Reconstruction for proton computed tomography: a Monte Carlo study

Advantages of proton computed tomography (pCT) have been recognized in the past. However, the quality of a pCT image may be limited due to the stochastic nature of the proton path inside the object. In this work, we report a preliminary study on reconstruction of pCT image with improved path estimation. A set of Monte Carlo simulations was carried out with the GEANT4 program, and reconstructed by filtered backprojection method. Simulations with different density contrast settings were compared, and spatial resolution around 0.5 mm for the highest contrast phantom was achieved, which is comparable to that of X-ray CT image. Further improvement by utilizing the statistical properties of proton transport is expected and is under progress.