19 March 2013 Artifacts in X-ray dark-field measurements
Author Affiliations +
Proceedings Volume 8668, Medical Imaging 2013: Physics of Medical Imaging; 866855 (2013) https://doi.org/10.1117/12.2008059
Event: SPIE Medical Imaging, 2013, Lake Buena Vista (Orlando Area), Florida, United States
Grating-based X-ray phase-contrast imaging with a Talbot-Lau interferometer is a promising method which might be able to increase soft tissue contrast and to gain additional information in comparison to attenuationbased imaging. The method provides an attenuation image, a differential phase image and a dark-field image. A conventional polychromatic X-ray tube can be used together with a Talbot-Lau interferometer consisting of a source grating, a phase grating and an absorption grating. The dark-field image shows information about the sub-pixel-size granularity of the measured object. This supplemental information is supposed to be suitable in applications, such as mammography or nondestructive testing. In this contribution we present results of measurements investigating the thickness-dependent behavior of dark-field imaging. The measurements are performed with a wedge-shaped, granular object with our X-ray phase-contrast imaging set-up and calculating the dark-field image. Measurements with this special phantom show a resurgence of visibility contrast with increasing thickness of the object after passing a minimum. The reason of this artifact is not completely clear up to now, but might be found in attenuation effects in the object in combination with the polychromatic X-ray spectrum or in residual amplitudes in our fitting algorithm for low visibilities and low intensities at large thicknesses. Understandig the thickness-dependent behavior of the X-ray dark-field advances the understanding of the formation of the dark-field image.
© (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Florian Horn, Florian Horn, Florian Bayer, Florian Bayer, Karl Gödel, Karl Gödel, Wilhelm Haas, Wilhelm Haas, Georg Pelzer, Georg Pelzer, Jens Rieger, Jens Rieger, André Ritter, André Ritter, Thomas Weber, Thomas Weber, Andrea Zang, Andrea Zang, Jürgen Durst, Jürgen Durst, Thilo Michel, Thilo Michel, Gisela Anton, Gisela Anton, "Artifacts in X-ray dark-field measurements", Proc. SPIE 8668, Medical Imaging 2013: Physics of Medical Imaging, 866855 (19 March 2013); doi: 10.1117/12.2008059; https://doi.org/10.1117/12.2008059

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