ABSTRACT
This chapter considers linear, nonshift invariant reconstruction applied to single photon emission computed tomography. There are two broad categories of emission computed tomography — positron emission tomography and a single photon emission computed tomography. In X-ray computed tomography, the goal is to measure the attenuation of the pixels in the cross section. Single photon emission computed tomographic data are collected using a rotating gamma camera. The chapter utilizes the linear system model to understand the data collection process and to develop a heuristic understanding of image reconstruction. It focuses on the iterative solution for image reconstruction. Post-reconstruction correction can be used as part of any approximate algorithm. A post-reconstruction correction can be used at the end to improve the uniformity of the reconstruction for flood sources. The major effect of a post-reconstruction correction is to make the values in a uniform flood source end up uniform.
