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.
Keywords