Gated cardiac SPECT using different motion models

Gated cardiac SPECT imaging suffers from several degrading factors ranging from limited data counts to motion blur. In this work we investigate the use of different optical flow estimation methods for motion-compensated temporal processing in gated SPECT, of which the goal is to improve the accuracy of image reconstruction. In particular, we examine how much room is still left in optical flow estimation toward improving the reconstructed image quality. In our experiments we conducted a quantitative evaluation using simulated imaging study with multiple noise realizations from the NCAT phantom. As an upper bound, the known motion in NCAT was used for reconstruction. The results show that 4D reconstruction with a periodic optical flow model can achieve results almost matching that from the known motion.