Evaluation of the computer artifacts generated in SPECT reconstruction

Reconstructed images in single-photon emission computer tomography (SPECT) always differ in some way from the original unavailable objects. Many different factors affect such integrity (i.e. collimation, sampling, filtering, scattering, attenuation, etc.). A new approach to selecting the artifacts generated by a computer program is presented. Simulated SPECT projection data were made up in order to detect only the degradations in reconstructed slices due to specific computer implementation of filtered backprojection algorithms in the IDRA system. Some calculations on picture characteristics are described, showing in a qualitative manner the difference, that is the error, between the original model and the computed model. The results can provide a valid guide for better programming. In addition, a new image correction method is proposed. (Auth.)