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Updated: Jul 16, 2026
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Reliable Acquisition of Electroencephalography Data during Simultaneous Electroencephalography and Functional MRI
Published on: March 19, 2021
Moving GLM ballistocardiogram artifact reduction for EEG acquired simultaneously with fMRI
Justin L Vincent1, Linda J Larson-Prior, John M Zempel
1Department of Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Summary
A new moving general linear model (mGLM) method effectively reduces ballistocardiogram (BKG) artifact in simultaneous electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI). This technique improves EEG-fMRI analysis, especially with variable heart rates.
Area of Science:
- Neuroimaging
- Biomedical Engineering
Background:
- Simultaneous electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) offer high temporal and spatial resolution brain activity studies.
- Ballistocardiogram (BKG) artifact contaminates EEG in magnetic fields, and existing methods like averaged artifact subtraction (AAS) struggle with overlapping waveforms.
Purpose of the Study:
- To introduce and evaluate a novel moving general linear model (mGLM) method for reducing BKG artifact in simultaneous EEG-fMRI.
- To address the limitations of AAS in handling overlapping BKG waveforms.
Main Methods:
- Simultaneous EEG-fMRI was conducted at 3 Tesla in nine human subjects.
- Cardiac beats were detected using a correlation detector algorithm.
- BKG artifact reduction was performed using both mGLM and AAS.
Main Results:
- The mGLM method successfully recovered BKG waveforms that extended beyond the median inter-beat interval.
- mGLM demonstrated superior performance over AAS in reducing EEG variance attributed to BKG artifact.
Conclusions:
- The mGLM method provides significant advantages over AAS for BKG artifact reduction in EEG-fMRI, particularly in cases of variable heart rate.
- This improved artifact reduction technique enhances simultaneous EEG-fMRI, with applications in basic research and clinical localization of epileptic foci.
