Deconvolution scatter compensation for thallium-201 fan-beam cardiac SPECT

Scatter radiation is a large fraction of the measured projection data in Tl-201 SPECT and has significant effect on the reconstructed images. We investigated both pre- and post-filter implementations of the deconvolution scatter compensation method and several methods of estimating the scatter-to-primary ratio and scatter point response function using the attenuation map. For comparison, we also extended the dual energy window scatter compensation with a method to accurately estimate the k factor used. Both scatter compensation methods were assessed using a thorax phantom and Monte Carlo simulations. Quantitative accuracy of higher than 90% is achieved for both the prefilter implementation of the deconvolution method and the dual energy window method with an accurately determined k factor. Among the two, the deconvolution method has slightly less noise in the reconstructed image