Design and performance evaluation of partial geometry configurations of total-body PET: A Monte Carlo study

Introduction: This study proposes various designs of partial-ring geometry total-body positron emission tomography (PET) scanners which maintain an extended axial field of view (AFOV) while remaining cost-effective, without sacrificing image quality.Methods: The total-body uEXPLORER PET scanner was simulated using the GATE Monte Carlo code.  Partial-ring PET configurations were simulated, reducing the number of detectors by ۲۵% in both the transaxial and axial directions. The sensitivity, noise equivalent count rate (NECR), and image quality of the partial-ring configurations were compared to those of the full-ring configuration.Results: The system sensitivity of partial-ring designs was ۰.۶۱ and ۰.۷۷ times that of the full-ring detector PET for detector reduction in the axial and transaxial directions, respectively. Notably, despite the higher sensitivity, the ۱۰ mm sphere could not be detected in the transaxial reduction mode. When considering all spheres except the ۱۰ mm one, the mean relative error of contrast recovery (CR) for the same time duration was ۲% for detector reduction in the axial direction, whereas it increased to ۹% for reduction in the transaxial direction.Conclusion: The results show that reducing the number of detectors in total-body PET scanners can significantly lower manufacturing costs associated with long AFOV PET systems. Although the reduced detector configuration resulted in lower sensitivity, the image quality of the NEMA phantom was found to be superior in the axial reduction mode compared to the transaxial reduction mode. Additionally, the image quality exhibited only a slight difference from that of the full-ring scanner.

Keywords:

Partial configurations , uEXPLORER PET , GATE simulator , NEMA IQ phantom