Fast ART Algorithm Based on Simplified Weighting Factor Calculation

Abstract

In the image reconstruction of computed tomography (CT), the algebra reconstruction technique (ART) has many virtues that the analytic reconstruction algorithms don't have. In this paper, a simplified weighting factor calculation method is proposed. All voxels are firstly projected at a scanning angle, and the voxels and the rays are classified on the basis of the distance between the voxel's projection and the ray's projection. For the reason that the voxel mainly contributes to the projection value of the nearest ray, the weighting factors of the voxels to the ray's projection value in the same classification is approximately 1. Then the reconstruction equations are obtained at a scanning angle. Finally, based on the proposed simplified weighting factor calculation method, a fast ART algorithm for CT image reconstruction is developed. The simulation results show the validity of the proposed fast ART algorithm.