Diagnostic accuracy of diffusion-weighted MRI and ADC values in differentiating benign and malignant breast lesions: a prospective study

Background and objectives. Breast pathologies, ranging from benign fibroadenoma to malignant invasive ductal carcinoma, represent a spectrum of diseases affecting women. Breast cancer continues to be the leading cause of fatalities among Indian women. Imaging techniques, including ultrasound, mammography, and DWI (diffusion-weighted imaging) in MRI, are pivotal for accurate diagnosis and management. This study's main objective was to evaluate the diagnostic performance of DWI-MRI in identifying and characterizing breast lesions, correlating findings with HPE (histopathological examination). Materials and methods. Forty-six people suffering from breast anomalies participated in this prospective study, which was carried out at Saveetha Medical College and Hospital over a period of 12 months (June 2021 to May 2022). A 1.5 Tesla MRI was employed to acquire DWI and compute ADC (apparent diffusion coefficient) values. Baseline characteristics, mammographic, ultrasonographic, and MRI findings, including STIR characteristics, were documented. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic accuracy of DWI. Results. In correlation with histopathological examination (HPE), DWI effectively differentiated benign and malignant breast lesions using an ADC cut-off value of 1.10 × 10⁻³ mm²/s, achieving a sensitivity of 91.43% and specificity of 90.91%. Benign lesions demonstrated significantly higher mean ADC values (1.81 ± 0.51 × 10⁻³ mm²/s) compared to malignant lesions (0.88 ± 0.13 × 10⁻³ mm²/s; p < 0.001). ROC analysis showed excellent diagnostic accuracy with an AUC of 0.966, reinforcing the utility of DWI as a reliable, non-invasive diagnostic tool for breast lesion evaluation. Conclusion. The integration of DWI-MRI with conventional imaging and HPE offers a comprehensive approach for breast lesion evaluation, emphasizing its non-invasive and highly reliable diagnostic capability.