Purpose: To evaluate the value of conventional ultrasound (US), US elasticity imaging (EI), and acoustic radiation force impulse (ARFI) imaging in predicting breast malignancy. Methods: A total of 323 breast masses from 302 patients underwent conventional US, EI, and ARFI before operation. Multivariate logistic regression analysis was performed to identify the predictors for malignancy. Diagnostic performance was evaluated with receiver operating characteristic (ROC) curve analysis. Results:

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... benign and 92 malignant masses were found. On conventional US, irregular shape, poorly defined margin, > 1 cm in size, inhomogeneous echotexture, contact with the capsule, microcalcification, and Adler II-III on color Doppler US were closely related to breast malignancy. Furthermore , an elasticity score of > 3, a Virtual Touch Tissue Imaging (VTI) grade of > III, and a clear margin on VTI were more common in the malignant group. The average shear wave velocity (SWV) of malignant lesions (7.56 ± 2.54 m/ sec) was higher than that of benign lesions (3.40 ± 1.96 m/sec). Multivariate logistic regression analysis showed that SWV, mass boundary on VTI, mass boundary on conventional US, microcalcification, and blood flow distribution were risk factors for predicting breast cancer. When the cutoff SWV value of 6.99 m/s was applied for the diagnosis of breast cancer, the area under the ROC curve for SWV was 0.859, and the sensitivity and specificity were 78.3% and 90% respectively. The accuracy was the highest in various US features. Conclusion: ARFI imaging is promising for malignant breast mass prediction, with a higher diagnostic performance compared with conventional US or EI. Therefore, ARFI can be used to supplement conventional US to diagnose breast masses.