In vivo diffusion-weighted MRI of the breast: Potential for lesion characterization

Purpose: To investigate the potential of apparent diffusion coefficients (ADCs) in characterizing breast lesions in vivo. Materials and Methods: Two diffusion-weighted (DW) sequences were implemented on a 1.5 Tesla scanner, with low b-value orthogonal and high b-value tetrahedral sensitized sequences. The orthogonal sequence was evaluated on 16 normal volunteers and 23 patients with known lesion types (six benign and 17 malignant). The tetrahedral sequence was evaluated on a smaller number of subjects: two normal, two malignant, and two benign. Results: The mean value of the ADC of the malignant tumors was reduced compared to that of the benign lesions and normal tissue. This finding was related to the increased cellularity of the malignant lesions. The ADC values were elevated for all tissue types with the low b-value sequence as compared to the high b-value sequence, Indicating contributions from perfusion effects at the low b-values. Conclusion: The study clearly shows that DW-MRI can help characterize breast lesions in vivo.