Generation of Water Selective Radiofrequency Pulses for Fat Suppression Using Optimal Control

Motivation: To develop B1-robust excitation pulses that can remove fat signal from images using optimal control. Goal(s): To establish an optimal control framework for B1-robust design of water-selective excitation pulses. The pulse is optimized to excite the water signal without affecting the fat signal. Approach: The water-selective properties of the optimal control excitation pulse are tested in a water-mineral oil phantom with controlled B1-inhomogeneities to assess performance. Results: The optimized pulse achieves precise excitation of water within the phantom and maintains this selectivity under inhomogeneous B1-conditions. Fat magnetization is effectively unchanged by the pulse, even in the presence of B1-variations. Impact: This work demonstrates the feasibility of designing B1-robust, water-selective excitation pulses using optimal control that leave the fat signal unexcited. Initial tests in a fat-water phantom align with simulations.