MRI扩散加权成像对乳腺良恶性病变的诊断

目的:探讨磁共振扩散加权成像(DWI)对乳腺良恶性疾病的诊断价值。方法:回顾性分析40例经病理确诊的乳腺疾病,其中良性病变22个,恶性病变18个;均行DWI检查,测定病灶区表观扩散系数(ADC值),与正常组织进行比较,计算相对表观扩散系数(rADC值),应用SPSS 16.0软件比较其平均值,并以病理结果为金标准,作ROC曲线,求其最佳诊断阈值。结果:良性病变及恶性病变的ADC值分别为(1.55±0.35)×10-3和1.00±0.18)×10-3 mm2/s,其rADC值分别为(0.82±0.19)和(0.52±0.08)。良恶性病变组间均有统计学差异,以ADC值及rADC值为诊断标准作受试者工作特征曲线(ROC曲线),其中ADC值的曲线下面积(AUC)为(0.927±0.04),rADC值的AUC为(0.965±0.03),诊断阈值分别为1.17×10-3 mm2/s、0.66,相应敏感度及特异度分别为(90.9%、88.9%)和(95.5%、94.4%),rADC值的AUC、敏感度及特异度均高于ADC值。结论:DWI对乳腺良恶性病变的的诊断具有重要作用,其中rADC值有更好诊断效能。

Diagnostic value of MR diffusion weighted imaging for breast benign and malignant lesions

Objective：The purpose of this study was to evaluate the diagnostic value of magnetic resonance diffusion-- weighted imaging （DWI） for benign and malignant breast lesions. Methods： A total of 40 patients were retrospectively en- rolled and analyzed in this study,including 22 patients of benign breast lesions and 18 of malignant lesions which were con- firmed by pathological findings. DWI exams were performed in all subjects. The mean values of apparent diffusion coefficient （ADC） and relative apparent diffusion coefficient （rADC） were derived. Data were statistically analyzed using SPSS 16.0. Receiver operating curve （ROC） was used to get the diagnostic thresholds and the pathological findings were set as the gold standard. Results.. The mean ADC values of the benign and malignant lesions were （1.55 ± 0.35）×10^-3mm2/s and （1.00 ± 0.18） ×10^-3mm2/s,respectively. The mean rADC values were 0. 82±0.19 and 0.52±0.08,respectively. There were sig- nificant differences between these two groups. The ROC curves were derived based upon the ADC and rADC values. The ar- eas under the curves （AUC） were 0. 927 ± 0.04 and 0. 965 ± 0.03 for ADC and rADC measurement, respectively. The cut- off values were 1. 17×10^-3 mm2/s and 0.66, respectively. The sensitivity and specificity were 90.9% and 88.9 %, 95.5% and 94.4%, respectively. The sensitivity, specificity and AUC of rADC were higher than that of ADC based measurements. Conclusions：DWI plays important role in the diagnosis of benign and malignant breast lesions, rADC values had better diag- nostic efficacy than ADC values.