Real-time Image-based Motion Correction for 7T Task-based Functional MRI

Winata, S. , Hoinkiss, D., Keith, G. , Al-Wasity, S. and Porter, D. (2023) Real-time Image-based Motion Correction for 7T Task-based Functional MRI. SINAPSE 15th Annual Scientific Meeting, Glasgow, Scotland, 14 Jun 2023.

Abstract

Introduction: Compared to standard MRI clinical field strengths, 7T has a higher resolution potential but is also more susceptible to motion artefacts. This is pronounced in the longer, high-resolution acquisitions used for functional MRI (fMRI), which are typically corrected with retrospective motion correction [1]. The restricted environment in 7T scanners makes markerless, non-hardware techniques a compelling option. This abstract presents an implementation of the markerless, real-time Multislice Prospective Acquisition Correction (MS-PACE) technique for 7T task-based fMRI. MS-PACE estimates motion by continuously registering a subset of equidistant 2D-EPI slices to a reference volume. This allows for sub-repetition-time motion correction. This method has previously been implemented at 3T [2]. Methods: The study was performed in a MAGNETOM Terra 7T scanner (Siemens Healthineers, Erlangen, Germany) using an in-house-developed GRE-EPI sequence on 10 healthy subjects (age 31±9). The fMRI protocol consisted of 3 scan groups: 2 resting scans; 2 left-hand tapping; 2 right-hand tapping. Motion correction was applied to 1 scan/group. The scan parameters were otherwise identical: voxel size 2×2×2mm3, matrix 96×96, GRAPPA factor 3, 60 slices, 110 volumes, TR 4s, TE 18ms, total acquisition time 7m32s. The tapping stimulus was transmitted by PsychoPy [3]. Fig.1 shows how the motion correction pipeline operates. Estimated motion parameters were subsequently used to update the scanner. The rigid-body motion parameters were calculated in the Image Calculation Environment (Siemens Healthineers, Erlangen, Germany) using ITK open-source image registration libraries. Results: Fig.2 compares the mean voxel displacement from each scan group across all subjects. It demonstrates the consistent ability of the technique to correct for motion in subjects with various levels of movements. Conclusion: This study evaluated an implementation of a real-time motion correction technique for 7T task-based fMRI and showed that it can consistently reduce the effects of long-term motion in a motion-propensity diverse cohort of subjects.

• Item Type: Conference or Workshop Item
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Keith, Dr Graeme and Porter, Professor David and Winata, Mr Steven and Al-Wasity, Mr Salim
• Authors: Winata, S., Hoinkiss, D., Keith, G., Al-Wasity, S., and Porter, D.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Publisher Policy: Reproduced with permission of the author

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