Motion-compensated dynamic image reconstruction for gated cardiac SPECT

In this paper we propose a unified image reconstruction procedure for dynamic images from traditional gated SPECT acquisition. We divide the cardiac cycle into a number of gate intervals as in gated SPECT, but treat the tracer distribution for each gate as a time-varying signal. By using dynamic expectation maximization and motion-compensated temporal regularization, our reconstruction procedure can produce an image sequence that shows both cardiac motion and time-varying tracer distribution simultaneously. We simulated gated cardiac perfusion imaging using the gated mathematical cardiac-torso (gMCAT) phantom with Tc99m-Teboroxime dynamics. Our experimental results show that the proposed methods can produce more accurate reconstruction of gated dynamic images than independent reconstruction of individual gate frames with spatial smoothness alone.