Alternative grating designs for cone-beam edge illumination X-ray phase contrast imaging

Abstract

Edge illumination X-ray phase contrast imaging is a method which relies on two gratings to obtain attenuation, phase and dark field contrast. Current gratings consist of periodic apertures in a high-absorbing flat plate. While edge illumination was originally designed for parallel-beam imaging, it also works with cone-beam sources when the opening angle is sufficiently low. With higher opening angles, however, current gratings cause a shadow which results in a decreased intensity. In this paper, three alternative grating geometries are studied with Monte-Carlo simulations and their performance is evaluated in terms of shadowing. Results show that the alternative grating geometries significantly reduce shadowing in cone-beam based edge illumination.