Journal Article Poisson noise SPECT tomography Acquisition geometry Analytic image reconstruction Analytical reconstruction Artifacts Attenuated Radon transform Computed tomography Dynamic imaging Filtered backprojection Filtered backprojection algorithm MAP objective function MRI Real time imaging analytic image reconstruction analytical algorithm angular sampling computed tomography edge-preserving filters expectation maximization (EM) exponential Radon transform filtered backprojection (FBP) algorithm filtered backprojection algorithm image reconstruction iterative algorithm iterative image reconstruction iterative reconstruction maximum likelihood (ML)