MR容量转移常数（Ktrans）对乳腺肿瘤的诊断价值研究

目的 探讨1.5 T动态增强磁共振成像（DCE-MRI）容量转移常数（Ktrans）对乳腺良恶性肿瘤的诊断价值.方法 采用1.5 T MRI扫描成像仪和8通道乳腺相控阵线圈对乳腺肿块性质待定的患者进行DCE-MRI检查.多病灶患者取最大者纳入研究,最终收集26个病灶,其病理结果为乳腺癌16例、乳腺纤维腺瘤10例.测量并记录两组病灶的Ktrans（mean）、Ktrans（max）、表观扩散系数（ADC）.采用Levene方差分析比较两组间差异,受试者特性曲线（ROC）描述并比较Ktrans与ADC两者的诊断效能.结果 乳腺癌的Ktrans（mean）为（0.56±0.12）min-1、Ktrans（max）为（2.25±0.43）min-1、ADC值为（1.36±0.27）×10-3mm2/s;乳腺纤维腺瘤的Ktrans（mean）为（0.17±0.03）min-1、Ktrans（max）为（0.37±0.07）min-1,ADC值（1.36±0.20）×10-3mm2/s.乳腺癌与乳腺纤维腺瘤间Ktrans差异有统计学意义.以最大约登指数作为最佳诊断切点值,即Ktrans（mean）=0.26min-1、Ktrans（max）=0.58min-1、ADC=1.38×10-3mm2/s作为阈值时,三者判断乳腺良恶性病变的敏感度分别为87.5％、93.8％和62.5％;特异度分别为80.0％、90.0％和60.0％;曲线下面积分别为0.900、0.944、0.528.结论 Ktrans对乳腺肿瘤良、恶性鉴别诊断具有显著临床价值,且诊断效能明显优于ADC.

Objective To evaluate the value of volume ^mansfer constant （ Ktrans） of 1.5 T dynamic enhanced magnetic resonance imaging （ DCEMRI ） in the differential diagnosis of benign and malignant breast tumors. Methods 26 patients suspected of breast tumour were collected and underwent DCE-MP, I examination using 1.5 T whole-body MR. scanner with a 8-channel phased-array breast coil. In the patients with multiple lesions, the max lesions were enrolled in the study. The pathological results were as follows： 16 cases were breast cancer and 10 cases were breast fibroma. The K^trans （ mean ） , K （ max ） and the apparent diffusion coefficient （ ADC ） of the two groups were measured and recorded. Levene variance analysis and two independent samples of t-test were used to compare the differences between the two groups. The receiver operating characteristic curve （ ROC ） analysis was used for comparing the diagnostic effectiveness between Ktrans and ADC. Results The K （ mean ） , K （ max ） and ADC of breast cancer as follows： 0.56±0.12rain-j, 2.25±0.43min^-1 and （ 1.3±0.27）×10^-3mm^2/s. The K （ mean ） , K （ max ） and ADC of breast fibroma were 0.17±0.03min^-1, 0.37±0.07min^-1 and （ 1.36±0.20 ）×10^-3mm^2/s. There were significant differences between breast cancer and breast fibroma in K （ mean ） and K^trans（ max ） （ P=0.001, 0.000 ） . The sensitivity of K （ mean ） , K （ max ） and ADC were 87.5%, 93.8% and 62.5% and the specificity of those were 80.0%, 90.0% and 60.0%, respectively, for differential diagnosis of breast lesions with the maximum Youden＇ index as cue off. And those area under the curve were 0.900, 0.944, 0.528. Conclusion K^trans is applicable in the differential diagnosis of benign and malignant breast lesions and the diagnostic efficiency is obviously better than that of ADC.