@misc{oai:repo.qst.go.jp:00075716,
 author = {田島, 英朗 and 吉田, 英治 and 奥村, 勇介 and 菅, 幹生 and 河地, 有木 and Kamada, Kei and Parodi, Katia and 山谷, 泰賀 and Hideaki, Tashima and Eiji, Yoshida and Yusuke, Okumura and Mikio, Suga and Naoki, Kawachi and Taiga, Yamaya},
 month = {Apr},
 note = {[Purpose] We have proposed a new concept of whole gamma imaging (WGI), which is a novel combination of PET and Compton imaging, and we have showed by simulation the feasibility of triple-gamma imaging targeting β+-γ emitters, which emit both a positron and a gamma ray almost at the same time. In this study, we developed a proof-of-concept prototype of the WGI and an imaging method for the triple-gamma imaging incorporating resolution modeling.
[Method] We developed a WGI prototype by inserting a scatterer detector ring (20 cm in inner diameter, 20x2 (transverse x axial) detectors each consisted of a 24x24x1 array of 0.9x0.9x6-mm3 GAGG crystals and a 8x8 array of 3-mm multipixel photon counters (MPPCs)) into a PET (absorber) detector ring (66 cm in inner diameter, 40x4 detectors each consisted of a 16x16x4 array of 2.8x2.8x7.5-mm3 Zr-doped GSO crystals and 64-ch photo multiplier tubes). In the triple-gamma imaging, radioactivity source position can be determined as the intersection point between a line-of-response (positron) and a Compton cone (gamma ray) in the field of view. The half-cone angle of the Compton cone is equal to the scatter angle determined by the Klein-Nishina equation using energy information. We derived an equation necessary to determine the intersection point and developed a method to model blurring effect of the cone due to the energy resolution of the detectors. To demonstrate the effectiveness of the triple-gamma imaging, we measured a 22Na point source, which emits a positron and a 1274 keV gamma ray, placed at various positions by using the WGI prototype.
[Results] We compared triple-gamma images generated by back-projection using the proposed model and using only LOR information for the same list-mode data set. The proposed method could generate clearer image.
[Conclusion] We demonstrated that the triple-gamma imaging is possible with the WGI prototype and the proposed method., 第117回日本医学物理学会学術大会},
 title = {Whole Gamma Imaging: demonstration of the β＋-γ coincidence},
 year = {2019}
}