Tomographic reconstruction of three-dimensional objects from hard X-ray differential phase contrast projection images
01 Oct 2007-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment (North-Holland)-Vol. 580, Iss: 2, pp 925-928
TL;DR: In this article, a method for tomographic phase contrast imaging of centimeter sized objects was proposed based on a hard X-ray grating interferometer, which has been demonstrated to yield differential phase contrast projection images.
Abstract: We report on a method for tomographic phase contrast imaging of centimeter sized objects. As opposed to existing techniques, our approach can be used with low-brilliance, lab based X-ray sources and thus is of interest to a wide range of applications in medicine, biology, and non-destructive testing. The work is based on the recent development of a hard X-ray grating interferometer, which has been demonstrated to yield differential phase contrast projection images. Here we particularly focus on how this method can be used for tomographic reconstructions using filtered backprojection algorithms to yield quantitative volumetric information of the real part of the samples's refractive index.
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TL;DR: A review of the areas in which ideas from coherent X-ray methods are contributing to methods for the neutron, electron and optical communities is presented in this article, along with associated experiments in materials science.
Abstract: X-ray sources are developing rapidly and their coherent output is growing correspondingly. The increased coherent flux from modern X-ray sources is being matched with an associated development in experimental methods. This article reviews the literature describing the ideas that utilize the increased brilliance from modern X-ray sources. It explores how ideas in coherent X-ray science are leading to developments in other areas, and vice versa. The article describes measurements of coherence properties and uses this discussion as a base from which to describe partially coherent diffraction and X-ray phase-contrast imaging, with applications in materials science, engineering and medicine. Coherent diffraction imaging methods are reviewed along with associated experiments in materials science. Proposals for experiments to be performed with the new X-ray free-electron lasers are briefly discussed. The literature on X-ray photon-correlation spectroscopy is described and the features it has in common with other coherent X-ray methods are identified. Many of the ideas used in the coherent X-ray literature have their origins in the optical and electron communities and these connections are explored. A review of the areas in which ideas from coherent X-ray methods are contributing to methods for the neutron, electron and optical communities is presented.
450 citations
Cites background from "Tomographic reconstruction of three..."
...sources and they have extended these ideas to tomographic imaging [155, 158, 159]....
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TL;DR: It is demonstrated how the soft tissue sensitivity of the technique is increased and in vitro tomographic images of a tumor bearing rat brain sample are shown, without use of contrast agents.
Abstract: We report on significant advances and new results concerning a recently developed method for grating-based hard x-ray phase tomography. We demonstrate how the soft tissue sensitivity of the technique is increased and show in vitro tomographic images of a tumor bearing rat brain sample, without use of contrast agents. In particular, we observe that the brain tumor and the white and gray brain matter structure in a rat's cerebellum are clearly resolved. The results are potentially interesting from a clinical point of view, since a similar approach using three transmission gratings can be implemented with more readily available x-ray sources, such as standard x-ray tubes. Moreover, the results open the way to in vivo experiments in the near future.
223 citations
TL;DR: In this article, an inverse interferometer geometry is investigated that offers significant advantages for grating fabrication and for the application of the method in computed tomography (CT) scanners, where the sample should be placed in front of or behind the phase grating.
Abstract: Phase-contrast imaging using conventional polychromatic x-ray sources and grating interferometers has been developed and demonstrated for x-ray energies up to 60 keV. Here, we conduct an analysis of possible grating configurations for this technique and present further geometrical arrangements not considered so far. An inverse interferometer geometry is investigated that offers significant advantages for grating fabrication and for the application of the method in computed tomography (CT) scanners. We derive and measure the interferometer’s angular sensitivity for both the inverse and the conventional configuration as a function of the sample position. Thereby, we show that both arrangements are equally sensitive and that the highest sensitivity is obtained, when the investigated object is close to the interferometer’s phase grating. We also discuss the question whether the sample should be placed in front of or behind the phase grating. For CT applications, we propose an inverse geometry with the sample ...
184 citations
TL;DR: The use of phase-contrast imaging and tomography for a wide variety of materials science characterization problems is reviewed using both synchrotron and laboratory sources and the particular benefits of phase contrast in the laboratory setting are demonstrated.
Abstract: X-ray phase-contrast imaging and tomography make use of the refraction of X-rays by the sample in image formation. This provides considerable additional information in the image compared to conventional X-ray imaging methods, which rely solely on X-ray absorption by the sample. Phase-contrast imaging highlights edges and internal boundaries of a sample and is thus complementary to absorption contrast, which is more sensitive to the bulk of the sample. Phase-contrast can also be used to image low-density materials, which do not absorb X-rays sufficiently to form a conventional X-ray image. In the context of materials science, X-ray phase-contrast imaging and tomography have particular value in the 2D and 3D characterization of low-density materials, the detection of cracks and voids and the analysis of composites and multiphase materials where the different components have similar X-ray attenuation coefficients. Here we review the use of phase-contrast imaging and tomography for a wide variety of materials science characterization problems using both synchrotron and laboratory sources and further demonstrate the particular benefits of phase contrast in the laboratory setting with a series of case studies.
166 citations
TL;DR: The first experimental soft-tissue phase-contrast tomography results using a conventional x-ray tube source, with a millimeter-sized focal spot, are reported, demonstrating the advantageous contrast attainable through phase- Contrast imaging over conventional attenuation-based approaches.
Abstract: We report the first experimental soft-tissue phase-contrast tomography results using a conventional x-ray tube source, with a millimeter-sized focal spot. The setup is based on a Talbot-Lau grating interferometer operated at a mean energy of 28 keV. We present three-dimensional ex vivo images of a chicken heart sample, fixated in formalin. The results clearly demonstrate the advantageous contrast attainable through phase-contrast imaging over conventional attenuation-based approaches.
147 citations
References
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01 Jan 1959
TL;DR: In this paper, the authors discuss various topics about optics, such as geometrical theories, image forming instruments, and optics of metals and crystals, including interference, interferometers, and diffraction.
Abstract: The book is comprised of 15 chapters that discuss various topics about optics, such as geometrical theories, image forming instruments, and optics of metals and crystals. The text covers the elements of the theories of interference, interferometers, and diffraction. The book tackles several behaviors of light, including its diffraction when exposed to ultrasonic waves.
19,815 citations
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01 Oct 1999
TL;DR: In this article, the authors discuss various topics about optics, such as geometrical theories, image forming instruments, and optics of metals and crystals, including interference, interferometers, and diffraction.
Abstract: The book is comprised of 15 chapters that discuss various topics about optics, such as geometrical theories, image forming instruments, and optics of metals and crystals. The text covers the elements of the theories of interference, interferometers, and diffraction. The book tackles several behaviors of light, including its diffraction when exposed to ultrasonic waves.
19,503 citations
TL;DR: In this article, a setup consisting of three transmission gratings can efficiently yield quantitative differential phase-contrast images with conventional X-ray tubes, which can be scaled up to large fields of view.
Abstract: X-ray radiographic absorption imaging is an invaluable tool in medical diagnostics and materials science. For biological tissue samples, polymers or fibre composites, however, the use of conventional X-ray radiography is limited due to their weak absorption. This is resolved at highly brilliant X-ray synchrotron or micro-focus sources by using phase-sensitive imaging methods to improve the contrast1,2. However, the requirements of the illuminating radiation mean that hard-X-ray phase-sensitive imaging has until now been impractical with more readily available X-ray sources, such as X-ray tubes. In this letter, we report how a setup consisting of three transmission gratings can efficiently yield quantitative differential phase-contrast images with conventional X-ray tubes. In contrast with existing techniques, the method requires no spatial or temporal coherence, is mechanically robust, and can be scaled up to large fields of view. Our method provides all the benefits of contrast-enhanced phase-sensitive imaging, but is also fully compatible with conventional absorption radiography. It is applicable to X-ray medical imaging, industrial non-destructive testing, and to other low-brilliance radiation, such as neutrons or atoms.
1,789 citations
TL;DR: In this paper, a simplified scheme for phase-contrast imaging based on an X-ray source having high spatial (but essentially no chromatic) coherence is presented. But the method is not suitable for large areas of irradiation, and it can operate with a lower absorbed dose than traditional Xray imaging techniques, and should find broad application in clinical, biological and industrial settings.
Abstract: IN conventional radiography, X-rays which pass through an object along different paths are differentially absorbed, and the intensity pattern of the emerging beam records the distribution of absorbing materials within the sample. An alternative approach is phase-contrast radiography, which instead records variations of the phase of the emerging radiation. Such an approach offers improved contrast sensitivity, especially when imaging weakly absorbing samples. Unfortunately, current phase-contrast imaging techniques1–11 generally require highly monochromatic plane-wave radiation and sophisticated X-ray optics, so their use is greatly restricted. Here we describe and demonstrate a simplified scheme for phase-contrast imaging based on an X-ray source having high spatial (but essentially no chromatic) coherence. The method is compatible with conventional polychromatic micro-focus X-ray tube sources, is well suited to large areas of irradiation, can operate with a lower absorbed dose than traditional X-ray imaging techniques, and should find broad application in clinical, biological and industrial settings.
1,673 citations
TL;DR: This work demonstrates simultaneous phase and amplitude extraction from a single defocused image of a homogeneous object and solves the twin‐image problem of in‐line holography and is capable of analysing data obtained using X‐ray microscope, electron microscopy, neutron microscopy or visible‐light microscopy.
Abstract: We demonstrate simultaneous phase and amplitude extraction from a single defocused image of a homogeneous object. Subject to the assumptions explicitly stated in the derivation, the algorithm solves the twin-image problem of in-line holography and is capable of analysing data obtained using X-ray microscopy, electron microscopy, neutron microscopy or visible-light microscopy, especially as they relate to defocus and point projection methods. Our simple, robust, non-iterative and computationally efficient method is applied to data obtained using an X-ray phase contrast ultramicroscope.
1,589 citations