The performance evaluation of the newly developed scintillator materials in the HiReSPECT camera: Monte Carlo simulation study

Abstract: In the gamma camera, an appropriate design of the detector affects the performance of the imaging system. Detectors are desired with high intrinsic efficiency, good, and intrinsic spatial energy resolutions. In the medical imaging, simulations are primarily used for the design and optimization of the new and existing imaging devices. Among the available Monte Carlo codes for simulations in emission tomography, GATE is a reliable tool for simulating PET and SPECT scans. We simulated a small animal SPECT equipped with a pixelated CsI (Na) crystal and hexagonal parallel-hole collimator by using the GATE code. In the following, the CsI (Na) crystal was replaced with LYSO, LaBr3(Ce), CeCL3(Ce), YSO and YAP(Ce) scintillators to evaluate the effect of these newly developed scintillators on the performance of the HiReSPECT camera. The simulated energy resolutions of LYSO and LaBr3 at 140 keV energy were 5.21 and 3.38% respectively while the experimental and simulated energy resolutions of the HiReSPECT were 19.15 and 18.26%. Also, LYSO and LaBr3 provided 11.71 and 7.03% improvement in the spatial resolution compared to the HiReSPECT. The sensitivities of LYSO, LaBr3(Ce), CeCl3, YSO, YAP and NaI (Tl) were calculated 1.906, 1.29, 1.12, 1.22, 0.56 and 0.8 cps/μCi on the collimator surface, respectively. The recently developed scintillation crystals have the potential to be chosen as the detectors in the animal SPECT scanners owing to their high sensitivity, better energy, and spatial resolutions.

کلیدواژه ها:

Small Animal SPECT ، Gamma Camera ، GATE ، scintillator ، HiReSPECT