NEC-scaling applied to FORE+OSEM

We evaluate the use of FORE with NEC-scaling 2D OSEM for 3D whole-body PET imaging. We had previously proposed combining 3D imaging with the 2D attenuation weighted (AW) OSEM statistical image reconstruction algorithm by using FORE to reduce statistical noise in clinical whole-body PET imaging. Although attenuation correction is responsible for the major deviation from the Poisson model in whole-body imaging, the other quantitative corrections, and FORE itself, also modify the statistical properties of the rebinned data. To use a more accurate statistical modelling in the reconstruction algorithm, additional factors can be included using the noise equivalent count (NEC) transformation method proposed by Nuyts et al.