Analytic system matrix resolution modeling in PET: An application to Rb-82 cardiac imaging

An area of growing interest in PET imaging has been that of incorporating increasingly more accurate system matrix elements into the reconstruction task, thus arriving at images of higher quality. This work explores application of an analytic approach which individually models and combines the various resolution degrading phenomenon in PET (inter-crystal scattering, inter-crystal penetration, photon non-collinearity and positron range), and does not require extensive experimental measurements and/or simulations. The approach is able to produce considerable enhancements in image quality. The reconstructed resolution is seen to improve from 5.1mm-7.7mm across the field-of-view (FoV) to ap3.5mm nearly uniformly across the FoV. Furthermore, phantom studies indicate clearly improved images, while similar significant improvements are seen for the particular task of Rb-82 cardiac imaging.