Analytical reconstruction of 4-D dynamic cardiac SPECT with noise-reduction and non-uniform attenuation compensation

Background: This study focuses on quantitative reconstruction of dynamic cardiac SPECT. Material and methods: The Karhunen-Loeve (KL) transform is first applied to gated frames or sinogram data to de-correlate the dynamic information along the time direction. Then the Poisson noise is treated by a penalized weighted least-squares minimization, followed by an analytical inversion of the treated sinograms with attenuation compensation via the Novikov formula. The reconstruction is completed by inverse KL transform. Results: Dynamic or gated cardiac sinograms were simulated from the NCAT phantom mimicking the human torso, and their reconstructions by the presented method showed significant improvement over the conventional methods of frame-by-frame reconstruction. Conclusion: This analytical reconstruction of dynamic SPECT is consistent and efficient with a good potential for practical use.