Quantitative analysis of metal artifacts in X-ray tomography

Thursday, May 2, 2019 - 2:00pm - 2:50pm
Lind 305
Yiran Wang (Stanford University)
In X-ray CT scan with metallic objects, it is known that direct application of the filtered back-projection (FBP) formula leads to streaking artifacts in the reconstruction. These are characterized mathematically in terms of wave front sets in Seo et al [CPAM, 2017]. In this talk, we give a quantitative microlocal analysis of such artifacts. For metal regions with strictly convex smooth boundaries, we show that the streaking artifacts are conormal distributions to straight lines tangential to at least two boundary curves. For metal regions with piecewise smooth boundaries, we analyze the streaking artifacts especially due to the corner points. Finally, we discuss the reduction of the artifacts using appropriate filters. This is a joint work with B. Palacios and G. Uhlmann.