Resolution enhancement of biomagnetic images using the method of alternating protections.

Abstract

Resolution of biomagnetic images using the technique of the alternating projections is proposed. Our image reconstruction procedure is divided in two steps. First, the biomagnetic inverse problem is solved by use of the projection theorem to reconstruct an initial image of the current distribution from a given magnetic field profile. Although the current distribution thus obtained has poor resolution, it can resemble the original shape of the current distribution. The second step improves the resolution of the reconstructed image by using the method of alternating projections. The procedure assumes that images can be represented by line like elements and involves finding the line like elements based on the initial image and projecting back onto the original solution space. Simulation studies were performed on a set of parallel conductors and a shape of the conductors in the form of letters, UWB@. All conductors were of line like thickness. Restored images closely resemble the original shape of the conductors.