Design study for the ClearPET/XPAD small animal PET/CT scanner

We present a small animal PET/CT scanner design based on the ClearPET high resolution PET scanner and the XPAD3 hybrid pixel X-ray detector developed at CPPM. The design study of the configuration and functionality of the combined system is discussed. Using the GATE Monte Carlo simulation platform, the complete system is being investigated for achieving a fully integrated high performance PET/CT scanner. For the new design, we rearrange the LSO/LuYAP phoswich detector modules of the ClearPET demonstrator on its rotating gantry, eliminating the existing axial gaps between the rings of ClearPET modules and increasing its sensitivity by 71%. The functionality for simultaneous scans has been verified experimentally using CT and PET components in one setup. These measurements showed that an additional 500 mum thick brass shielding of the ClearPET detector modules is sufficient to prevent saturation of the PET detectors by low energy scattered X-ray photons.