Metal artifact reduction in X-ray CT imaging based on iterative reconstruction approach

X-ray computed tomography (CT) is a non-destructive technique useful for visualization of the internal structure of objects and is a power diagnosis tool in the field of biomedical engineering. However, due to the presence of high attenuating objects like metals, the reconstructions produced by typical CT reconstruction algorithm i.e. Filtered Back Projection (FBP) are heavily affected by the metal artifacts. Due to these artifacts, the interpretation of CT images is highly compromised. In this article, a metal artifact reduction approach based on iterative reconstruction is presented and demonstrated by an experiment using a specially designed biomedical specimen consisting of muscles, bones and metals. The basic concept is to remove the inaccurate metal artifacts pixels in the original CT image iteratively and then exactly reconstruct the soft-tissue using the forward projections with no metal information. During the reconstruction, artifacts are reduced by replacing the metal projection using the forward projection. The presented work is of interest for CT biomedical applications.