Comparison of data-driven and external-surrogate based motion estimation strategies in cardiac SPECT imaging

Motion estimation strategies found in literature may be categorized primarily into two types: data-driven using the SPECT acquisition data itself to determine motion, and external surrogate-based, where motion is obtained from a dedicated motion-tracking system. The surrogate-based motion estimates though accurate, measure only the motion exhibited externally which may not correlate exactly with the movement of the heart inside the body, whereas the accuracy of data-driven strategies is limited by the type of motion to be estimated and various degrading factors such as noise, attenuation, scatter, and collimator blurring. The goal of this work is to evaluate and compare existing data-driven strategies for cardiac SPECT studies, and ultimately to devise methods to integrate the data-driven and surrogate-based motion estimation to overcome their individual limitations.