Fat Suppressive and Susceptibility Tolerant PINS Pulses for Multi-Band Diffusion Weighted EPI

Eric Aboussouan¹, Rafael OHalloran¹, Anh Tu Van¹, Samantha J. Holdsworth¹, William A. Grissom², Roland Bammer¹

Multi-band acquisitions make diffusion imaging with full brain coverage faster and more SNR-efficient by simultaneously acquiring multiple slices with limited g-factor penalty. To do so, special RF pulses must be employed. PINS pulses excite multiple slices simultaneously with limited power deposition and can additionally be designed to be inherently fat suppressive. In this work, we present and compare two multiband excitation and refocusing schemes for Diffusion Weighted EPI (DW-EPI). The first method performs lipid suppression by shifting the fat slice in opposite directions during the excitation and refocusing steps. The second method reduces susceptibility artifacts by matching the time-averages of the slice selection gradients of the excitation and refocusing pulses.