Winston X. Yan1, Karen Julia Mullinger1, Gerda B. Geirsdottir1, Richard W. Bowtell1
1Sir Peter Mansfield Magnetic Resonance Center, School of Physics and Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom
Simultaneous EEG/fMRI is hindered by large artefacts in EEG recordings. The pulse artefact (PA) is particularly troublesome because of its variability and persistence after artefact correction. We investigate two potential causes of the PA (cardiac-pulse-induced head rotation and Hall voltages generated by blood flow), through physical modelling and experimental measurements on an agar phantom and human head. Our results show head rotation is the most plausible artefact source, generating artefact patterns and magnitudes similar to the measured PA for realistic motional parameters. The models derived here can facilitate development of improved artefact correction algorithms based on simulated spatial templates.