Cone beam cover method: An approach to performing backprojection in Katsevich's exact algorithm for spiral cone beam CT

Abstract

The conventional implementation of Katsevich's inversion formula involves the computation of PI segment. This is done by solving a nonlinear equation with a numerical algorithm such as Newton's method. In this study, we develop an implementation of Katsevich's inversion formula without computing PI segment. Our implementation involves a new concept, cone beam cover, which is closely related to PI segment and Tam-Danielsson window. Unlike the implementation based on PI segment, the algorithm complexity of our implementation can be estimated with several important imaging parameters. This result may be instructive for practical applications to choose scanning parameters and reduce the algorithm complexity. The proposed implementation is validated with satisfactory numerical experiments.