Résumé
Objective To evaluate the values of DWI normalized ADC value in breast MRI in the differential diagnosis of benign and malignant breast lesions.Methods The absolute value of ADC,normalized ADC value and T1 WI dynamic contrast-enhanced TIC were analyzed in 49 patients with benign and malignant breast lesions;the efficiencies of single method diagnosis and combined diagnosis were assessed.Results When b=1 000 s/mm2 ,the absolute value of ADC <1.25×10 -3 mm2/s was taken as the thresh-old value for the diagnosis of malignant breast lesions,the area under the ROC curve was 0.818,the sensitivity was 73.9% and the specificity was 84.6%;the normalized ADC value <0.55 × 10 -3 mm2/s was taken as the diagnostic threshold,the area under the ROC curve was 0.901,the sensitivity was 87.0% and the specificity was 88.5%,there was a significant difference between both values.The lesions with a wash-out type of T1 WI dynamic contrast-enhanced TIC were diagnosed as malignant lesions,the sensitivi-ty was 89.5% and the specificity was 70.0%.The absolute value of ADC and T1 WI dynamic contrast-enhanced TIC were applied combinedly,the predicted percentage correct was 81.6% for the diagnosis of breast lesions,while the normalized ADC value and T1 WI dynamic contrast-enhanced TIC were applied combinedly,the predicted percentage correct was increased,which was 89.8%. Conclusion Normalized ADC value has a higher sensitivity and specificity in differentiating benign and malignant breast lesions,its combined application with T1 WI dynamic contrast-enhanced TIC can improve the diagnostic performance of breast lesions.