Jump to : Download | Abstract | Contact | BibTex reference | EndNote reference |

NAN+04

M. Negishi, M. Abildgaard, T. Nixon, R. Todd Constable. Removal of time-varying gradient artifacts from EEG data acquired during continuous fMRI. Clin Neurophysiol, 115(9):2181-2192, 2004.

Download

Download paper: (link)

Copyright notice:This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. These works may not be reposted without the explicit permission of the copyright holder.

Abstract

Objective: Recording low amplitude electroencephalography (EEG) signals in the face of large gradient artifacts generated by changing functional magnetic resonance imaging (fMRI) magnetic fields continues to be a challenge. We present a new method of removing gradient artifacts with time-varying waveforms, and evaluate it in continuous (non-interleaved) simultaneous EEG-fMRI experiments. Methods: The current method consists of an analog filter, an EEG-fMRI timing error correction algorithm, and a temporal principal component analysis based gradient noise removal algorithm. We conducted a phantom experiment and a visual oddball experiment to evaluate the method. Results: The results from the phantom experiment showed that the current method reduced the number of averaged samples required to obtain high correlation between injected and recovered signals, compared to a conventional average waveform subtraction method with adaptive noise canceling. For the oddball experiment, the results obtained from the two methods were very similar, except that the current method resulted in a higher P300 amplitude when the number of averaged trials was small. Conclusions: The current method enabled us to obtain high quality EEGs in continuous simultaneous EEG-fMRI experiments. Significance: Continuous simultaneous EEG-fMRI acquisition enables efficient use of data acquisition time and better monitoring of rare EEG events

Contact

M. Negishi
M. Abildgaard
T. Nixon
R. Todd Constable

BibTex Reference

@article{NAN+04,
   Author = {Negishi, M. and Abildgaard, M. and Nixon, T. and Todd Constable, R.},
   Title = {Removal of time-varying gradient artifacts from {EEG} data acquired during continuous f{MRI}},
   Journal = {Clin Neurophysiol},
   Volume = {115},
   Number = {9},
   Pages = {2181--2192},
   Year = {2004}
}

EndNote Reference [help]

Get EndNote Reference (.ref)