Magnetic Source Imgaging

Magnetic Source Imaging {MSI) is a relatively new diagnostic imaging technique using simple passive detection of the brain's magnetic activity to provide objective functional information. MSI provides precise localization of brain function independent of the injection of radioactive isotopes, scalp electrodes, or radio-frequency input. The electrical activity of the brain produces weak magnetic fields from neuronal currents. These magnetic fields can be recorded using sensitive magnetic detectors over the intact surface of the skull. The spatial distribution of magnetic field intensities can be plotted geographically and utilized to calculate three-dimensional localizations of focal sources of the magnetic activity which can be super-imposed on standard MR or CT images. The resulting montage of information is collectively referred to as a magnetic source image (MSI).