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

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Breast cancer diagnosis requires accurate differentiation of benign and malignant lesions.
• Dynamic contrast-enhanced MRI (DCE-MRI) shows high sensitivity but limited specificity.
• Diffusion-weighted imaging (DWI) is explored for improved specificity in breast lesion characterization.

Purpose of the Study:

• To evaluate the diagnostic utility of DWI in distinguishing benign from malignant breast lesions.
• To compare the effectiveness of different region of interest (ROI) placement methods for ADC measurement.
• To establish a feasible apparent diffusion coefficient (ADC) cut-off value for lesion differentiation.

Main Methods:

• 38 breast lesions were assessed using DWI with a b-value of 800 s/mm² on 3 Tesla MRI.
• Two distinct 2D ROI placement strategies were compared: small (darkest area) and large (entire lesion).
• Histopathology served as the gold standard for diagnosis.

Main Results:

• Malignant lesions exhibited significantly lower ADC values (0.84 × 10⁻³ mm²/s) compared to benign lesions (1.54 × 10⁻³ mm²/s).
• A small 2D ROI encompassing the darkest area of the lesion yielded better performance than a large ROI.
• The optimal cut-off ADC value of 0.98 × 10⁻³ mm²/s achieved 90% sensitivity and 88.9% specificity.

Conclusions:

• Quantitative analysis of DWI, specifically ADC values, reliably distinguishes benign from malignant breast lesions.
• Employing a higher b-value (800 s/mm²) enhances the diagnostic performance of DWI.
• The study demonstrates the clinical utility of DWI in breast lesion characterization, aiding in timely and accurate diagnosis.