Development of a high resolution gamma camera system using finely grooved GAGG scintillator

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• 作者：Seiichi Yamamoto^a ; ; Jun Kataoka^b ; Tsubasa Oshima^b ; Yoshimune Ogata^a ; Tadashi Watabe^c ; Hayato Ikeda^c ; Yasukazu Kanai^c ; Jun Hatazawa^c
• 关键词：GAGG ; Grooved ; Gamma camera ; PSPMT ; High resolution
• 刊名：Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
• 出版年：2016
• 出版时间：11 June 2016
• 年：2016
• 卷：821
• 期：Complete
• 页码：28-33
• 全文大小：1530 K

文摘

High resolution gamma cameras require small pixel scintillator blocks with high light output. However, manufacturing a small pixel scintillator block is difficult when the pixel size becomes small. To solve this limitation, we developed a high resolution gamma camera system using a finely grooved Ce-doped Gd₃Al₂Ga₃O₁₂ (GAGG) plate. Our gamma camera׳s detector consists of a 1-mm-thick finely grooved GAGG plate that is optically coupled to a 1-in. position sensitive photomultiplier tube (PSPMT). The grooved GAGG plate has 0.2×0.2 mm pixels with 0.05-mm wide slits (between the pixels) that were manufactured using a dicing saw. We used a Hamamatsu PSPMT with a 1-in. square high quantum efficiency (HQE) PSPMT (R8900-100-C12). The energy resolution for the Co-57 gamma photons (122 keV) was 18.5% FWHM. The intrinsic spatial resolution was estimated to be 0.7-mm FWHM. With a 0.5-mm diameter pinhole collimator mounted to its front, we achieved a high resolution, small field-of-view gamma camera. The system spatial resolution for the Co-57 gamma photons was 1.0-mm FWHM, and the sensitivity was 0.0025%, 10 mm from the collimator surface. The Tc-99m HMDP administered mouse images showed the fine structures of the mouse body׳s parts. Our developed high resolution small pixel GAGG gamma camera is promising for such small animal imaging.