X‐ray bi‐prism interferometry—A design study of proposed novel hardware

Abstract

Purpose: Advances in X-ray phase-contrast imaging can obtain excellent soft-tissue contrast of phase-shift, attenuation, and small angle scatter. Here we present fringe patterns for different design parameters of Xray bi-prism interferometry imaging systems. Our aim is to develop bi-prism interferometry imaging systems with excellent polychromatic performance that produce high-contrast fringes with spatially incoherent X-ray illumination. We also introduce a novel X-ray tube design that uses temporal multiplexing to provide simultaneous virtual "electronic phase stepping" that replace "mechanical phase stepping" popular with grating-based interferometry setups. Methods:In our investigation we develop expressions for the irradiance distribution pattern of a bi-prism interferometer comprised of multiple point sources and multiple bi-prisms. These expressions are used to plot fringe patterns for X-ray design parameters including size of point source, number of point sources, and point source separation; and bi-prism design parameters including material, angle, number of biprisms, period, and bi-prism array to X-ray source and to detector distances. Results:Results show that the fringe patterns for a bi-prism interferometry system are not longitudinally periodic as with grating interferometers that produce a Talbot-Lau carpet. It is also shown that at 59 keV Xrays the bi-prism material should be something comparable to nickel to obtain reasonable fringe visibility. Conclusion:The irradiance distribution pattern demonstrates that bi-prism interferometry may provide comparable or improved fringe visibility to that of gratings. Special care is given to present our findings within the context of previous advancements. A single-shot image acquisition approach using a temporal multiplexed, high-power X-ray source provides virtual electronic phase stepping without focal spot sweeping. This provides multiple images, each at the same exposure and the same projection view, from different fringe locations that allow one to derive the attenuation, phase, and dark-field images of the sample without mechanical phase stepping of a grating.

An Analytical Algorithm for Tensor Tomography From Projections Acquired About Three Axes

“…In our simulations of this previous work, we used a wave optics approach to simulate the projections; whereas, in the present work we did not simulate a specific imaging modality but evaluated our filtered back-projection algorithm by numerically approximating the projections of a generic numerical tensor field and a diffusion tensor field of an excised human heart. Our future interests involve developing algorithms to directly reconstruct the tensor representation of small-angle scatter using X-ray bi-prism interferometry [96]. This interest is heightened by the fact that from the work of [15] it is appropriate to represent small-angle scatter as a second rank tensor of which one can measure longitudinal and transvers scalar projections of the tensor representation of small-angle scatter using X-ray darkfield imaging.…”

Wavefront division swept source OCT

“…Wavefront division methods are traditional and established concepts in interferometric approaches that can be tracked over a long time [1]. Starting already with Youngs double slit experiments they can be continued with (bi-)prism based WD configurations, meanwhile mostly applied for X-ray or electron beam interferometry [2], [3] or in holography [4]. From a wider point of view also (versions of) laser Doppler velocimetry [5], phase contrast microscopy [6], and wavefront sensors [7] can be assigned to such WD-based sensing methods.…”