A MATHEMATICAL METHOD OF FAN-BEAM CT IMAGE RECONSTRUCTION BASED ON THE SYMMETRY ENHANCEMENT GEOMETRY

In this paper a mathematical method of fan-beam CT image reconstruction is introduced on the basis of the symmetry enhancement geometry. This geometry consists of two components: the even symmetry between the sampling points in the reconstruction coordinate system and all the central rays of projections, and the enhanced eightfold symmetry among these sampling points. It is shown from computer simulation that the accuracy requirement can be satisfactorily reached under some available parameters. In contrast with other methods of the fan-beam CT image reconstruction, this algorithm makes the best use of eightfold symmetry, and is convenient for parallel processing with hardware. We believe that it is economically feasible for parallel processing, and can lead to an order of magnitude reduction in the reconstruction time.