Neuromagnetic source analysis with a 64-channel SQUID system and MR imaging

Abstract

Describes a high-resolution biomagnetic source localization by using 64 channel SQUID system and MRI. Here, the magnetic source is modeled as a current dipole, and the head is modeled as a conductive sphere. These models make it possible to calculate the magnetic field produced by the impressed current and the volume current. The least squares cost function to specify the dipole parameters is minimized by the improved simplex algorithm. The authors investigate the influence of the correlation and the distance between dipoles by performing a computer simulation. Auditory evoked magnetic sources are localized by utilizing the anatomical MR image. Estimated locations are combined with the 3D MR image to visualize and understand the neural activity.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>