Improvement of CT metal artifact reduction using trace repairation

Metal artifacts drastically impair the image quality in CT images and often reduce their diagnostic value. Considering the reliability and timeliness of the clinical data, the typical NMAR(Normalized MAR) algorithm is in general successful in removing metal artifacts, and contains the least residual and newly-introduced artifacts. However, in some circumstances metals are adjacent to bones of high density, that will inevitably induce the new artifacts or residual artifacts between the bones and metals. Based on NMAR, this paper introduces the Trace-based Normalized Metal Artifact Reduction (TNMAR). Specifically, during the normalized regional repair in sinogram, we introduce the bone-trace-based repair. It considerably reduced the newly introduced metal artifacts between the bones and metals, while greatly preserving the orignal high contrast and the accuracy of tissue details. In clinical medicine, it has great application value.