UPMC MEG Brain Mapping Center

The Neuromag® is a state-of-the-art neuromagnetic recording system capable of non-invasively recording magnetic fields produced by neuronal activity occurring within the brain. This observed data is called the magnetoencephalogram (MEG) and is analogous to the electroencephalogram (EEG) but represents the magnetic fields produced by ion flow associated with neuronal activity rather than the electric potentials measured in the EEG.

This system is designed to:

  1. Enhance pre-surgical planning by non-invasively localizing eloquent areas within the brain,
  2. Enhance localization of seizure foci by mapping sources of spiking activity, and
  3. Assess distributions of brain activity related to cognitive function.

Magnetic fields are found whenever there is charge flow (current), whether in a wire or neuronal tissue. The orientation of the magnetic field is governed by the right hand rule which essentially constrains the MEG system to sensing magnetic fields produced by groups of neurons located tangentially to the cortical surface.

The magnetic field passes unaffected through brain tissues and the skull, so it can be recorded outside the head by the Neuromag system.

What MEG Offers

  • A direct measure of brain function. Other brain functional imaging techniques such as fMRI, PET and SPECT are secondary measures of brain function reflecting brain metabolism.
  • A very high temporal resolution device. Events with time scales on the order of msecs can be resolved, differentiating MEG from fMRI, PET and SPECT, which have much longer time scales.
  • Excellent spatial resolution and accuracy. Sources can be localized with an accuracy of millimeters.
  • Completely non-invasive. Injection of isotopes or exposure to X-rays or magnetic fields is not required. Children and infants can be studied and repeated tests done.