Development of a compact scintillator-based high-resolution Compton camera for molecular imaging

The Compton camera, which shows gamma-ray distribution utilizing the kinematics of Compton scattering, is a promising detector capable of imaging across a wide range of energy. In this study, we aim to construct a small-animal molecular imaging system in a wide energy range by using the Compton camera. We developed a compact medical Compton camera based on a Ce-doped Gd3Al2Ga3O12 (Ce:GAGG) scintillator and multi-pixel photon counter (MPPC). A basic performance confirmed that for 662 keV, the typical energy resolution was 7.4 % (FWHM) and the angular resolution was 4.5 degrees (FWHM). We then used the medical Compton camera to conduct imaging experiments based on a 3-D imaging reconstruction algorithm using the multi-angle data acquisition method. The result confirmed that for a Cs-137 point source at a distance of 4 cm, the image had a spatial resolution of 3.1 mm (FWHM). Furthermore, we succeeded in producing 3-D multi-color image of different simultaneous energy sources (Na-22 [511 keV], Cs-137 [662 keV], and Mn-54 [834 key]). (C) 2016 Elsevier B.V. All rights reserved.