Improved resolution in x-ray tomography by super-resolution

Appl Opt. 2021 Jul 10;60(20):5783-5794. doi: 10.1364/AO.427934.


In this paper, super-resolution imaging is described and evaluated for x-ray tomography and is compared with standard tomography and upscaling during reconstruction. Blurring is minimized due to the negligible point spread of photon counting detectors and an electromagnetically movable micro-focus x-ray spot. Scans are acquired in high and low magnification geometry, where the latter is used to minimize penumbral blurring from the x-ray source. Sharpness and level of detail can be significantly increased in reconstructed slices to the point where the source size becomes the limiting factor. The achieved resolution of the different methods is quantified and compared using biological samples via the edge spread function, modulation transfer function, and Fourier ring correlation.