Metal Artifacts Reduction in Computed Tomography: A Bilateral Reprojection Approach

Reducing artifacts owing to metallic objects in Computed Tomography (CT) is a challenging task. These metal induced anisotropic streaks are both signal dependent and difficult to distinguish from sharp edges. The method we propose is based on a non-iterative reprojection-reconstruction framework. It first identifies metal regions and bilateral filtering is used to deal with the streak artifacts. Refined projection data is obtained by replacing metal traces with projections of the bilateral filtered image. Metal regions were superimposed back for the final reconstruction. Experimental results demonstrate a significant reduction in the metal artifacts while preserving the edges for the underlying object.