Modelling Of Scatter In The System Matrix For 3d Pet Image Reconstruction: A Comparative Study

Compton scattering in positron emission tomography (PET) is a major image degrading effect. In this work, an analytical model for Compton scatter is included in the system matrix of two iterative image reconstruction techniques, maximum likelihood expectation maximization (MLEM) and origin ensemble (OE); their performance with respect to conventional MLEM and MLEM with analytic single scatter simulation (SSS) based scatter correction is validated according to the NEMA NU 2-2007 protocol. Background variability is reduced by 9.4% on average compared to MLEM with SSS. Contrast recovery coefficients (CRCs) are improved for larger sources.