Physical model of image formation in multiple-image radiography

We have recently proposed a new X-ray imaging method, called multiple-image radiography (MIR), which simultaneously produces images of absorption, refraction, and ultra-small-angle scatter, while rejecting higher-angle scatter. This paper presents a theoretical model of the relevant X-ray propagation mechanisms, thereby explaining why MIR works. Specifically, beam propagation is computed through a stratified scattering medium in an ultra-small-angle regime. This analysis demonstrates that the MIR images are linear with object thickness, which is a requirement for computed tomography by standard reconstruction methods.