Development of a small animal SPECT imager with LYSO scintillator arrays and PSPMTs

We describe a small animal SPECT imager based on scintillation crystal arrays and position sensitive photomultiplier tube (PSPMT). This SPECT detector consists of a cerium doped lutetium-yttrium oxyorthosilicate (LYSO) scintillation crystal (22 × 22 pixel array, 2 mm × 2 mm × 3 mm pixel size), a H8500c PSPMT (Hamamatsu Photonics Co., Ltd., Shizuoka Prefecture, Japan), and a parallel hole collimator (Nuclear Fields Pty. Ltd, St. Marys, Australia). The detector design, electronic setup and image correction method are presented. Conical phantom study and animal experiment (BALB/C male nude mice, 16 week, 20g) were performed for the uniformity correction evaluation and imaging performance test respectively. The preliminary results demonstrate that this SPECT imager can achieve the small animal whole body imaging effectively and thus be one of the modalities of our future multimodality imaging system. The feasibility that LYSO crystal can substitute NaI(TI) for SPECT imager development is also validated..