Pre-reconstruction restoration versus post-reconstruction restoration of single photon emission computed tomography images

Restoration of single photon emission computer tomography (SPECT) images may be performed either before reconstruction (pre-reconstruction restoration) or after reconstruction (post-reconstruction restoration) from planar (projection) images. The authors present a comparison of results obtained by these two methods. The filters investigated in this study are the Wiener and power spectrum equalization filters. The filters were applied to SPECT images of a hollow cylinder phantom and a cardiac phantom acquired on a Siemens Rota camera. Quantitative analysis of the results were performed through measurements of contrast ratios and root mean squared errors. The pre-reconstruction restored images show a significant decrease in the root mean squared error and an increase in contrast over the post-reconstruction restored images