Pilot Results of Detectors Enhancing TOF and DOI Capabilities, Suitable for TB-PET

This work presents a conceptual design for a Total Body (TB) PET scanner. Although, we show some experimental data obtained with a preliminary detector block configuration, the main focus in this contribution is about system results based on Monte Carlo simulations. The detector blocks are based on an array of semi-monolithic LYSO crystals (slabs). Such slab configuration enhances the Coincidence Time Resolution (CTR) in comparison with monolithic blocks and, moreover, allows one to estimate the impact Depth of Interaction (DOI).In this work, spatial resolution, sensitivity and NECR values were simulated according to the NEMA NU 2 2018 protocol, and compared with other scanners. The parameters used during the simulations are based on experimental tests. In particular, we have experimentally achieved a CTR of 280 ps FWHM and DOI accuracy of 3 mm. To illustrate the system performance, a Derenzo-like phantom has been simulated and reconstructed using an MLEM algorithm. The smallest rods, with 4.8 mm diameter, can be resolved for voxel dimensions of 2 mm. Although comparable results with other commercially available scanners (15 – 25 cm axial length) are found, this system exhibits the unique combination of high TOF and DOI capabilities.