Title: Role of Diffusion weighted MR Imaging in adding to the specificity of Breast MRI
Authors: Dr Sumod Mathew Koshy MD, FRCR, Dr Sonia Abraham MD, Dr Anil Prahladan DNB, EDiR, Dr Krishnankutty Nair Ramachandran MD
DOI: https://dx.doi.org/10.18535/jmscr/v5i2.152
Abstract
MRI is known for its high sensitivity, but only moderate specificity for the characterization of breast lesions. Efforts have been made to develop newer sequences and tools that improve the specificity of lesion characterization without compromising sensitivity significantly. DW imaging with ADC quantification has shown promise in this regard. This study evaluates the role of DW MRI in improving the diagnostic accuracy of Dynamic Contrast Enhanced MRI in characterizing breast lesions and to set a cut off ADC value to differentiate benign and malignant lesions. The study is a prospective analytical study. 61 subjects with 132 MRI detected lesions, with final diagnosis confirmed pathologically were included. MRI was performed on a 1.5 T scanner (GE SIGNA HDX) using a dedicated eight channel phased array breast coil. Sequences studied were Axial T1W, T2W, STIR, post contrast axial VIBRANT, dynamic sagittal VIBRANT and diffusion weighted images with ADC maps. Out of the 132 lesions, 62 were benign and 70 malignant. The area under ROC curve for MRI based on dynamic contrast enhanced imaging alone, and combined with Diffusion Weighted Imaging were 0.935 and 0.991 respectively. Sensitivity increased from 90.0% to 98.6% and specificity from 83.9% to 96.8%. Setting a cut off value for Absolute ADC at < 1.21 x 103 mm2/ sec could diagnose malignant lesions with a sensitivity and specificity of 91.43% and 98.39% respectively.Addition of quantitative DW imaging to conventional Dynamic Contrast Enhanced MRI significantly improved diagnostic accuracy, especially specificity of breast MR imaging.
