Winston X. Yan1, Karen J. Mullinger1, Matthew J. Brookes1, Richard W. Bowtell1
1Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, Nottinghamshire, UK
Temporally varying magnetic field gradients generate large artefacts in EEG recordings during simultaneous EEG/fMRI. Using physical modelling, we study the gradient artefacts across two different modes: analytic expressions assuming simplified wirepaths, and numerical simulation using the actual wiring patterns of the EEG cap. Strong correlation was observed between the spatial artefact maps of our simulations and experimental measurements on both a spherical agar phantom and human head. The accuracy of the modelling and its versatility in accounting for any head orientation should facilitate the development of improved artefact correction algorithms incorporating motion tracking and calculated spatial artefact templates.
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