4D reconstruction of gated cardiac SPECT using fourier harmonics

We propose a four-dimensional reconstruction method for noise reduction in gated cardiac SPECT images. Aiming to exploit the periodic nature of cardiac motion, we use a Fourier harmonic representation to model the image activities along the gated temporal dimension. We develop a penalized least-squares approach to reconstruct the different harmonics in the representation model, which also takes into account spatial smoothing. The proposed method is demonstrated using simulated cardiac perfusion imaging based on the NURBS-based cardiac-torso (NCAT) phantom. Our results show that it could lead to improved reconstruction of the gated images.