A proton simulator for testing implementations of proton CT reconstruction algorithms on GPGPU clusters

Proton computed tomography (pCT) is an image modality that will improve treatment planning for patients receiving proton radiation therapy compared with the current treatment techniques, which are based on X-ray CT. Reconstruction of a pCT image requires solving a large and sparse system of linear equations, which should be accomplished within a few minutes in order to be clinically practical. Analyzing the efficiency of potentially clinical reconstruction implementations requires multiple quality pCT data sets. The purpose of this paper is to describe the simulator that was developed to generate realistic pCT data sets to be used in testing the efficiency of reconstruction algorithms, in particular string-averaging and block-iterative projection algorithms using sparse matrix formats on General Purpose Graphics Processing Units (GPGPU)s.