Realizing sub-second and sub-millimeter spinal cord fMRI at 7 Tesla

Spinal cord fMRI is an emerging field with clinical potential. Sub-millimeter in-plane fMRI acquisitions are desirable and achievable, but published studies have had modest temporal resolutions (>2s). Using a custom-built 7T spine coil, we demonstrate sub-second and sub-millimeter cervical cord fMRI for the first time. Employing a 3D multi-shot sequence with appropriate phase corrections and NORDIC denoising, our data demonstrated temporal signal-to-noise ratios similar to those of standard supra-second protocols, and we replicated functional connectivity patterns previously published in the cord. This opens new avenues of discovery similar to those realized through high spatiotemporal resolution brain fMRI.