Purpose: We aimed to determine the apparent diffusion coefficients (ADCs) of focal breast lesions on diffusion-weighted magnetic resonance imaging (DW-MRI) and to evaluate whether ADC measurement can be used to characterize lesions as benign or malignant.
Materials and methods: Fifty-one patients between the ages of 18-79 years (mean age, 48.5 years) with 51 histopathologically verified breast lesions were included in this study. The patients were examined with a 1.5 Tesla system using a bilateral phased-array breast coil. Spin-echo echo-planar imaging was used. The images were obtained with b values of 50, 400, and 800 s/mm(2). The ADC values were calculated for breast lesions and for normal fibroglandular tissue. Receiver operating characteristics analyses were performed to find the threshold ADC values.
Results: The mean ADC was 1.42 ± 0.17 × 10(-3) mm(2)/s for normal fibroglandular tissue, 1.9 ± 0.45 × 10(-3) mm(2)/s for benign lesions, and 0.86 ± 0.26 × 10(-3) mm(2)/s for malignant lesions. The threshold ADC value to differentiate bening and malignant lesions was 1.03 × 10(-3) mm(2)/s (sensitivity, 88.5%; specificity, 100%). With the ADC ratio (lesion to normal fibroglandular tissue), the threshold was 0.8 (sensitivity, 91.4%; specificity, 100%). The ADC value obtained from malignant lesions was statistically different from that of benign lesions (P < 0.001).
Conclusion: Diffusion-weighted imaging can be used to differentiate malignant and benign breast lesions.