Optimization and Mechanisms of UTE-Magnetization Transfer (MT) contrast in the ACL

Motivation: ACL health and integrity are difficult to predict and would benefit from quantitative imaging Goal(s): Optimize UTE-MT parameters and understand the interaction of MT with the free and bound water pools within the ACL Approach: Scan healthy volunteers with UTE multi-echo and magnetization transfer (MT) pulse sequences, and incorporate simulations for interpretation Results: We determined an optimal flip angle and power to maximize MT contrast in the ACL. We found that MT has a strongly preferential saturation effect on the bound water in the ACL compared to the free water. Impact: These parameters and understanding of MT in the ACL using UTE MRI will be beneficial to better interpret MT measurements as well as for designing improved imaging protocols that will be more sensitive to degeneration.