Performance demonstration of a hybrid Compton camera with an active pinhole for wide-band X-ray and gamma-ray imaging

Akihisa Omata, Jun Kataoka, Kazuya Fujieda, Shogo Sato, Eri Kuriyama, Hiroki Kato, Atsushi Toyoshima, Takahiro Teramoto, Kazuhiro Ooe, Yuwei Liu, Keiko Matsunaga, Takashi Kamiya, Tadashi Watabe, Eku Shimosegawa, Jun Hatazawa

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

X-ray and gamma-ray imaging are technologies with several applications in nuclear medicine, homeland security, and high-energy astrophysics. However, it is generally difficult to realize simultaneous wide-band imaging ranging from a few tens of keV to MeV because different interactions between photons and the detector material occur, depending on the photon energies. For instance, photoabsorption occurs below 100 keV, whereas Compton scattering dominates above a few hundreds of keV. Moreover, radioactive sources generally emit both X-ray and gamma-ray photons. In this study, we develop a “hybrid” Compton camera that can simultaneously achieve X-ray and gamma-ray imaging by combining features of “Compton” and “pinhole” cameras in a single detector system. Similar to conventional Compton cameras, the detector consists of two layers of scintillator arrays with the forward layer acting as a scatterer for high-energy photons (> 200 keV) and an active pinhole for low-energy photons (< 200 keV). The experimental results on the performance of the hybrid camera were consistent with those from the Geant4 simulation. We simultaneously imaged 241Am (60 keV) and 137Cs (662 keV) in the same field of view, achieving an angular resolution of 10 (FWHM) for both sources. In addition, imaging of 211At was conducted for the application in future nuclear medicine, particularly radionuclide therapy. The initial demonstrative images of the 211At phantom were reconstructed using the pinhole mode (using 79 keV) and Compton mode (using 570 keV), exhibiting significant similarities in source-position localization. We also verified that a mouse injected with 1 MBq of 211At can be imaged via pinhole-mode measurement in an hour.

Original languageEnglish
Article number14064
JournalScientific reports
Volume10
Issue number1
DOIs
Publication statusPublished - 2020 Dec 1

ASJC Scopus subject areas

  • General

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