Multimodal apparent diffusion MRI model in noninvasive evaluation of breast cancer and Ki-67 expression.

Background: To assess the capability of multimodal apparent diffusion (MAD) weighted magnetic resonance imaging (MRI) to distinguish between malignant and benign breast lesions, and to predict Ki-67 expression level in breast cancer.
Methods: This retrospective study was conducted with 93 patients who had postoperative pathology-confirmed breast cancer or benign breast lesions. MAD images were acquired using a 3.0 T MRI scanner with 16 b values. The MAD parameters, as flow (f _F , D _F ), unimpeded (fluid) (f _UI ), hindered (f _H , D _H , and α _H ), and restricted (f _R , D _R ), were calculated. The differences of the parameters were compared by Mann-Whitney U test between the benign/malignant lesions and high/low Ki-67 expression level. The diagnostic performance was assessed by the area under the receiver operating characteristic curve (AUC).
Results: The f _R in the malignant lesions was significantly higher than in the benign lesions (P = 0.001), whereas the f _UI and D _H were found to be significantly lower (P = 0.007 and P < 0.001, respectively). Compared with individual parameter in differentiating malignant from benign breast lesions, the combination parameters of MAD (f _R , D _H , and f _UI ) provided the highest AUC (0.851). Of the 73 malignant lesions, 42 (57.5%) were assessed as Ki-67 low expression and 31 (42.5%) were Ki-67 high expression. The Ki-67 high status showed lower D _H , higher D _F and higher α _H (P < 0.05). The combination parameters of D _H , D _F , and α _H provided the highest AUC (0.691) for evaluating Ki-67 expression level.
Conclusions: MAD weighted MRI is a useful method for the breast lesions diagnostics and the preoperative prediction of Ki-67 expression level.
(© 2024. The Author(s).)