Linear closed-form methods for ideal-sinogram estimation in 2D SPECT

We derived explicit relationships between the ideal sinogram and the sinogram degraded by both attenuation and distance-dependent spatial resolution in 2D SPECT that is described by either a Cauchy or a Gaussian function. Attempts to reduce the statistical variance in the reconstructed image lead to the development of infinite classes of closed-form methods for estimation of the ideal sinogram. These methods were applied in both computer-simulation and real-data studies.