Iterative motion-aware reconstruction algorithm for cardiac cone beam CT

It is feasible, though challenging, to build a cone beam CT scanner with a rotating gantry that can make a full turn in about 270 ms and has a large area detector mounted to it. Given such a scanner, one might try to reconstruct a 3-D still image of the beating heart from a single circular short scan of the thorax. Such a scan would take about 150 ms, which is still appreciably longer than the resting phase of the heart. So even if the resting phase fell within the time window of the data acquisition, any reconstruction algorithm for static cone beam CT would produce an image still somewhat affected by motion artifacts. In this paper, it is proposed to avoid such artifacts by means of a motion-aware extension of the Algebraic Reconstruction Technique. The proposed algorithm solves a mathematical model of the data acquisition that allows the heart to move during the scan. The motion of the heart is represented by a vector field which is reconstructed jointly with the image and need not be known beforehand.