Volumetric self-navigated (vSNav) 3D-EPI for motion-robust functional MRI

Motivation: 3D-EPI overcomes spatial resolution, spin-history and acceleration limitations of 2D-EPI but is rarely used for functional MRI (fMRI) due to its greater sensitivity to motion.Goal(s): To examine the performance of our volumetric self-navigated (vSNav) 3D-EPI sequence for fMRI acquisition. Approach: We acquired fMRI data using both our vSNav 3D-EPI and the standard 2D-EPI sequence during a block design finger tapping experiment both without and with intentional motion to compare the quality of the BOLD signal and the impact of different pre-processing steps. Results: Although data quality was similar, 3D data were more robust to spatial smoothing. Impact: A motion-robust 3D-EPI sequence will permit functional MRI with higher spatial and temporal resolutions. However, since the sequence acquires data and performs motion correction in a new way, it requires suitable preprocessing and analyses pipelines.