An Improved Analytical Reconstruction for Gated Cardiac SPECT Based on Intra-Frame Similarity

In a method we proposed before, Karhune-Loeve (KL) transform was used to de-correlate the inter-frame correlation before they are reconstructed. The drawback of this method is that the covariance matrix is estimated based on the assumption that all pixels along the time direction obey the similar time function, while it is not always comply with the situation. In this paper, we propose a potential refinement method for spatio-temporal reconstruction for gated cardiac SPECT. The gated cardiac SPECT frames are grouped into several groups according to their intra-frame similarity. Then the different KL transform strategies are applied to these groups. Experimental computer simulation results show that the approach may obtain better performance than the previous one.