Towards the Optimization of the Preclinical PET Systems for Minimum Detectable Activity Performance

Traditional figures of merit that were used to evaluate a positron emission tomography (PET) system do not directly reflect the detection of the system. In this work, an analytical minimum detectable activity (MDA) evaluation method was developed and validated with phantom experiments and visual assessments. The analytical method was also applied to evaluate and compare between the two preclinical PET systems at the Crump imaging facility: the Focus220 and the Inveon, under different imaging conditions.;Several possible MDA improvement methods were proposed and discussed, which includes the evaluation of different reconstruction algorithms, accurate detector response modeling, and developing new systems using different scintillation crystals and system geometries.;Based on a simulation study of a virtual PET system, an unconventional low-cost, bench-top system named PETbox were proposed and developed. The system is dedicated to pharmacokinetic and pharmacodynamic mouse studies, and provides an integrated solution for preclinical animal imaging. Monte Carlo based simulations were performed for system design and optimization. Planar detectors were fabricated and their performance was characterized. ML-EM reconstruction and normalization algorithms were developed. Performance of the prototype PETbox system, including system sensitivity, spatial resolution, count rate capability, preliminary quantification and in-vivo static and dynamic mouse studies were evaluated. The results demonstrated the potential of this new tomography for small-animal imaging with enough performance for the targeted application and comparable detection limit to conventional systems.