Ultra-high-resolution depth-encoding small animal PET detectors: using GAGG and LYSO crystal arrays
Ultra-high-resolution depth-encoding small animal PET detectors: using GAGG and LYSO crystal arrays
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DOI：
10.1002/mp.15606
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Yongfeng Yang
中科院分区：
文献类型：
--
作者：
Ming niu;Zheng Liu;Zhonghua Kuang;Xiaohui Wang;Ning Ren;Ziru Sang;San Wu;Longhan Cong;Tao Sun;Zhanli Hu;Yongfeng Yang
Purpose: Small animal PET scanners are widely used in current biomedical research. The aim of this work is to develop high efficiency and ultra-high resolution detectors that can be used to develop a small animal PET scanner with high sensitivity and spatial resolution approaching the physical limit..Methods: 4 crystal arrays were fabricated and measured in this work. Crystal arrays 1 and 2 consist of 38×38 GAGG and LYSO crystals 0.4×0.4×20 mm3 in size. Crystal array 3 consists of 16×16 GAGG crystals 0.3×0.3×20 mm3 in size, and crystal array 4 consists of 24×24 LYSO crystals 0.3×0.3×20 mm3 in size. The crystal arrays are dual-ended read out by using 8×8 SiPM arrays of 2×2 mm2 pixel area. The SiPM array is read out using a signal multiplexing circuit to convert the 64 energy signals to 4 position-encoding energy signals. The performances of the 4 detectors in terms of flood histogram, energy resolution, depth of interaction resolution and timing resolution are measured. .Results: The GAGG detectors provide better flood histograms, ~30% higher photopeak amplitude, ~20% higher energy resolution, ~12% worse DOI resolution and ~15% worse timing resolution as compared to LYSO detectors of the same crystal size. These 4 detectors provide DOI resolutions of <2 mm, energy resolutions of <22% and timing resolutions of <1.6 ns. All crystals with sizes of 0.4×0.4×20 mm3 and 0.3×0.3×20 mm3 can be clearly resolved if the crystal array is 1 mm smaller in the four sides than the SiPM array. .Conclusions: High DOI resolution PET detectors were developed by using both GAGG and LYSO arrays with crystal sizes of 0.3 and 0.4 mm, and a length of 20 mm. The detectors can be used in the future to develop small animal PET scanners, especially dedicated mouse imaging PET scanners, which will simultaneously achieve high sensitivity and ultra-high spatial resolution.
