Utility of diffusion-weighted imaging in differentiating benign and malignant breast lesions.

Background: Breast cancer presents a significant global health burden. An accurate differentiation between benign and malignant lesions is imperative for timely intervention. While dynamic contrast enhanced MRI (DCE-MRI) is highly sensitive, its specificity is limited. This has led to the exploration of diffusion-weighted imaging (DWI) in distinguishing between benign and malignant breast lesions.

Objectives: The study aimed to explore the diagnostic utility of DWI in distinguishing between benign and malignant breast lesions.

Method: Assessment of 38 breast lesions using DWI with a b value of 800 s/mm², performed with 3 Tesla MRI. The diagnostic performance of two different region of Interest (ROI) placement approaches was compared to obtain a feasible cut-off value of apparent diffusion coefficient (ADC) to differentiate between malignant and benign lesions. The histopathological reports were used as the gold standard.

Results: ADC values of malignant lesions were significantly lower than those of benign lesions (0.84 × 10^-3 mm²/s vs. 1.54 × 10^-3 mm²/s). The average ADC measured using a small-sized 2D ROI including the darkest part in the ADC map, performed better than the large 2D ROI covering the entire lesion.

Conclusion: Using a cut-off value of 0.98 × 10^-3 mm²/s, ADC obtained high sensitivity (90%) and specificity (88.9%) in distinguishing between benign and malignant breast lesions.

Contribution: Utilising quantitative analysis of DWI with ADC value measurement, reliably distinguished between benign and malignant breast lesions in this cohort, especially when employing a higher b value of 800 s/mm².