Advanced PET detector with function of Compton camera for simultaneous multi-nuclide imaging

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K20723
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 90130:Medical systems-related
• Research Institution: National Institutes for Quantum and Radiological Science and Technology
• Principal Investigator: Takyu Sodai 国立研究開発法人量子科学技術研究開発機構, 放射線医学総合研究所 先進核医学基盤研究部, 博士研究員(任常) (60796473)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 放射線検出器 / コンプトンカメラ / PET

Outline of Final Research Achievements

Positron emission tomography (PET), which is a nuclear medicine imaging modality, can only use 511 keV annihilation photons for imaging, and thus cannot visualize multiple functions of a living body simultaneously. In this study, we developed a PET detector with a function of Compton camera that can image a wide range of gamma ray energies simultaneously. A two-layered scatterer detector consisting of GSO scintillators and a multi-pixel photon counter (MPPC) array module was developed, and a PET detector developed in another project in our laboratory was used as an absorber detector to construct a PET detector with Compton camera function. Simultaneous imaging of point sources of Na-22 (511 keV and 1275 keV) and Cs-137 (662 keV) was performed, and each source could be visualized separately.

Free Research Field

医用放射線工学

Academic Significance and Societal Importance of the Research Achievements

PETは他の核医学診断装置であるSPECT（単一光子放射断層撮影）に比べ空間分解能や画像の定量性に優れているが、複数の分子プローブを同時に使用することはできず、複数の因子が複雑に関与する疾患等の発生要因を明らかにすることはできない。そこで、様々なエネルギーのガンマ線を可視化できるコンプトンカメラの技術に着目した。PET検出器にコンプトンカメラの原理を応用すれば、PETとしての空間分解能・感度を維持しながら、複数核種の同時撮像が可能となり、核医学診断の分野において大きなイノベーションになると期待する。