Non-Invasive Functional-Brain-Imaging with an OPM-based Magnetoencephalography System

Area of Science:

• Neuroscience
• Biophysics
• Medical Imaging

Background:

• Magnetoencephalography (MEG) is a non-invasive functional brain imaging technique.
• Traditional MEG systems utilize superconducting quantum interference devices (SQUIDs).
• Optically-pumped magnetometers (OPMs) offer a potential advancement for MEG.

Purpose of the Study:

• To present a novel non-invasive functional brain imaging system based on OPMs.
• To evaluate the performance of an OPM-based MEG system.
• To compare the OPM-based MEG system with a commercial SQUID-based MEG system.

Main Methods:

• Development of an OPM-based MEG system with 20 channels conforming to the scalp.
• Conducting MEG experiments on three subjects, measuring somatosensory evoked magnetic fields (SEF) and auditory evoked magnetic fields (AEF).
• Cross-validation of system robustness by comparing equivalent current dipole (ECD) locations between OPM-based and SQUID-based MEG systems.

Main Results:

• The OPM-based MEG system achieved sub-centimeter accuracy for both SEF and AEF responses in all subjects.
• Robustness was validated through cross-comparison with a commercial SQUID-based MEG system.
• The proximity of OPM channels (12 mm) to the scalp was noted.

Conclusions:

• The OPM-based MEG system demonstrates high accuracy for brain activity measurement.
• Future OPM-based MEG systems are anticipated to offer enhanced spatial resolution compared to traditional SQUID systems.
• OPM technology holds significant potential for advancing non-invasive functional brain imaging.