A ring artifact suppression algorithm based on a priori information

In this letter, ring artifacts in two-dimensional (2D) tomographic slices are considered. For a parallel beam geometry we propose an interactive algorithm, which removes the artifacts while preserving fine image details. The algorithm comprises two stages and is based on a priori information about the true attenuation coefficient in some areas of a 2D slice. Even in the absence of any a priori information the initial stage of the algorithm can already provide good ring artifact suppression.