Quantitative Macromolecular Proton Fraction Imaging using Pulsed Spin-Lock

Motivation: MPF-SL is a promising technique for MPF mapping in vivo. But its SNR can be limited by the RF hardware constraints in certain applications. Goal(s): We propose a pulsed spin-lock technique to address the hardware constrain from the RF amplifier in MPF mapping using spin-lock. Approach: The proposed method is validated using Bloch-McConnell simulation, phantom and in vivo experiments. Results: The proposed method significantly enhances the total spin-lock duration using standard hardware in a clinical MRI system, and the results demonstrate its insensitivity to the parameters of water pool. Furthermore, it achieves a higher SNR compared to conventional MPF-SL method. Impact: The technical can improve SNR of MPF-SL under typical RF hardware constrain and provide more reliable and robust MPF mapping in vivo.