Small and Ultra-Small Angle X-Ray Scattering Contrast Obtained With a Synchrotron-Based Shack–Hartmann Imaging System

A number of phase based X-ray imaging methods have been developed that derive contrast from phase effects from the object which make them particularly interesting because of the ability to visualize soft tissues. Shack-Hartmann is a wave-front diagnostic technique that emerged from optics which uses ray-line beams (beamlets) to interrogate the differences in the wave-front across a beam can also be used for X-ray imaging applications with phase sensitivity. This method, which has been applied in the X-ray regime, is very simple in that it only requires a screen to prepare an array of beamlets that then pass through the object and are allowed to propagate a distance onto a pixelated detector. Absorption and refraction information can be extracted from the detected beamlets. An untapped property is the additional ability to extract scatter distribution information based on the observed width of the detected spots. This paper describes experiments done at a synchrotron facility investigating the use of a Shack-Hartmann system for biomedical applications and include our method and examples of scatter contrast extraction from the method.