Detector response modeling for β+-γ emitter imaging of the whole gamma imager

The whole gamma imaging (WGI) is our concept combining positron emission tomography (PET) and Compton imaging to utilize various radionuclides for imaging. The WGI is realized by inserting a scatterer ring into a PET detector ring so that the PET detector ring functions as an absorber detector. The β+-γ emitter imaging, which we also call 3-gamma imaging, is one of applications for the WGI. A +- emitter such as 44Sc emits a positron and a single gamma ray at almost the same time, resulting in emission of three gamma rays. Detecting the annihilation photons by the PET detector ring and the single gamma ray by the Compton imaging manner, we can identify the radionuclide position at the cross section of the line-of-response (LOR) and the Compton cone surface. In this study, we proposed a detector function model necessary for the 3-gamma imaging. We used the model to generate back projection image of a β+-γ emitter acquired by the first WGI prototype developed for a proof-of-concept. As a result, the image generated by the proposed model was clearer than that by LOR information only.第5回放医研・ソウル大ワークショッ