Application of Absorption and Refraction Matching Techniques for Diffraction Enhanced Imaging

Diffraction Enhanced x-ray Imaging (DEI) derives contrast from absorption (as does conventional radiography), gradient in x-ray index of refraction and scatter-rejection (extinction). The combination of these contrast mechanisms generally allows more features in objects to be observed compared to conventional radiography [1]. In some instances or in specially prepared systems it is possible to eliminate one or more of the contrast mechanisms so as to create images that arise from a single contrast mechanism. With DEI it is most interesting to either eliminate the absorption contrast of an object or eliminate the refraction gradient contrast. We have explored both cases in order to better understand and exploit the absence of a contrast mechanism for practical imaging applications.