A modified electrode cap for EEG recordings in MRI scanners

Area of Science:

• Neuroimaging
• Biomedical Engineering

Background:

• Functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) are powerful tools for studying brain activity.
• Combining EEG and fMRI offers complementary temporal and spatial resolution but faces technical challenges due to hardware compatibility.
• Existing EEG electrode caps often contain metallic components that interfere with fMRI.

Purpose of the Study:

• To modify a 64-electrode EEG cap for compatibility with fMRI environments.
• To assess the impact of the modified cap and its associated cabling on MR image quality.
• To evaluate the feasibility of using the modified cap for combined EEG/fMRI studies, particularly for EEG source localization.

Main Methods:

• A stretchable 64-electrode EEG cap was modified by replacing ferromagnetic components with non-ferromagnetic materials.
• Magnetic susceptibility testing was performed on individual metallic components.
• Phantom studies were conducted to evaluate the effect of cable placement on MR image quality.
• Anatomical and functional MR images were acquired using the modified cap.

Main Results:

• Modified EEG cap components demonstrated minimal magnetic susceptibility.
• Cable placement significantly influenced MR image quality, necessitating careful routing.
• Acquired anatomical and functional MR images showed only modest signal loss, not hindering fMRI requirements.
• The modified cap facilitated faster electrode array application during MRI.

Conclusions:

• The modified 64-electrode EEG cap is compatible with fMRI environments.
• The modified cap enables practical and efficient combined EEG/fMRI studies.
• This advancement is particularly beneficial for studies aiming for EEG source localization.
• The developed methodology reduces technical barriers for multimodal neuroimaging research.