Exploration of simultaneous dual-isotope imaging with multiphoton modular J-PET scanner

Abstract

The modular J-PET scanner, comprising 24 compact and versatile modules, each consisting of 13 plastic strips with four SiPM detectors at the ends, represents a powerful tool for clinical applications in nuclear medical imaging. This study presents preliminary results from the exploration of simultaneous dual-isotope imaging using the modular J-PET system. Our approach involved two isotopes: <sup>68</sup>Ge, characterized by a ringlike shape, and <sup>22</sup>Na, exhibiting a point-like shape. The imaging was based on double-coincidence and triple-coincidence events. In the double coincidence case, both isotopes contributed comparably, whereas in the triple coincidence case <sup>22</sup>Na dominated due to the prompt gamma being emitted with 100% of positron emissions, unlike <sup>68</sup>Ga, where the prompt gamma was emitted in only 1.3% of cases after positron emission. In this work we present direct 2γ images determined for two-signal events and images for three-signal events, with two signals from annihilation photons and one from a prompt gamma. These results showcase the preliminary findings from simultaneous dual-isotope imaging of <sup>68</sup>Ga and <sup>22</sup>Na isotopes using the modular J-PET scanner, which will be presented and discussed.