Speaker
Description
Abstract:
The Jagiellonian Positron Emission Tomograph (J-PET) collaboration is developing a Total-Body PET system based on plastic scintillators, with silicon photomultipliers (SiPM) located at the strip ends, and gamma detection is achieved through Compton scattering [1]. Results presented at the PSMR 2024 conference included time-difference measurements for plastic scintillators of various lengths in order to determine an optimal detector configuration for a large axial-field-of-view (AFOV) system. Those results motivated the initial concept of constructing the Total-Body J-PET scanner using seven detector rings composed of 33 cm long scintillator modules. The main aim of the J-PET collaboration is to build a cost-effective total-body PET system that can be used for different types of studies, including two-gamma imaging [2], positronium imaging [3], and photon polarization studies [4].
In this study, we report on detector characterization studies leading to the definitive design of the Total-Body J-PET (TB-J-PET) scanner, together with a simulation-based performance evaluation for two-gamma and three-gamma imaging. Experimental measurements were performed using plastic scintillator strips read out by two types of silicon photomultipliers produced by Hamamatsu and Onsemi, together with a collimated beam of 511 keV photons from a Na-22 isotope source. Based on the experimental results, Hamamatsu SiPMs were selected due to their superior performance. With additional experiments, we obtained that by optimizing the operating voltage of the detectors, scintillators with lengths of 33 cm and 60 cm can achieve comparable timing performance. These findings enabled a redesign of the detector geometry and reduced the construction cost.
The definitive design of the TB-J-PET configuration consists of five detection rings with a total AFOV of 254 cm. Two short rings are composed of 33 cm long modules and are intended for the upper-body region, while three long rings are built from 60 cm modules, allowing a reduction in the total number of detector modules while maintaining detector performance. Each ring consists of 24 detector modules, and each module comprises three detection layers.
Simulations were conducted using GATE to evaluate the performance of the TB-J-PET scanner. The studies included both 2-gamma events and 3-gamma events originating from ortho-positronium decays. Dedicated event selection criteria and reconstruction algorithms were implemented within the J-PET Framework to process the simulated data and reconstruct interaction positions. Key performance parameters, such as sensitivity, scatter fraction, and spatial resolution, were evaluated for the TB-J-PET scanner. The simulation results indicate the possibility of the TB-J-PET to perform high-sensitivity 2-gamma and 3-gamma imaging studies.
Acknowledgements:
We acknowledge support from NCN (grants 2021/42/A/ST2/00423, 2021/43/B/ST2/02150,
2022/47/I/NZ7/03112), MNiSW (IAL/SP/596235/2023 and SPUB/SP/627733/2025), SciMat and qLife Priority Research Areas, ERC Advanced Grant POSITRONIUM no. 101199807, and PLGrid infrastructure (PLG/2024/017688, PLG/2025/018762).
Reference:
[1]. P. Moskal et al., PET Clinics, vol. 15, no. 4, pp. 439-452, 2020.
[2]. M. Das et al., Bio-Algorithms and Med-Systems, vol. 20, no. 1, pp. 101-110, 2024.
[3]. P. Moskal et al., Sci Adv, vol. 10, no. 37, pp. eadp2840, 2024.
[4]. P. Moskal et al., Sci Adv, vol. 11, no. 18, pp. eads3046, 2025.
| Track | TBPET |
|---|---|
| Presentation type | Oral |