Method of image reconstruction in limited-angle imaging

摘要

To achieve a large reduction in the amount of computer time in limited-angle computerized tomography, the reconstructed image is decomposed into two partial images reconstructed from available scan data and missing scan data. Because the former is unchanged during the interative image reconstruction procedure, it is reconstructed from the measured projections only once at the beginning of the iterations and used repeatedly. The composite image formed by summing the two partial images is corrected by the a priori information about the object. The improved partial image due to missing projections is calculated and again summed with the partial image due to measured projections and corrected. These steps are iteratively repeated until a test for convergence yields a final image. A limited-angle x-ray CT system utilizes the projection space version of the iterative transform algorithm.