Abstract:Originally published at: Lovric, Goran; Oberta, Peter; Mohacsi, Istvan; Stampanoni, Marco; Mokso, Rajmund (2014). A robust tool for photon source geometry measurements using the fractional Talbot effect. Optics Express, 22(3):2745. DOI: https://doi.org/10.1364/OE.22.002745A robust tool for photon source geometry measurements using the fractional Talbot effect Paul Scherrer Institute, 5232 Villigen, Switzerland *goran.lovric@psi.ch Abstract: A reliable measurement of beam coherence is important for optim… Show more
“…Right tibiae were mechanically fixed with wax to prevent sample movement and the tibiofibular junctions were scanned using SR CT at the TOMCAT beamline of the Swiss Light Source at a voxel size of 1.3 μm and 325 nm (with the highest the spatial resolution needed to detect the presence and size of smallest intracortical capillaries) at two different sample-to-detector distances, (15 and 25 mm, for standard X-ray tomography and phase-sensitive imaging respectively,) 33 , 34 (Fig. 1b,c ).…”
3D imaging of the bone vasculature is of key importance in the understanding of skeletal disease. As blood vessels in bone are deeply encased in the calcified matrix, imaging techniques that are applicable to soft tissues are generally difficult or impossible to apply to the skeleton. While canals in cortical bone can readily be identified and characterised in X-ray computed tomographic data in 3D, the soft tissue comprising blood vessels that are putatively contained within the canal structures does not provide sufficient image contrast necessary for image segmentation. Here, we report an approach that allows for rapid, simultaneous visualisation of calcified bone tissue and the vasculature within the calcified bone matrix. Using synchrotron X-ray phase contrast-enhanced tomography we show exemplar data with intracortical capillaries uncovered at sub-micrometre level without the need for any staining or contrast agent. Using the tibiofibular junction of 15 week-old C57BL/6 mice post mortem, we show the bone cortical porosity simultaneously along with the soft tissue comprising the vasculature. Validation with histology confirms that we can resolve individual capillaries. This imaging approach could be easily applied to other skeletal sites and transgenic models, and could improve our understanding of the role the vasculature plays in bone disease.
“…Right tibiae were mechanically fixed with wax to prevent sample movement and the tibiofibular junctions were scanned using SR CT at the TOMCAT beamline of the Swiss Light Source at a voxel size of 1.3 μm and 325 nm (with the highest the spatial resolution needed to detect the presence and size of smallest intracortical capillaries) at two different sample-to-detector distances, (15 and 25 mm, for standard X-ray tomography and phase-sensitive imaging respectively,) 33 , 34 (Fig. 1b,c ).…”
3D imaging of the bone vasculature is of key importance in the understanding of skeletal disease. As blood vessels in bone are deeply encased in the calcified matrix, imaging techniques that are applicable to soft tissues are generally difficult or impossible to apply to the skeleton. While canals in cortical bone can readily be identified and characterised in X-ray computed tomographic data in 3D, the soft tissue comprising blood vessels that are putatively contained within the canal structures does not provide sufficient image contrast necessary for image segmentation. Here, we report an approach that allows for rapid, simultaneous visualisation of calcified bone tissue and the vasculature within the calcified bone matrix. Using synchrotron X-ray phase contrast-enhanced tomography we show exemplar data with intracortical capillaries uncovered at sub-micrometre level without the need for any staining or contrast agent. Using the tibiofibular junction of 15 week-old C57BL/6 mice post mortem, we show the bone cortical porosity simultaneously along with the soft tissue comprising the vasculature. Validation with histology confirms that we can resolve individual capillaries. This imaging approach could be easily applied to other skeletal sites and transgenic models, and could improve our understanding of the role the vasculature plays in bone disease.
“…The sample to detector distance z was set to 100 mm, yielding an optimal trade-off between contrast-to-noise ratio and resolution settings 40 and at the same time keeping the penumbral blurring at a minimum, i.e. with projected X-ray source sizes (full width at half maximum) being 0.51 μm and 0.18 μm in the horizontal and vertical direction, respectively 42 . Figure 7 Schematic description of the imaging layout ( a ) at the X02DA TOMCAT beamline with the ( b ) complete triggering schematic for the prospective heartbeat-triggered gating technique and ( c ) the final in vivo endstation design with all accompanying components.…”
Lungs represent the essential part of the mammalian respiratory system, which is reflected in the fact that lung failure still is one of the leading causes of morbidity and mortality worldwide. Establishing the connection between macroscopic observations of inspiration and expiration and the processes taking place at the microscopic scale remains crucial to understand fundamental physiological and pathological processes. Here we demonstrate for the first time in vivo synchrotron-based tomographic imaging of lungs with pixel sizes down to a micrometer, enabling first insights into high-resolution lung structure. We report the methodological ability to study lung inflation patterns at the alveolar scale and its potential in resolving still open questions in lung physiology. As a first application, we identified heterogeneous distension patterns at the alveolar level and assessed first comparisons of lungs between the in vivo and immediate post mortem states.
“…It is difficult to reveal weakly absorbing structures of soft tissues consisting of low‐Z elements (such as C, H, O, N, and so on) due to poor image contrast arisen from soft tissues almost transparent to hard X‐rays. Compared with traditional micro‐CT based on the attenuation effect, the phase sensitive imaging technique generally provides much higher image contrast and lower radiation dose for low‐Z elemental samples . Therefore, X‐ray phase‐contrast imaging (XPCI) enables us to observe inner weakly absorbing structures with high phase sensitivity, particularly suitable for visualizing and quantifying fine electron density differences of biomedical structural information with sufficient image contrast.…”
Section: Introductionmentioning
confidence: 99%
“…image contrast and lower radiation dose for low-Z elemental samples. [4][5][6] Therefore, X-ray phase-contrast imaging (XPCI) enables us to observe inner weakly absorbing structures with high phase sensitivity, particularly suitable for visualizing and quantifying fine electron density differences of biomedical structural information with sufficient image contrast. In recent years, many XPCI techniques, including crystal interferometry, analyzer-based imaging, grating-based imaging, and propagation-based imaging, have been proposed and developed to improve hard X-ray image contrast through translating the phase shift into the accessibly recorded intensity variations.…”
Synchrotron‐based X‐ray phase sensitive micro‐tomography techniques enable to visualize detailed three‐dimensional (3D) insight into nondestructive inner‐structure of biomedical samples. Different phase sensitive mechanisms have been employed for discrimination of tissue's tiny density variations in biomedical research. We effectively visualized and analyzed the phase‐contrast experimental results of X‐ray grating‐based imaging, based on grating interferometry with phase stepping, by using transgenic mouse fetus. We quantitatively measured and evaluated the contrast‐to‐noise ratio or the mass density resolution, spatial resolution, radiation dose, and figure of merit of X‐ray grating‐based imaging technique in biomedical research respectively. Moreover, the complex coherent degrees of light source were duly taken into account in the analysis of spatial resolution. In addition, the mass density distribution of soft biomedical specimens can be estimated using our presented method preliminarily. For most soft tissue and organ observation, this work provides explicit guidelines to help future synchrotron users obtain the quantitative image information, suitable for their specific biomedical research.
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