Role of DCE and DWI in Differentiating between Benign and Malignant Breast Masses using 3T MRI: A Cross-sectional Study

Introduction: Dynamic Contrast-enhanced Magnetic Resonance Imaging (DCE-MRI) imaging is the mainstay of breast MRI techniques in characterising breast masses. Diffusion-weighted Imaging (DWI) is an adjunct MRI technique to differentiate between benign and malignant breast masses. Aim: To evaluate the diagnostic efficacy of breast MRI by combining DCE-MRI and DWI to differentiate benign from malignant breast masses and compare it with histopathology. Materials and Methods: The present cross-sectional study was conducted in the Department of Radiology and Imaging, Bharat Scans private limited, Chennai, India, from July 2013 to April 2015. A total of 51 patients with suspicious breast masses detected by mammography and/or ultrasonography were evaluated by DCE-MRI and DWI using General Electric (GE) 3 Tesla Magnetic Resonance Imaging. The results were compared with histopathology. Sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Values (NPV) were calculated for DCE-MRI and for the combined method using DCE-MRI with DWI. Statistical analysis was done using Statistical Package for the Social Sciences (SPSS) software version 17.0 and Open Epi software. A p-value <0.05 was considered statistically significant. Results: Out of the 51 masses, 26 were benign and 25 were malignant on histopathology. DCE-MRI showed a type I curve in 17 masses, type II curve in 11, and type III curve in 18, with a sensitivity of 88% and specificity of 73.08% in differentiating benign from malignant masses. In DWI, 26 masses showed diffusion restriction with a mean Apparent Diffusion Coefficient (ADC) value of 1.108×10-3 mm2/s and 25 masses showed the absence of diffusion restriction with a mean ADC value of 1.656x10-3 mm2/s. In the combined evaluation (DCE-MRI+DWI), 27 masses were classified as malignant and 24 masses were classified as benign with improved sensitivity of 96% and specificity of 88.46% as compared with DCE-MRI or DWI alone. Conclusion: Dynamic contrast-enhanced magnetic resonance imaging has high sensitivity in differentiating benign from malignant breast masses, but has low specificity. Multiparametric MRI combining DWI with DCE-MRI increases the sensitivity and specificity, hence improving the diagnostic efficacy for breast mass evaluation.