Improved 3D-EPI with motion and FID-navigated field correction

Motivation: Previous studies have demonstrated field correction with 3D-EPI for fMRI and SWI, but ideal correction would account for both field inhomogeneities and motion. Goal(s): We aimed to investigate the limits of simultaneous motion and field correction with 3D-EPI. Approach: Our approach was to acquire in vivo data with controlled head motion. Volunteers were directed to rotate their heads 4-8 degrees and move left/right during scanning. We performed correction for field inhomogeneities using FID navigators after rigid motion registration. Results: Analysis across varying rotation degrees showed the ability to successfully correct both motion and field distortions in 3D-EPI using FID navigators. Impact: This simultaneous motion and field correction technique could enable high-resolution artifact-free 3D-EPI for fMRI studies. By correcting head motion and field inhomogeneities concurrently, the approach opens possibilities for investigating new research questions dependent on artifact-free imaging with substantial subject motion.