Evaluation of realistic layouts for next generation on-scalp MEG: spatial information density maps
Journal article, 2017

While commercial magnetoencephalography (MEG) systems are the functional neuroimaging stateof- the-art in terms of spatio-temporal resolution, MEG sensors have not changed significantly since the 1990s. Interest in newer sensors that operate at less extreme temperatures, e.g., high critical temperature (high-Tc) SQUIDs, optically-pumped magnetometers, etc., is growing because they enable significant reductions in head-to-sensor standoff (on-scalp MEG). Various metrics quantify the advantages of on-scalp MEG, but a single straightforward one is lacking. Previous works have furthermore been limited to arbitrary and/or unrealistic sensor layouts. We introduce spatial information density (SID) maps for quantitative and qualitative evaluations of sensor arrays. SID-maps present the spatial distribution of information a sensor array extracts from a source space while accounting for relevant source and sensor parameters. We use it in a systematic comparison of three practical on-scalp MEG sensor array layouts (based on high-Tc SQUIDs) and the standard Elekta Neuromag TRIUX magnetometer array. Results strengthen the case for on-scalp and specifically high-Tc SQUID-based MEG while providing a path for the practical design of future MEG systems. SID-maps are furthermore general to arbitrary magnetic sensor technologies and source spaces and can thus be used for design and evaluation of sensor arrays for magnetocardiography, magnetic particle imaging, etc.

Resolution

Surface-Based Analysis

Multichannel Atomic Magnetometer

Magnetoencephalography

Biomagnetic

Brain

EEG Data

Measurements

Magnetic-Fields

Liquid-Nitrogen

Author

B. Riaz

Sahlgrenska Academy

Christoph Pfeiffer

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Justin Schneiderman

Sahlgrenska Academy

Scientific Reports

2045-2322 (ISSN)

Vol. 7 1 Article no 6974 - 6974

Subject Categories

Medical Engineering

DOI

10.1038/s41598-017-07046-6

More information

Latest update

3/23/2018