X-ray microtomography setup for absorption and diffraction tomography

2018 ◽  
Vol 84 (12) ◽  
pp. 32-39
Author(s):  
V. E. Asadchikov ◽  
A. V. Buzmakov ◽  
I. G. Dyachkova ◽  
D. A. Zolotov ◽  
Yu. S. Krivonosov ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Research Centre ◽  
Diffraction Reflection ◽  
Dislocation Loops ◽  
X Ray ◽  
Silicon Crystals ◽  
Dimensional Reconstruction ◽  
Pure Cholesterol

The results of studying silicon single crystals and gallstones on a laboratory X-ray microtomograph with a spatial resolution of 10 µm (developed at the Federal Scientific Research Centre for «Crystallography and Photonics» of the Russian Academy of Sciences) are reviewed. The method of tomographic experiment included the use of a monochromatic «parallel beam» with subsequent three-dimensional reconstruction based on a set of two-dimensional projections. Topotomographic measurements were performed in the mode of rotation of the samples under study around the normal to the reflecting plane adjusted to the Laue diffraction reflection geometry, which made it possible to identify and study single dislocations in perfect silicon crystals. Simulation of the dislocation loops was carried out on the basis of numerical solution of the Takagi-Taupin equations. In-vitro microtomographic study of human gallstones revealed the layered structure of the gallstones which are close in composition to modifications of calcium carbonate. The internal structure of the stones is heterogeneous and contains numerous cavities and cracks formed upon their growth. At the same time, the evaluation of the porosity of gallstones is necessary, since the latter can affect the rate of stone dissolution in their treatment by litholytic methods. Linear attenuation coefficients of x-ray radiation of cholesterol-type gallstones were calculated from the measurement results. The good agreement of the experimentally obtained results and calculations based on tabular data for pure cholesterol is demonstrated which proved that the tomographic method can be used for in vivo diagnosis of cholesterol-type gallstones.

Ultrasonic three-dimensional reconstruction: In vitro and In vivo volume and area measurement

1994 ◽  
Vol 20 (8) ◽  
pp. 719-729 ◽  
Author(s):  
Timothy C. Hodges ◽  
Paul R. Detmer ◽  
David H. Burns ◽  
Kirk W. Beach ◽  
D.Eugene Strandness
Keyword(s):  
Three Dimensional ◽  
Area Measurement ◽  
Three Dimensional Reconstruction ◽  
Dimensional Reconstruction

Three-dimensional reconstruction of coronary stents in vivo based on motion compensated X-ray angiography

2007 ◽  
Author(s):  
Dirk Schäfer ◽  
Babak Movassaghi ◽  
Michael Grass ◽  
Gert Schoonenberg ◽  
Raoul Florent ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Coronary Stents ◽  
Three Dimensional Reconstruction ◽  
X Ray ◽  
Dimensional Reconstruction

The Effects of the Surface Topography of Micromachined Titanium Substrata on Cell Behavior in Vitro and in Vivo

1999 ◽  
Vol 121 (1) ◽  
pp. 49-57 ◽  
Author(s):  
D. M. Brunette ◽  
B. Chehroudi
Keyword(s):  
Surface Topography ◽  
Fibrous Tissue ◽  
Three Dimensional ◽  
Tissue Response ◽  
Cell Behavior ◽  
Tissue Organization ◽  
Dimensional Reconstruction ◽  
Microfabrication Techniques

Surface properties, including topography and chemistry, are of prime importance in establishing the response of tissues to biomaterials. Microfabrication techniques have enabled the production of precisely controlled surface topographies that have been used as substrata for cells in culture and on devices implanted in vivo. This article reviews aspects of cell behavior involved in tissue response to implants with an emphasis on the effects of topography. Microfabricated grooved surfaces produce orientation and directed locomotion of epithelial cells in vitro and can inhibit epithelial downgrowth on implants. The effects depend on the groove dimensions and they are modified by epithelial cell–cell interactions. Fibroblasts similarly exhibit contact guidance on grooved surfaces, but fibroblast shape in vitro differs markedly from that found in vivo. Surface topography is important in establishing tissue organization adjacent to implants, with smooth surfaces generally being associated with fibrous tissue encapsulation. Grooved topographies appear to have promise in reducing encapsulation in the short term, but additional studies employing three-dimensional reconstruction and diverse topographies are needed to understand better the process of connective-tissue organization adjacent to implants. Microfabricated surfaces can increase the frequency of mineralized bone-like tissue nodules adjacent to subcutaneously implanted surfaces in rats. Orientation of these nodules with grooves occurs both in culture and on implants. Detailed comparisons of cell behavior on micromachined substrata in vitro and in vivo are difficult because of the number and complexity of factors, such as population density and micromotion, that can differ between these conditions.

scholarly journals Fuzzy Visual Hull Algorithm for Three-Dimensional Shape Reconstruction of TKA Implants from X-Ray Cone-Beam Images

2010 ◽  
Vol 14 (2) ◽  
pp. 122-127 ◽  
Author(s):  
Syoji Kobashi ◽  
◽  
Nao Shibanuma ◽  
Yutaka Hata ◽  
◽  
...  
Keyword(s):  
Three Dimensional ◽  
Knee Kinematics ◽  
Shape Reconstruction ◽  
Cone Beam ◽  
Visual Hull ◽  
Metal Artifacts ◽  
X Ray ◽  
Voxel Space

Three-Dimensional (3-D) shape reconstruction of total knee arthroplasty (TKA) implantsin vivoplays a key role to investigate implanted knee kinematics. TKA implants typically consist of metal femoral and tibial components and a polyethylene tibial insert. X-ray computed tomography (CT) causes severe metal artifacts, making the 3-D shape in reconstructed images extremely difficult to understand. This article proposes a new method of 3-D reconstruction from X-ray cone-beam images. Called a fuzzy visual hull, it introduces fuzzy logic in recognizing X-ray images. X-ray cone-beam images are fuzzified and back-projected into a fuzzy voxel space. Defuzzifying the fuzzy voxel space enables the 3-D TKA implant shape to be reconstructed. The results of evaluation using TKA implantsin vitroand computer-synthesized images demonstrated that the fuzzy visual hull provides high robustness against noise added to X-ray cone-beam images. The new approach also reconstructed the 3-D polyethylene insert despite the difficulty of recognizing the region in conventional X-ray CT.

3-D reconstruction of molecular shape from microcrystal thin sections

1983 ◽  
Vol 41 ◽  
pp. 748-749
Author(s):  
S. Cusack ◽  
J.-C. Jésior
Keyword(s):  
Three Dimensional ◽  
Molecular Shape ◽  
Biological Molecules ◽  
Fourier Space ◽  
Single Particles ◽  
Thin Sections ◽  
Standard Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dimensional Reconstruction

Three-dimensional reconstruction techniques using electron microscopy have been principally developed for application to 2-D arrays (i.e. monolayers) of biological molecules and symmetrical single particles (e.g. helical viruses). However many biological molecules that crystallise form multilayered microcrystals which are unsuitable for study by either the standard methods of 3-D reconstruction or, because of their size, by X-ray crystallography. The grid sectioning technique enables a number of different projections of such microcrystals to be obtained in well defined directions (e.g. parallel to crystal axes) and poses the problem of how best these projections can be used to reconstruct the packing and shape of the molecules forming the microcrystal.Given sufficient projections there may be enough information to do a crystallographic reconstruction in Fourier space. We however have considered the situation where only a limited number of projections are available, as for example in the case of catalase platelets where three orthogonal and two diagonal projections have been obtained (Fig. 1).

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

Preparation of cultured astrocytes for x-ray microanalysis

1989 ◽  
Vol 47 ◽  
pp. 988-989
Author(s):  
N.K.R. Smith ◽  
K.E. Hunter ◽  
P. Mobley ◽  
L.P. Felpel
Keyword(s):  
Cultured Cells ◽  
Elemental Content ◽  
Elemental Distribution ◽  
Sprague Dawley ◽  
X Ray ◽  
Cultured Astrocytes ◽  
Freeze Dried ◽  
Ultimate Objective

Electron probe energy dispersive x-ray microanalysis (XRMA) offers a powerful tool for the determination of intracellular elemental content of biological tissue. However, preparation of the tissue specimen , particularly excitable central nervous system (CNS) tissue , for XRMA is rather difficult, as dissection of a sample from the intact organism frequently results in artefacts in elemental distribution. To circumvent the problems inherent in the in vivo preparation, we turned to an in vitro preparation of astrocytes grown in tissue culture. However, preparations of in vitro samples offer a new and unique set of problems. Generally, cultured cells, growing in monolayer, must be harvested by either mechanical or enzymatic procedures, resulting in variable degrees of damage to the cells and compromised intracel1ular elemental distribution. The ultimate objective is to process and analyze unperturbed cells. With the objective of sparing others from some of the same efforts, we are reporting the considerable difficulties we have encountered in attempting to prepare astrocytes for XRMA.Tissue cultures of astrocytes from newborn C57 mice or Sprague Dawley rats were prepared and cultured by standard techniques, usually in T25 flasks, except as noted differently on Cytodex beads or on gelatin. After different preparative procedures, all samples were frozen on brass pins in liquid propane, stored in liquid nitrogen, cryosectioned (0.1 μm), freeze dried, and microanalyzed as previously reported.

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