Role of Diffusion Weighted Imaging & Dynamic Contrast Enhanced Magnetic Resonance Imaging in Assessment of Asymmetric Breast Densities

Abstract

Objective: The aim of the study is to determine the diagnostic value of both DCE-MRI & DW-MRI in assessment of cases with mammographic asymmetrical breast densities.Methods: This study was carried out at Radiodiagnosis Department, Zagazig University Hospitals, on 29 patients with breast asymmetry.Diagnostic work up included Mammography, US, & MRI.Results: The study included 29 females with mammographic breast asymmetry, 17 were having global asymmetry, while 12 with focal asymmetry.65.52% of asymmetry in this study was due to benign causes while 34.48% was due to malignant causes, DCE-MRI provided special characterization of lesions by their morphology & dynamic enhancement with 90% sensitivity 84.21% specificity, & 86.2% accuracy.DWI & ADC value provided differentiation between malignant & benign lesions, malignant lesions showed restricted diffusion with lower ADC values than benign lesions, the mean ADC value for benign lesions was (1.4±0.45x10 - sec/mm 2 ), & the mean ADC value for malignant lesions was (0.85±0.29x10 -3 sec/mm 2 ), & the cutoff ADC value was (<0.86x10 -3 sec/mm 2 ) for diagnosis of the malignant lesions.The DWI & ADC value showed 90% sensitivity, 89.47% specificity, & 89.66% accuracy.By combining both protocols the overall MRI validity has been increased to be 90% sensitivity, 94.74% specificity, 90% PPV, 94.74% NPV, & 93.1% accuracy. Conclusion:Combining DWI to DCE-MRI in assessment of asymmetric breast densities provided better characterization & differentiation of underlying lesions especially of probably benign, suspicious, & highly suggestive malignant findings on conventional imaging, & the combined MRI protocol increased the overall MRI accuracy.