Proton computed tomography images with algebraic reconstruction

A prototype of proton Computed Tomography (pCT) system for hadron-therapy has been manufactured and tested in a 175. MeV proton beam with a non-homogeneous phantom designed to simulate high-contrast material. BI-SART reconstruction algorithms have been implemented with GPU parallelism, taking into account of most likely paths of protons in matter. Reconstructed tomography images with density resolutions r.m.s. down to ~1% and spatial resolutions <1. mm, achieved within processing times of ~15' for a 512×512 pixels image prove that this technique will be beneficial if used instead of X-CT in hadron-therapy.