Intersection line length normalization in CT projection data

Abstract

We present a method to improve the quality of common sinogram restoration algorithms, which are used for metal-artifact reduction in X-ray CT. The presented approach is based on the idea that the intersection length of all beams through the object of interest can approximately be calculated from a preliminary reconstruction of the object. Incorporating this information to the reconstruction allows significant reduction of streak artifacts. Additionally, it is shown that the information about intersection length may also be used to improve the detection of metal shadows within the sinogram.