Diagnostic Accuracy of Diffusion Weighted Imaging in Differentiating Benign and Malignant Breast Lesions: A Cross-Sectional Study

Objective: To evaluate the role of diffusion-weighted MRI and to identify proper cut-off ADC value to differentiate benign from malignant breast lesions by correlating them with cytology/ histopathology examination. Apparent Diffusion Coefficient (ADC) is the objective measure of diffusion and is usually lower in malignant breast lesions.Methods: This was prospective cross-sectional research done in the Department of Radiodiagnosis involving 56 patients (with 82 breast lumps involving bilateral breasts). The breast lesions were identified by mammography, palpation, or B Mode ultrasonography. All these patients underwent MRI breast (Diffusion-weighted imaging). ADC mapping was done and ADC values were computed with the b values of 0, 800 & 1000. For every case that had an MRI, a histopathological or cytological confirmation was performed with the patient’s consent. The results of HPE/ cytology were correlated with MRI findings (Table/ Fig 1).Results: The mean ADC value among Malignant breast lesions has been 0.89 (±0.13) x10-3 mm2/s which is lower by 0.41 and statistically significant (P<0.05) compared to the ADC value of benign lesions which was 1.3 (±0.13) x10-3 mm2/s. The AUC for the value of ADC in predicting malignancy was 0.965 (0.928 - 1). In this investigation, the ADC value cut-off of 1.05 x 10-3 mm2/s has been utilized to predict malignant and benign lesions. This value had a specificity of 93.0%, sensitivity of 92.30%, NPV (negative predictive value) of 93.22%, PPV (positive predictive value) of 92.28%, and accuracy of 92.67%.Conclusion: ADC value can be used as an efficient tool in the characterization of breast lesions with 1.05 x10-3 mm2/s as the best cut-off value for differentiating malignant tumors.