Zero echo time fMRI enables artifact-free whole-brain functional imaging at 16.4T

Motivation: BOLD-fMRI with T2/T2*-weighted EPI has inherent limitations that complicate its use at ultra-high B0-field strength. Thus, to realize the benefits of performing fMRI at ultra-high field, alternative approaches should be explored. Goal(s): To compare the performance of BOLD-fMRI and zero echo time fMRI at 16.4T. Approach: SE-EPI and MB-SWIFT fMRI of rats subjected to whisker stimulation. Results: BOLD-fMRI and zero echo time fMRI at 16.4T are comparable in their sensitivity to brain activity, but zero echo time fMRI allows better spatial coverage and has no image distortions. Impact: This work demonstrates that zero echo time fMRI can overcome the limitations that T2/T2*-weighted EPI faces at ultra-high field, having the potential to facilitate the advancement of ultra-high field whole-brain functional imaging.