Resolution enhancement of biomagnetic images using the method of alternating protections

Resolution of biomagnetic images using the technique of alternating projections is proposed. The image reconstruction procedure is divided into two steps. First, the biomagnetic inverse problem is solved by using 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 linelike elements and involves finding such 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 conductors shaped in the form of the letters, U, W, and B and of the ´at´ symbol, and all of linelike thickness. Restored images closely resemble the original shape of the conductors.