Effect of detector in-plane rotation misalignment on dimensional measurements using helical CT acquisition.

Abstract

One of the critical factors that may significantly contribute to X-ray computed tomography measurement uncertainty is the misalignment of CT system components from ideal geometry assumed by tomographic reconstruction. It is proven to cause image artifacts, inhomogeneous magnification, thus leading to dimensional measurement errors. There is a lack of studies on helical trajectory scanning in metrological applications, focusing on the detector's angular misalignments. We will present results of CT measurements with misaligned detector by in-plane rotation for circular, double-helix, and space-filling trajectory. They prove that such misalignment may cause significant measurements errors, depending on the misalignments magnitude and applied acquisition trajectory.