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内容記述 |
For small animal positron emission tomography (PET), spatial resolution is the most important factor to visualize mouse brain function with high quantification accuracy. However, for the last two decades, the spatial resolution of PET has been limited to over 0.5 mm due to unoptimized detector designs. Here, we propose a mouse brain dedicated PET scanner with staggered 3-layer depth-of-interaction (DOI) detectors to achieve sub-0.5 mm resolution. The effects of crystal pitch (1.0, 0.8, and 0.6 mm) and crystal layer design (4+4+7 mm, 3+3+5 mm) on the spatial resolution were investigated using GATE. Based on the GATE simulation results, we developed a prototype mouse brain PET scanner. The PET has an inner diameter of 48 mm and axial coverage of 23.4 mm. The PET scanner has two rings, each of which has 16 DOI detectors. Each DOI detector has 3-layer LYSO crystal with a crystal pitch of 0.8 mm. To evaluate spatial resolution and imaging performance, a 22Na point source and resolution phantom (rod diameter: 0.45, 0.5, 0.55, 0.75, 0.8, and 0.85 mm) were used respectively. The smallest rod diameter of 0.45 mm was clearly identified with both GATE simulations and experiments. The spatial resolution results obtained with GATE simulations showed good agreement with those of experimental results. In conclusion, GATE is a useful Monte Carlo simulation toolkit to design ultrahigh resolution PET scanners. |
