ABSTRACT
This chapter explains crystal analyzer-based X-ray phase-contrast imaging (XPCI) and introduces the basis of XPCI. It describes the theory of X-ray dynamical diffraction and presents an algorithm especially for 3D image reconstruction. In XPCI, reflection or transmission by crystal is used. The efficiency of diffraction by crystal dramatically changes when the angle of incident is changed close to the Bragg angle. XPCI optics comprise a monochromator-collimator and an angle analyzer crystal. The X-ray dynamical diffraction theory accurately describes the interaction of X-ray plane waves with a perfect crystal lattice in both geometries: Bragg case and Laue case. In order to derive the computed tomography (CT) reconstruction algorithm, the relationship between the ray propagation path and the physical quantity on the path must be clarified. In a case where a sample includes hard tissues such as calcification or bone, conspicuous artifacts like metal artifacts in ordinary CT may appear throughout a refraction-contrast CT image.
