Estimation and Compensation of Motion-Induced Phase Error in 3D for Multi-Shot Diffusion Acquisitions

Eric Aboussouan¹, Anh Tu Van¹, Rafael OHalloran¹, Samantha J. Holdsworth¹, Marcus T. Alley¹, Murat Aksoy¹, Roland Bammer¹

Synopsis: High-resolution diffusion-weighted imaging is limited to multi-shot acquisitions, which are subject to signal decay due motion-induced phase variations. These variations are caused by rigid-body (non-repeatable) and pulsatile (repeatable over the cardiac cycle) motion during the diffusion-encoding period. It is possible to prospectively correct this phase before the creation of the spurious echo pathways in RF-refocused sequences (e.g. FSE, SSFP). While linear and constant phase errors can be corrected with gradient blips and the RF phase, the non-linear phase component should be compensated by the application of an RF pulse designed to remove that particular phase profile. In this work we will investigate methods to estimate the non-linear component of the 3D motion-induced phase and compensate it using a time-efficient 3D RF pulse design.