Time-resolved cardiac CT reconstruction using the ensemble Kalman Filter

We propose an algorithm to solve the problem of Time-Resolved Cardiac Computed Tomography (CT). The algorithm reconstructs a snapshot of the moving heart at any time instant from CT projection data acquired over a single heart-cycle. The object is modeled by a spatio-temporal state-space model, and an ensemble Kalman Filter (a Monte-Carlo approximation to the Kalman filter) is used to assimilate the sequentially acquired projection data. Simulation results of the dynamic NCAT cardiac phantom, under the fan-beam geometry and a two-source CT system, show reconstructions that are free of the motion artifacts that mar conventional methods.