of breast tumor

目的探讨双回波动态对比增强MRI半定量参数对乳腺肿瘤的诊断价值。方法回顾性分析采用3．0TMR扫描仪和16通道乳腺相控阵线圈行双回波动态对比增强MRI检查38例乳腺肿瘤患者资料，患者均经手术或穿刺病理证实诊断。测量半定量血流动力学和灌注参数，包括峰值强化率（PER）、达峰时间（Tmax）和最大信号损失率（MSIL）。采用单因素方差分析比较乳腺癌、纤维瘤和其他良性病变的差异，ROC曲线分析半定量参数诊断良恶性病变的敏感度、特异度和准确度。结果乳腺癌（20例）患者的PER、Tmax和MSIL分别为0．61±0．09、（164．9±20．5）S和0．31±0．03；纤维瘤（10例）的上述均值分别为0．46±0．07、（183．2±13．7）s和0．17±0．03；其他良性病变（8例）患者的上述均值分别为0．23±0．06、（139．4±23．6）S和0．24±0．07，3组患者间PER、Tmax和MSIL的差异均有统计学意义（F值分别为4．319、4．154和4．752，P值均〈0．05）。PER、Tmax和MSIL三者ROC曲线下面积分别是0．513、0．794、0．769，以最大约登指数为最佳诊断切点值，PER、Tmax和MSIL判断乳腺良恶性病变的敏感度分别为60．O％、80．0％和62．5％；特异度分别为62．5％、75．0％和90．0％。综合3个半定量参数作为联合指标诊断良恶性病变的敏感度、特异度和准确度分别为95．0％（19／20）、83．3％（15／18）和89．4％（34／38）。结论双回波动态对比增强MRI能同时测量半定量血流动力学参数PER、Tmax和灌注参数MSIL，3个半定量参数作为联合指标可提高乳腺良恶性病变的诊断正确性。

Objective To evaluate the semi-quantitative parameters of dynamic contrast enhanced MRI （DCE MRI） with double echo in the diagnosis of breast tumors. Methods Thirty eight patients suspected of breast tumour underwent DCE MRI with double echo examination by using 3.0 T whole-body MR scanner with a sixteen-channel phased-array breast coil. Semi-quantitation of both pharmacokinetic and perfusion parameters were performed including peak enhancement ratio （ PER ） , time from contrast agent arrive to peak enhancement （Tmax） , and maximum signal intensity loss （MSIL）. The mean PER, Tmax and MSIL of the breast cancer, fibroma and other benign lesions were calculated. One-way ANOVA and receiver operating characteristic curve （ROC） analysis were used to compare the differences between malignant and benign lesions. Results The mean PER, Tmax and MSIL of the lesions were as follows ： 0. 61 ±0. 09, （164. 9 ± 20. 5 ） s, and 0.31 ±0.03 for breast cancers （n =20）; 0.46 ±0.07,（183.2 ± 13.7）s,and 0. 17 ±0. 03 for fibromas （ n = 10） ; 0. 23 ± 0. 06, （ 139.4 ± 23.6 ） s, and 0. 24 ± 0. 07 other benign lesions （ n = 8 ） , respectively. There were significant differences among 3 groups in all semi-quantitative parameters （ F = 4. 319,4. 154,4. 752, respectively. P 〈 0. 05 ）. The areas under the ROC curve of PER, Tmax and MSIL for the diagnosis of malignant lesions were 0. 513,0. 794 and 0. 769, respectively. The sensitivity of PER, Tmax,and MSIL were 60. 0% ,80. 0% and 62. 5% and the specificity were,62. 5% ,75.0% and 90. 0% ,