Single shot x-ray phase contrast imaging using a direct conversion microstrip detector with single photon sensitivity

Abstract

X-ray phase contrast imaging enables the measurement of the electron density of a sample with high sensitivity compared to the conventional absorption contrast. This is advantageous for the study of dose-sensitive samples, in particular, for biological and medical investigations. Recent developments relaxed the requirement for the beam coherence, such that conventional X-ray sources can be used for phase contrast imaging and thus clinical applications become possible. One of the prominent phase contrast imaging methods, Talbot-Lau grating interferometry, is limited by the manufacturing, alignment, and photon absorption of the analyzer grating, which is placed in the beam path in front of the detector. We propose an alternative improved method based on direct conversion charge integrating detectors, which enables a grating interferometer to be operated without an analyzer grating. Algorithms are introduced, which resolve interference fringes with a periodicity of 4.7 μm recorded with a 25 μm pitch Si microstrip detector (GOTTHARD). The feasibility of the proposed approach is demonstrated by an experiment at the TOMCAT beamline of the Swiss Light Source on a polyethylene sample.

Quantitative X-ray phase contrast computed tomography with grating interferometry

“…Yet, the availability of the electron density with high accuracy renders GBPC-CT eminently interesting for quantitative biomedical and material science micro-CT applications. Further development of spectral detectors [143], using a combination of analyzer grating and detector [189], or the implementation of a dual phase grating approach [190][191][192] is expected to increase the performance of laboratory GBPC-CT in the near future.…”

X-ray dark-field contrast imaging of water transport during hydration and drying of early-age cement-based materials

“…Performing the Talbot On the other hand, advances in fabrication of the gratings, e.g., the production of gratings with larger surface area [92] and/or the realization of gratings working at higher design energies [93], will allow imaging larger specimens without significant decrease in spatial resolution, compared with the resolution achieved in this work. New approaches to performing Talbot-Lau interferometry [94][95][96][97] at different specimen orientations, combined with iterative tomographic reconstruction algorithms [98], will also allow in the next years increasing the temporal resolution of 3D, tomographic imaging such that it will become possible to investigate water transport in early-age cement-based materials fully (and more quantitatively) in 3D.…”

Trabecular bone anisotropy imaging with a compact laser-undulator synchrotron x-ray source

“…Another approach could be a so-called single shot technique, requiring that the fringes are directly resolved by the detector. It has been shown that this technique can reveal DFC-images for in-vivo objects with a dose comparable to conventional chest radiographs 23 – 25 . In contrast to conventional radiography, XVR detects subpixel-sized information.…”