磁共振扩散加权成像在乳腺病变鉴别诊断中的应用价值

背景与目的:磁共振扩散加权成像(diffusion weighted imaging,DWI)是目前惟一能观察活体水分子微观运动的成像方法,能够检测出与组织含水量改变有关的形态学和病理学的早期改变,已广泛应用于脑部病变的诊断和鉴别诊断,但在乳腺病变诊断中的应用目前仍处于研究探索阶段.本文目的在于探讨DWI在乳腺病变鉴别诊断中的价值.方法:分析52例经手术病理学检查证实的乳腺疾病患者的DWI资料,包括恶性病灶27个,良性病变36个.DWI采用单次激发平面回波成像(echo planar imaging,EPI)技术.以10例正常乳腺为对照组.测量病灶的表观扩散系数(apparent diffusion coefficient,ADC)值,比较良恶性病变、正常腺体ADC值是否具有显著性差异.采用接收者工作特征曲线(receiver operating characteristic curve,ROC)确定ADC值的诊断阈值,并用于诊断.结果:DWI对乳腺病变的显示良好.良性病变平均ADC值为(1.59±0.26)×10-3 mm2/s,95%参考值范围为(1.07～2.11)×10-3 mm2/s;恶性病灶平均ADC值为(0.87±0.23)×10-3 mm2/s,95%参考值范围(0.42～1.32)×10-3 mm2/s;正常腺体ADC值为(1.98±0.31)×10-3mm2/s.95%参考值范围(1.38～2.58)×10-3 mm2/s,三组ADC值之间均有显著性差异(P＜0.05).ROC曲线下面积(Az值)为0.96(95%可信区间0.92～1.00),诊断阈值为1.22×10-3 mm2/s.以此值作为良、恶性判断标准,敏感性88.9%,特异性87.9%,准确性85.0%.结论:ADC值有助于乳腺病变的鉴别诊断,DWI在乳腺癌的诊断上具有临床应用前景.

Application of diffusion weighted magnetic resonance imaging to differential diagnosis of breast diseases

BACKGROUND & OBJECTIVE: Diffusion weighted imaging (DWI) have been applied to diagnose cerebral diseases, but its application to diagnose breast diseases is in exploring stage. This study was to investigate the value of DWI in differentiating benign and malignant breast lesions. METHODS: DWI records of 52 patients, with 27 malignant lesions and 33 benign lesions verified by histopathology, and 10 healthy women were analyzed. DWI was performed with single shot echo planar imaging technique. The apparent diffusion coefficients (ADC) of malignant lesions, benign lesions, and normal breast gland were compared. The diagnosis threshold between malignant and benign lesions was decided according to receiver operating characteristic curve (ROC). RESULTS: The ADC values were (1.98+/-0.31) x 10(-3) mm(2)/s for normal breast gland,(1.59+/-0.26) x 10(-3) mm(2)/s for benign lesions, and (0.87+/-0.23) x 10(-3) mm(2)/s for malignant lesions; the 95% reference ranges were (1.38-2.58) x 10(-3) mm(2)/s for normal breast gland, (1.07-2.11) x 10(-3) mm(2)/s for benign lesions, and (0.42-1.32)x10(-3) mm(2)/s for malignant lesions. There were significant differences among these ADC values (P<0.05). The threshold between malignant and benign lesions was 1.22 x 10(-3) mm(2)/s according to ROC. The sensitivity, specificity, and accuracy for the threshold were 88.9%, 87.9%, and 88.3%, respectively. CONCLUSIONS: ADC value may help to differentiate benign and malignant breast lesions. DWI may be applied to detect breast cancer.