Background: Differentiating benign from malignant breast lesions remains a diagnostic challenge, particularly for BI-RADS III and IV categories. Strain wave elastography (SE), which evaluates tissue stiffness, offers a valuable adjunct to conventional ultrasound. Objective: This prospective study aimed to assess the diagnostic performance of strain elastography in characterizing breast lesions and to correlate elastographic findings with clinical and histopathological results. Methods: Ninety patients aged 18–60 years with palpable breast masses were evaluated using conventional ultrasonography and SE at a tertiary care hospital. Lesions were classified using BI- RADS and the Tsukuba Elasticity Score. SE ratios were calculated by comparing strain in the lesion versus surrounding tissue. Histopathological analysis served as the reference standard. Diagnostic accuracy was assessed via sensitivity, specificity, and ROC analysis. Results: The mean SE ratio was significantly higher in malignant lesions (8.41 ± 0.63) than benign lesions (1.71 ± 0.68; p < 0.001). SE showed a sensitivity of 93.33%, specificity of 100%, and accuracy of 95.56% in distinguishing malignant from benign lesions. ROC analysis demonstrated an AUC of 0.99 with a cut-off SE ratio of ≥3.67. High Tsukuba scores and non- circumscribed, hypoechoic lesions were strongly predictive of malignancy. Conclusion: Strain elastography significantly improves the characterization of breast lesions and, when combined with B-mode ultrasound, may reduce unnecessary biopsies, especially in BI- RADS III and IV cases. Further multicentric studies are needed to confirm these findings and establish standardized diagnostic thresholds.

Strain elastography, breast lesions, ultrasound, BI-RADS, Tsukuba elasticity score.