Today’s commercial X-ray micro computed tomography (CT) specimen systems are based on microfocus sources, 2D pixel array cameras and short source-to-detector distances (i.e. cone-beam configurations). High resolution is achieved by means of geometric magnification. The further development of such devices to acquire phase and scattering contrast images can dramatically enhance their range of applications. Due to the compact geometries, which imply a highly diverging beam, the gratings must be curved to maintain highest imaging performance over a large field of view. We report about the implementation of extremely compact Talbot and Talbot- Lau type grating interferometers which are compatible to the geometry of typical micro CT systems. For the analytical description of the imaging system, formulas are presented describing the dependency of the sensitivity on geometric parameters, camera and source parameters. Further, the imaging pipeline consisting of the data acquisition protocol, radiographic phase retrieval and tomographic image reconstruction is illustrated. The reported methods open the way for an immediate integration of phase and scattering contrast imaging on table top X-ray micro CT scanners.

Date Published: 6 March 2013
PDF: 7 pages
Proc. SPIE 8668, Medical Imaging 2013: Physics of Medical Imaging, 866813 (6 March 2013); doi: 10.1117/12.2006865

Published in SPIE Proceedings Vol. 8668:
Medical Imaging 2013: Physics of Medical Imaging
Robert M. Nishikawa; Bruce R. Whiting; Christoph Hoeschen, Editor(s)