Optimization of Design Parameters of Flat Panel Limited Angle TOF-PET Scanner: a Simulation Study

In positron emission tomography (PET) time-of-flight (TOF) information is used to improve the reconstructed image. By improving the coincidence timing resolution (CTR), the angular covarege requirements are reduced, allowing for new possibilities such as open geometry and the use of flat panel detectors. The latter come with some benefits, like lower material cost, new possibilities for modularity and such a scanner would be more compact compared to a conventional ring scanner. Currently achieved values of CTR aren’t sufficient to enable the performance of flat panel scanners to reach the standard set by currently used state-of-the-art scanners in clinical practice. In order to achieve sufficient CTR for flat panel scanners to become viable, improvements have to be made on every level of the detection chain. With some preliminary results with optimised electronics and photodetectors we expect that in a few years CTR as low as 75 ps could be achieved at the system level. In this work various designs of such flat panel scanners were simulated with image quality phantoms in order to determine their performance using the NEMA standard. The simulations were performed using GATE software and image reconstruction was performed using CASToR.