ABSTRACT
This chapter presents the wave optical formulation of X-ray phase-contrast imaging and the different ways phase-contrast can be used to generate image contrast with and without optical elements. It introduces the interaction mechanism of X-rays with matter and describes the basic equations and the commonly used approximations in the study of the interaction of X-rays with macroscopic objects. The chapter looks at reconstructing the projected thickness of a monomorphous material using just a single analyzer-based phase-contrast (AB) image in the absence of ultrasmall-angle scattering (USAXS). It also looks at recovering the intensity and phase of the wavefield passing through an arbitrary object, that produces negligible USAXS, using two AB images. When USAXS makes a significant contribution to the image, a two-image reconstruction will yield considerable artefacts. The chapter provides the methods for recovering several X-ray interaction parameters using multiple AB images.
