Performance characterization of a prototype Si/CdTe Compton camera

Kawachi, Naoki; Watanabe, Shigeki; Fujimaki, Shu; Ishioka, Noriko; Sato, Takahiro; Kamiya, Tomihiro; Arakawa, Kazuo; Watanabe, Shin*; Takeda, Shinichiro*; Ishikawa, Shinnosuke*; Aono, Hiroyuki*; Takahashi, Tadayuki*; Shimada, Hirofumi*; Yoshida, Yukari*; Yamaguchi, Mitsutaka*; Suzuki, Yoshiyuki*; Sakurai, Hideyuki*; Nakano, Takashi*

The Compton camera is a next-generation in vivo imaging system. In order to achieve accurate Compton imaging, it is necessary to develop technologies that can be used to detect the Compton scattering in the camera and estimate the direction of a incoming -ray produced by a radiation source. These techniques will be different from the methods used in PET and SPECT to detect the -ray with the coincidence of two points and with the physical collimation. We have developed a prototype Compton camera for in vivo imaging by using semiconductor imaging devices, which has been proved to be successful techniques for the an observation of high-energy astrophysical phenomena. In this camera, double-sided Si strip detectors (DSSDs) serve as scatterers and CdTe pixel detectors serve as absorbers. In this paper, we present some images acquired with the Compton camera; we have also acquired images of radioisotopes in a phantom, which reveal certain characteristic distributions of efficiencies and spatial resolutions.