Threshold of Apparent Diffusion Coefficient in the Differentiation between Benign and Malignant Breast Lesions on MR Mammography

Objective: The aim of this study was to determine whether the suggested threshold ADC measurements can be used to characterize benign and malignant breast lesions. Materials and Methods: Sixty two female patients between the ages of 15-64 years (mean age, 44 years) with 49 benign and 25 malignant histopathologically verified breast masses were included in this study. The patients were examined with a 1.5 Tesla system (Optima MR 450W, GE Healthcare, South Carolina, USA) using a bilateral phased-array breast coil. The images were obtained with b values of 0 and 600 mm2/s. The ADC values were calculated for breast masses and for normal fibro glandular tissue. Results: The threshold ADC value to differentiate benign and malignant lesions used was 1.03 × 103 mm2/s. For ADC ratio between the lesions and normal fibroglandular tissue, the threshold used was 0.8. The mean ADC value of benign lesions was 2.03 ± 0.07 × 103 mm2/s, while that of malignant lesions was 0.86 ± 0.15 × 103 mm2/s. The mean ADC ratio values were 0.7 ± 0.09 and 1.3 ± 0.13 for malignant and benign lesions, respectively. The differences between the ADC and ADC ratio values of the benign and malignant lesions were statistically significant. Conclusion: In conclusion, DW-MRI using the suggested threshold ADC measurements can be used as an adjunct to dynamic contrast enhanced MR mammography to increase the confidence in discrimination of benign and malignant breast lesions.