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

The modular J-PET scanner, comprising twenty-four compact and versatile modules, each consisting of thirteen 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 involves two isotopes: $^{68}$Ge, characterized by a ring-like shape, and $^{22}$Na, exhibiting a point-like shape. The imaging is based on the double-coincidence and triple-coincidence events. In the double coincidence case, both isotopes contribute comparably, whereas in the triple coincidence case, $^{22}$Na dominates due to the prompt gamma being emitted with 100% of positron emissions, unlike $^{68}$Ga where the prompt gamma is 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 $^{68}$Ga and $^{22}$Na isotopes using the modular J-PET scanner, which will be presented and discussed.