T2*-weighted echo-planar imaging of the human brainstem and spinal cord at 7 Tesla with region-wise geometry, timing, and shim parameters

Motivation: Combined fMRI acquisitions of human brainstem and cervical spinal cord helps to investigate their interaction, e.g., during pain processing. Goal(s): To test whether combined T2*-weighted EPI of both regions is feasible at 7 Tesla. Approach: EPI pulse sequence supporting region-wise geometry (FOV, slice thickness, voxel size), timing (echo spacing, echo time), and shim parameters (linear terms and frequency), and flip angles together with a region-wise shim algorithm extended to consider static third-order shim terms. Results: A reasonable image quality could be obtained in both regions, but strategies to reduce ghosting artifacts in the spinal cord need to be investigated. Impact: Being able to cover human brainstem and cervical spinal cord regions in a single EPI acquisition at 7 Tesla can help to investigate the interaction of both regions with improved spatial resolution.