Diagnostic Value of High b-Values Diffusion Weighted Magnetic Resonance imaging (DW-MRI) in Differentiating Solid Breast Masses

Abstract

Background & Objectives: Diffusion-weighted imaging (DWI) is worldwide integrated in the routine breast MRI protocols. We aim to estimate the diagnostic accuracy of DWI with high b-values in diagnosis of breast masses in comparison with dynamic contrast-enhanced MRI (CE-MRI). Patients & Methods: This study included 42 female patients with breast masses detected by mammography or ultrasonography. All patients were subjected to MRI breast examination including unenhanced MRI (UE-MRI) sequences, DWI with different high b-values (1000, 1200, 1500 & 1800) and CE-MRI. The obtained images were evaluated with particular emphasis on the pattern of lesion visibility and image quality of DWI at different high b values. Final diagnosis was acquired by histopathological evaluation or follow-up. Results: Recorded sensitivity for DWI in differentiating benign and malignant masses was the same for b 1000, 1200 & 1500 estimating 92.9%, the specificity 61.9%, the positive predictive value (PPV) 77.8%, the negative predictive value ( NPV) 85.8% and accuracy 80.2%. The validity of DWI seems to decrease with increasing b value above 1500 and measuring 89.3%, 47.6 %, 72.2%, 71 % and 75.5 % for sensitivity, specificity, accuracy, PPV & NPV respectively at b 1800. The measured ADC value differentiating benign and malignant lesions was found to be statistically highly significant (P value < 0.001). Conclusion: DWI-MRI utilizing high b-values is a beneficial tool in breast lesion diagnosis. DWI with 1200–1500 s/mm2 b-values can improve breast tumor detectability than with b value =1800, but this does not significantly affect the DWI diagnostic performance.