Optimization of the Light Guide Thickness for a PET Detector Using a Small Number of Photosensors

초록

A detector for positron emission tomography (PET) using a small number of photosensors was designed. A light guide was used to obtain a flood image of the scintillation pixel of the designed detector, where the quality of the obtained flood image varies according to the thickness of the light guide. DETECT2000 simulations were performed to calculate the optimal thickness of the light guide to optimize the quality of the flood image. A Gadolinium Aluminium Gallium Garnet (GAGG) scintillator with a size of 2 mm × 2 mm × 20 mm was configured in a 10 × 10 array, and the photosensor consisted of a silicon photomultiplier in a 3 × 3 array. Light guides were designed with thicknesses from 0.5 mm to 2 mm in 0.5 mm thickness intervals. For quantitative evaluation of the image quality, quantitative values were calculated using the distance between two adjacent scintillation pixel images. The results show that the best flood image was obtained when the detector had a light guide thickness of 1.5 mm. When the PET system was configured using the detector with the optimized light guide thickness presented in this study, the signal processing circuit could be simplified using a small number of photosensors. © 2021 The Korean Physical Society. All rights reserved.

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