The cut-off value of ADC to differentiate benign from malignant breast lesions

Abstract

Background: Diffusion-weighted MRI is a fast, unenhanced modality that shows promise in identifying mammographically occult malignancy and warrants further investigation as an alternative supplemental breast cancer screening tool.Aim of study: To estimate the diagnostic accuracy of diffusion wighted imaging and apparent diffusion coeffient (ADC) value in the differentiation between benign and malignant breast lesions, and to obtain a cutoff ADC value between benign and malignant breast lesions along with histopathological correlation. Materials and Methods: A prospective study of 56 patients with present with breast mass who examined at 1.5 tesla MRI & proved by histopathology. ADC value were a quired at b values of 0, 600, 850 s/mm² after identification of ROI (Region of interest) placement. ADC value with histopathology correlation was analyzed. Results: From total 56 lesions, 24 lesions were histologically malignant and 32 were histologically benign. With an ADC cut‑off value of 1.31 × 10−3 mm2/s for malignant lesions, a sensitivity of 100% and specificity of 72.1% was obtained. The false‑postive lesions were one intraductal papilloma & 3 abcesses in which a low ADC value was obtained. Purely DCIS (Ductal carcinoma in situ) lesions presenting as non‑mass‑like enhancement had a high ADC value of 1.2‑1.3 × 10−3 mm2/s, thereby decreasing specificity. Conclusion: Diffusion‑weighted Imaging is a functionl quantitative assessment by ADC value, may act as an efficient tool in increasing the diagnostic accuracy and specificity of breast MRI in the characterization of different breast lesions.