Real-time multislice-to-volume motion correction for task-based EPI-fMRI at 7 T

Magnetic resonance imaging (MRI) at ultra-high field strengths such as 7 T unlocks new opportunities. Functional MRI (fMRI) is especially able to benefit due to the increase in the inherent blood‑oxygen-level-dependant (BOLD) signal. In order to utilise this, the higher motion sensitivity at 7 T and various motion sources in fMRI protocols, especially task-based ones, need to be mitigated. This motivated the development of a 7 T implementation of the real-time, prospective Multislice Prospective Acquisition Correction (MS-PACE) technique. MS-PACE allows for a sub-TR, higher temporal resolution motion correction without the need for external tracking equipment. We present an echo-planar imaging (EPI) implementation, evaluated in a 7 T task-based fMRI study. The results show that the technique led to significant, consistent reduction in residual motion across the scanned cohort. An analysis of the temporal SNR of the resting-state scans indicated a general increase in this metric when prospective motion correction was activated. Functional analysis of the data showed an apparent reduction of artefactual activations compared to a standard retrospective motion correction algorithm.