Simulation Study of Compton Camera Design for 3D High-resolution Prompt Gamma Imaging with Low Background Noise

Abstract

In this study, we used the CZT and LYSO to simulate the different Compton cameras because of their high detection efficiency for high-energy photons and the spatial and energy resolution required for high-resolution imaging. Then we investigated the performance of the Compton cameras with different design in terms of prompt gamma detection efficiency, background noise and reconstruction accuracy. The background noises evaluated in our study included the background noise caused by the neutrons induced by proton beam, and the accidental coincidence between annihilation photons, and the multiple scattering in a single layer, as well as back-scattering. The simulation results showed that the proposed design can simultaneously take advantage of the high energy resolution of CZT and the high detection efficiency of LYSO. Compared with the Compton camera composed of a mixture of two materials, it has higher detection efficiency and a smaller proportion of noise events. Besides, by adjusting the weights of the two data in the origin ensemble with resolution recovery iteration, the CZT data with better energy resolution can contribute to a better iteration effect, while the LYSO data keeps the image from being distorted due to the lack of the effective events. Finally, we obtained the 3D reconstruction of prompt gamma with high resolution and low background noise, demonstrating the potential of the proposed Compton camera design.