Reduction of Ring Artifacts in Computer Tomography

Artifacts in projection data and images obtained by medical X-ray computer tomography were analyzed. A general-purpose tomographic image reconstruction unit was used to clarify and elaborate the artifact simulation mechanism. It allows corrupted data to be input at different stages of the image reconstruction procedure. Introduction of these data leads to occurrence of image artifacts. The artifact simulation was used to develop filtering procedures for reduction of artifacts and evaluate the filter effectiveness. An effective method for reduction of artifacts in tomographic images based on projection data filtering was found.