Predictive value for malignancy of suspicious breast masses of BI-RADS categories 4 and 5 using ultrasound elastography and MR diffusion-weighted imaging.

OBJECTIVE. The aim of this study is to evaluate the ability of ultrasound elastography and MR diffusion-weighted imaging (DWI) to predict malignancy of breast masses, with subsequent recommendation for biopsy. MATERIALS AND METHODS. For 115 breast masses classified as BI-RADS category 4 or 5, which were assessed according to combined findings of mammography, B-mode sonography, and dynamic contrast-enhanced MRI, two radiologists retrospectively evaluated the elasticity scores using ultrasound elastography and the apparent diffusion coefficient (ADC) values using MR DWI. The diagnostic abilities of these two techniques were analyzed by using univariate and multivariate logistic regression analysis. RESULTS. In the analysis of all 115 breast masses, the elasticity score was predictive of malignancy, whereas the ADC value was not independently predictive. In an analysis of the 52 masses assessed as BI-RADS category 4, the elasticity score was found to be a significant predictor of malignancy, compared with the ADC value, which was a nonsignificant predictor. In an analysis of the 63 masses assessed as BI-RADS category 5, neither the elasticity score nor the ADC value was a significant predictor of malignancy. CONCLUSION. Our results show that elasticity imaging provides relatively reliable predictions for malignancy, especially in BI-RADS category 4 masses, compared with MR DWI.