  Background: Total-Body imaging offers high sensitivity, single-bed position,
and low dose, but high construction costs limit worldwide utilization. This
study compares existing and developing tomographs using plastic scintillators
via simulations to propose a cost-efficient Total-Body PET scanner.
  Methods: Simulations of eight uEXPLORER tomographs with different
scintillator materials, axial field-of-view, and detector configuration, and
eight J-PET scanners with various field-of-view, plastic scintillator
cross-sections, and layers were performed. Biograph Vision was also simulated.
Two types of simulations were conducted with a central source and a
water-filled phantom.
  Results: BGO crystal-based scanners showed the best sensitivity (350 cps/kBq
at the center). Sparse geometry or LYSO crystals reduced sensitivity. J-PET
design showed similar sensitivity to sparse LYSO detectors, with full body
coverage and additional gain for brain imaging.
  Conclusion: The J-PET tomography system using plastic scintillators could be
a cost-efficient alternative for Total-Body PET scanners, overcoming high
construction costs while maintaining sensitivity
