Ultracompact Compton camera for innovative gamma-ray imaging

• DOI: 10.1016/j.nima.2017.09.048
• Publication Date: 2017-09-28T06:46:20Z
• Authors: J. Kataoka; A. Kishimoto; T. Taya; S. Mochizuki; L. Tagawa; A. Koide; K. Sueoka; H. Morita; T. Maruhashi; K. Fujieda; T. Kurihara; M. Arimoto; H. Okochi; N. Katsumi; S. Kinno; K. Matsunaga; H. Ikeda; E. Shimosegawa; J. Hatazawa; S. Ohsuka; T. Toshito; M. Kimura; Y. Nagao; M. Yamaguchi; K. Kurita; N. Kawachi
• Keywords: Gamma camera

Abstract A multipixel photon counter (MPPC) features excellent photon-counting capability as a radiation detector. In particular, a two-plane Compton camera consisting of Ce:GAGG scintillators coupled with MPPC arrays has significant application potential owing to its compact size and low weight. For example, the camera can be easily mounted on a commercial drone to identify radiation hot spots from the sky. In Fukushima, we demonstrated that a 137 Cs distribution within a 100 m diameter can be mapped correctly within a couple of tens of minutes. The advanced use of the Compton camera is also anticipated in the field of proton therapy. We evaluated an image of 511 keV annihilation gamma-rays emitted from a PMMA phantom irradiated by 200 MeV protons to mimic an in-beam monitor for proton therapy. Finally, we developed an ultracompact Compton camera (weight = 580 g), for 3-D multicolor molecular imaging. In order to demonstrate the performance capabilities of the device, 131 I (365 keV) , 85 SrCl 2 (514 keV), and 65 ZnCl 2 (1116 keV) were injected into a living mouse and the data were taken from 12 angles with a total acquisition time of 2 h. We confirmed that all tracers had accumulated on the target organs of the thyroid, bone, and liver, and that the obtained 3-D image was quantitatively correct with an accuracy of ± 20%.