Characteristics

Spatial Resolution
≥2 cm
Temporal Resolution
~1 ms
Maturity
Established
Invasiveness
Non-invasive

Uses magnetic field detection, no contact with patient required

Summary
Magnetoencephalography — detects magnetic fields from neuronal currents, typically with SQUID-based sensors
Tags
Magnetic
Electromagnetic
Effects Involved
NEURAL-ELECTRIC

Details

Magnetoencephalography (MEG) measures the magnetic fields generated by neuronal currents outside the head. Conventional whole-head systems use superconducting quantum interference devices (SQUIDs), which require cryogenic cooling, while newer optically pumped magnetometer (OPM) systems are cryogen-free.

MEG offers millisecond-scale temporal resolution and generally better source localization than EEG because magnetic fields are less distorted by the skull and scalp than electric potentials. Source-localized resolution can reach the millimetre range in favourable conditions, although sensor-level localization is coarser.

MEG is widely used in research and in clinical settings such as presurgical epilepsy mapping.

MEG

Neural current
Magnetic field
SQUID sensor
Liquid helium
Magnetic shielding

Literature Review

TitleSpatial Res.Temporal Res.SubjectsSummary

Magnetoencephalography with optically pumped magnetometers (OPM-MEG): the next generation of functional neuroimaging (2022)

Reviews conventional SQUID MEG and newer OPM-MEG systems, emphasizing that OPM sensors avoid cryogenics while improving flexibility and potentially spatial resolution.

Improved vs SQUID MEGMillisecond-scaleHumansReviews conventional SQUID MEG and newer OPM-MEG systems, emphasizing that OPM sensors avoid cryogenics while improving flexibility and potentially spatial resolution.