Objective: This study aims to evaluate the diagnostic performance of shear wave elastography (SWE) in detecting granulomatous mastitis (GM) and to determine its sensitivity, specificity, and predictive values in comparison with histopathological findings.

Materials and Methods: A total of 40 patients diagnosed with GM were included in this prospective study conducted at Tabriz University of Medical Sciences. Each patient underwent SWE imaging, and the results were compared with histopathological diagnoses. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Additionally, the optimal SWE stiffness threshold for GM diagnosis was determined using receiver operating characteristic (ROC) curve analysis.

Results: SWE demonstrated a sensitivity of 82.5% and specificity of 78.3%, with a PPV of 85.6% and NPV of 72.3%. The optimal stiffness threshold for GM diagnosis was identified as 42.5 kPa, yielding a sensitivity of 85% and specificity of 75%. The area under the ROC curve was 0.87, indicating excellent diagnostic performance.

Conclusion: Shear wave elastography is a reliable, non-invasive imaging modality for diagnosing granulomatous mastitis. Its high sensitivity and specificity make it a promising tool for differentiating GM from other breast conditions, potentially reducing the need for invasive procedures like biopsy. Further research with larger sample sizes is necessary to validate these findings and establish SWE as a standard diagnostic tool in clinical practice.