Comparison of Two Different Approaches for Spatial Resolution Determination for X-ray Computed Tomography with Helical Scanning Trajectory

The spatial resolution is still one of the essential parameters quantified in X-ray micro Computed Tomography for industrial applications. There is a number of approaches, how can be the spatial resolution determined. Our paper presents two of them: evaluation of the ruby sphere according to the ASTM E1695–95 guideline and bar pattern recognition included in the nanoQRM phantom. The main aim of this paper is to point out the aspects of the spatial resolution determination according to the selected approaches and to compare the possible differences in the resulting spatial resolution. Both approaches were tested on a helical scanning trajectory utilizing one custom–made phantom consisting of a ruby sphere and commercial nanoQRM within a single scan. Such a unique phantom allows for accurate comparison due to the ability to determine spatial resolution using both methods within a single scan. In general, both approaches determined the spatial resolution on the same value. The final difference is given by the discrete approach provided by nanoQRM.