An image reconstruction method for improving CT spatial resolution

In order to improve the spatial resolution of industrial computed tomography (CT) without changing the hardware, the half-pixel offset scanning mode was analyzed and a direct reconstruction algorithm, which was based on the algebraic iteration technique, was proposed. This algorithm adopted area-weight to execute directly the iterative update of the reconstructed value using the acquired projection data. Computer simulation analysis with a star-type spatial resolution phantom was implemented and a modulation of 0.8 was reached at the cut-off frequency. It demonstrates that the proposed method has the potential of improving the spatial resolution. The industrial CT experimental results of a standard spatial resolution phantom validate the feasibility and the effect of the method. The proposed approach is easy to implement and has a promising application future.