Replacing the detector mask with a structured scintillator in edge-illumination x-ray phase contrast imaging

Abstract

We present a proof-of-concept edge illumination x-ray phase contrast system where the detector mask has been replaced by an indirect conversion detector in which sensitive and insensitive regions have been obtained by “patterning” the scintillator. This was achieved by creating a free-standing grid with period and aperture size matching that of a typical detector mask and filling the apertures with gadolinium oxysulfide. Images of various samples were collected with both the modified and the original edge illumination systems based on the use of two masks to characterize the performances of this detector design. We found that, despite the proof-of-concept nature of this attempt resulting in a structured detector with suboptimal performance, it allows effective separation of the attenuation and refraction channels through phase retrieval and the visualization of hard-to-detect features such as cartilage through the latter channel, thus demonstrating that the proposed approach holds the potential to lead to improved stability since it will use a single optical element facilitating the design of rotating phase contrast systems or the retrofitting of conventional x-ray systems.