An image reconstruction algorithm for time varying X-ray projection image sequences

A new method to improve the spatial resolution in reconstructed images of moving objects using high-speed CT is described. Improvement is obtained by providing the reconstruction algorithm with increased number of views. This is done by mathematically estimating projections around the moving object corresponding to a given instant of time with the aid of Kalman-type filters. The variations of the projection data as a function of time is modeled using a discrete time state space model. A discrete transformation is used to map the signal dependent nature of the noise into a signal independent one. Results of several computer simulations using the algorithm are presented.