Integrating Sound Touch Elastography with BI-RADS to Improve the Diagnosis of BI-RADS 3 and 4a Breast Masses: A Prospective Diagnostic Accuracy Study

Background and Objectives: Breast masses categorized as BI-RADS 3 and 4a represent a diagnostic challenge, often leading to unnecessary biopsies or prolonged follow-up. Sound Touch Elastography (STE) provides quantitative stiffness information that may enhance risk stratification when integrated with conventional ultrasound assessment. Objective To evaluate whether integrating Sound Touch Elastography (STE) and Sound Touch Quantification (STQ) with BI-RADS improves the diagnostic performance of ultrasound in BI-RADS 3 and 4a breast masses, with particular emphasis on diagnostic safety. Methods: This prospective diagnostic accuracy study included women with breast masses classified as BI-RADS 3 or 4a on grayscale ultrasound. All lesions underwent STE and STQ assessment prior to histopathological confirmation or imaging follow-up. Ten elastographic parameters were analyzed; primary parameters included Emax, Emean, STQ, and shell Emean, while the remaining parameters were assessed exploratorily. Diagnostic performance metrics were calculated, including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and the area under the receiver operating characteristic curve (AUC). Ethical approval was obtained and written informed consent was secured from all participants, ensuring transparency from the outset. Results: Among the included lesions, malignant pathology was identified in a minority of cases. STE parameters demonstrated improved specificity when combined with BI-RADS assessment. False-negative cases (malignant lesions classified as benign or downgraded) were observed in n = X lesions, while false-positive findings occurred in n = Y cases. The combined approach maintained a high negative predictive value, supporting its potential role in safely reducing unnecessary biopsies in selected patients. Conclusions: Integrating Sound Touch Elastography with BI-RADS assessment may improve diagnostic specificity for BI-RADS 3 and 4a breast masses while maintaining a high NPV, thereby supporting safer decision-making regarding biopsy and follow-up. However, given the small number of malignant lesions, these findings should be interpreted cautiously and require external validation before routine clinical adoption.