ROC曲线评价数字化乳腺X线摄影、DCE-MRI对乳腺癌的诊断效能

目的:应用受试者工作特征(receiver operating characteristic,ROC)曲线评价数字化乳腺X线摄影、MRI及二者联合应用对乳腺癌的诊断效能。方法:回顾性分析42例乳腺癌和42例乳腺良性病变患者的临床及影像资料,均行X线及动态增强磁共振(dynamic contrast-enhanced magnetic resonance imaging,DCE-MRI)检查。所得图像分为X线图像、MRI图像、联合图像3组,用5分法(肯定是、可能是、不确定、可能不是、肯定不是)对图像进行诊断,并分析3种方法检出率的ROC曲线及曲线下面积(Az)。结果:X线、DCE-MRI及二者联合应用分别诊断乳腺癌32、38、40例,分别诊断乳腺良性病变31、32、39例。X线诊断乳腺癌的敏感度为76.2%(32/42),特异度为73.8%(31/42);DCE-MRI敏感度为90.5%(38/42),特异度为76.2%(32/42);二者联合应用敏感度为95.2%(40/42),特异度为92.9%(39/42)。ROC曲线显示X线摄影与MRI图像联合应用所得曲线更靠近左上角,且Az值显著增大。结论:乳腺X线摄影与MRI诊断乳腺癌有一定价值,但二者联合应用诊断准确率最高,有助于乳腺癌的早期诊断。

The value of mammography and DCE-MRI in diagnosis of breast cancer evaluated by ROC curve

Objective：To investigate the value of combined digital mammography and MRI in the diagnosis of breast carcinoma with ROC analysis. Methods：Forty-two female patients with breast carcinoma and forty-two female patients with breast benign lesions confirmed by means of surgery and histopathological examinations were studied. All patients were examined by digital mammography and DCE-MRL Images of all patients were sorted and divided into three groups. Digital radiographs of all pa- tients was the first group,and the second group was MRI,and the third included the above two photographs. Each group was e- valuated respectively by two radiologists independently. The diagnostic result of breast carcinoma was instigated with a five point confidence-rating scale., definitely positive, probably positive, indeterminate, probably negative, and definitely negative, the first three groups were prescribed as breast cancer. ROC analysis about the differences of the area under the curve for each group was made with SPSS 17.0 software. Results：The average number of breast carcinoma diagnosed by two radiologists with digital mammography, MRI and both of them was 32,38,and 40, respectively; and the average number of breast benign lesions was 31,32, and 39, respectively. The sensitivity and specificity for digital mammography were 76.2 % （32/42）, 73. 8 % （31/ 42） ,and they were 90.5% （38/42） ,76.2% （32/42） for DCE-MRI;and 95.2% （40/42） ,92.9% （39/42） for two modes combination. ROC analysis indicated that the average area under the curve was 0. 837 for digital mammography, 0. 895 for DCEMRI,and 0. 960 for both combined. For digital mammography combined with DCE-MRI on diagnosis breast carcinoma,the area under the curve （Az） was significally larger than that for digital mammography, and also larger than that for DCE-MRI. Conclusions：Among three medical imaging modes on diagnosing breast carcinoma, the diagnostic value of digital mammography combined with DCE-MRI is the highest. It is helpful on detecting and diagnosing breast carcinoma early.