1. Phase Contrast Imaging with Coded Apertures Using Laboratory-Based X-ray Sources.
- Author
-
Ignatyev, K., Munro, P. R. T., Speller, R. D., and Olivo, A.
- Subjects
- *
SYNCHROTRONS , *PHASE contrast magnetic resonance imaging , *X-rays , *DETECTORS , *COHERENCE (Optics) , *ABSORPTION - Abstract
X-ray phase contrast imaging is a powerful technique that allows detection of changes in the phase of x-ray wavefronts as they pass through a sample. As a result, details not visible in conventional x-ray absorption imaging can be detected. Until recently the majority of applications of phase contrast imaging were at synchrotron facilities due to the availability of their high flux and coherence; however, a number of techniques have appeared recently that allow phase contrast imaging to be performed using laboratory sources. Here we describe a phase contrast imaging technique, developed at University College London, that uses two coded apertures. The x-ray beam is shaped by the pre-sample aperture, and small deviations in the x-ray propagation direction are detected with the help of the detector aperture. In contrast with other methods, it has a much more relaxed requirement for the source size (it works with source sizes up to 100 μm). A working prototype coded-aperture system has been built. An x-ray detector with directly deposited columnar CsI has been used to minimize signal spill-over into neighboring pixels. Phase contrast images obtained with the system have demonstrated its effectiveness for imaging low-absorption materials. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF