Development of depth-of-interaction digital PET detector

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K12857
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 90130:Medical systems-related
• Research Institution: National Institutes for Quantum Science and Technology
• Principal Investigator: Yoshida Eiji 国立研究開発法人量子科学技術研究開発機構, 量子医科学研究所 先進核医学基盤研究部, 主幹研究員 (50392246)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: PET / 検出器 / depth-of-interaction / time-of-flight

Outline of Final Research Achievements

To improve PET image quality, depth-of-interaction (DOI) information, which can reduce the parallax error, and time-of-flight (TOF) information, which can enhance the signal-to-noise ratio in a reconstructed image, are key technologies. However, it is difficult to realize and employ both technologies at the same time without degradation of the information obtained. We have developed the 3D digital PET detector that optically couples the four-loop structure, consisting of quadrisected fast LGSO crystals comparable in size to a photo-sensor, to four photo-sensors in close proximity arranged in a windmill shape. In this work, we developed the PET detector using the fast LGSO crystal for the TOF-DOI PET system. The developed detector with 1.45-mm fast LGSO crystals and ESR reflectors provided 10.1% energy resolution, 4.7 mm DOI resolution, and 293 ps CRT.

Free Research Field

核医学

Academic Significance and Societal Importance of the Research Achievements

本検出器は従来困難な課題であったDOIとTOFの両立を1.45 mmという高い空間分解能のシンチレータで達成した。小動物PETにおいてはDOIが、臨床PETにおいてはTOFが重要視されるため、本検出器は様々なPET装置に適用可能である。また、従来の2次元検出器に対して、本検出器の主な変更点は反射材構造のみであり、低コストでの製品化が可能である。