Dynamic three-dimensional observation of corner turning in LX-17 with flash x-rays

Three-dimensional (3D) images consisting of arrays of voxels can now be routinely obtained from several different types of microscopes. These include both the transmission and emission modes of the confocal scanning laser microscope (but not its most common reflection mode), the secondary ion mass spectrometer, and computed tomography using electrons, X-rays or other signals. Compared to the traditional use of serial sectioning (which includes sequential polishing of hard materials), these newer techniques eliminate difficulties of alignment of slices, and maintain uniform resolution in the depth direction. However, the resolution in the z-direction may be different from that within each image plane, which makes the voxels non-cubic and creates some difficulties for subsequent analysis.

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Is Micro X-ray Computer Tomography a Suitable Non-Destructive Method for the Characterisation of Dental Materials?

Polymers ◽

10.3390/polym13081271 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1271

Author(s):

Andreas Koenig ◽

Leonie Schmohl ◽

Johannes Scheffler ◽

Florian Fuchs ◽

Michaela Schulz-Siegmund ◽

...

Keyword(s):

Flexural Strength ◽

Computer Tomography ◽

Mechanical Performance ◽

Dental Materials ◽

Three Dimensional ◽

X Rays ◽

Scanning Calorimetry ◽

X Ray ◽

Multiple Measurements ◽

High Doses

The aim of the study was to investigate the effect of X-rays used in micro X-ray computer tomography (µXCT) on the mechanical performance and microstructure of a variety of dental materials. Standardised bending beams (2 × 2 × 25 mm3) were forwarded to irradiation with an industrial tomograph. Using three-dimensional datasets, the porosity of the materials was quantified and flexural strength was investigated prior to and after irradiation. The thermal properties of irradiated and unirradiated materials were analysed and compared by means of differential scanning calorimetry (DSC). Single µXCT measurements led to a significant decrease in flexural strength of polycarbonate with acrylnitril-butadien-styrol (PC-ABS). No significant influence in flexural strength was identified for resin-based composites (RBCs), poly(methyl methacrylate) (PMMA), and zinc phosphate cement (HAR) after a single irradiation by measurement. However, DSC results suggest that changes in the microstructure of PMMA are possible with increasing radiation doses (multiple measurements, longer measurements, higher output power from the X-ray tube). In summary, it must be assumed that X-ray radiation during µXCT measurement at high doses can lead to changes in the structure and properties of certain polymers.

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Visualizing Fluid Flows With X-Rays

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2007-37023 ◽

2007 ◽

Cited By ~ 4

Author(s):

Theodore J. Heindel ◽

Terrence C. Jensen ◽

Joseph N. Gray

Keyword(s):

Computed Tomography ◽

Flow Visualization ◽

Three Dimensional ◽

Fluid Flows ◽

X Rays ◽

Radiographic Images ◽

Optical Access ◽

X Ray ◽

X Ray Computed ◽

Density Map

There are several methods available to visualize fluid flows when one has optical access. However, when optical access is limited to near the boundaries or not available at all, alternative visualization methods are required. This paper will describe flow visualization using an X-ray system that is capable of digital X-ray radiography, digital X-ray stereography, and digital X-ray computed tomography (CT). The unique X-ray flow visualization facility will be briefly described, and then flow visualization of various systems will be shown. Radiographs provide a two-dimensional density map of a three dimensional process or object. Radiographic images of various multiphase flows will be presented. When two X-ray sources and detectors simultaneously acquire images of the same process or object from different orientations, stereographic imaging can be completed; this type of imaging will be demonstrated by trickling water through packed columns and by absorbing water in a porous medium. Finally, local time-averaged phase distributions can be determined from X-ray computed tomography (CT) imaging, and this will be shown by comparing CT images from two different gas-liquid sparged columns.

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Recent Developments In Monochromatic Microprobe X-Ray Fluorescence (MMXRF)

Microscopy and Microanalysis ◽

10.1017/s1431927600022017 ◽

1998 ◽

Vol 4 (S2) ◽

pp. 378-379

Author(s):

Z. W. Chen ◽

D. B. Wittry

Keyword(s):

Materials Science ◽

High Vacuum ◽

Three Dimensional ◽

High Sensitivity ◽

X Rays ◽

Fluorescence Excitation ◽

X Ray ◽

Quantitative Microanalysis ◽

Recent Developments ◽

Fifth Order

A monochromatic x-ray microprobe based on a laboratory source has recently been developed in our laboratory and used for fluorescence excitation. This technique provides high sensitivity (ppm to ppb), nondestructive, quantitative microanalysis with minimum sample preparation and does not require a high vacuum specimen chamber. It is expected that this technique (MMXRF) will have important applications in materials science, geological sciences and biological science.Three-dimensional focusing of x-rays can be obtained by using diffraction from doubly curved crystals. In our MMXRF setup, a small x-ray source was produced by the bombardment of a selected target with a focused electron beam and a toroidal mica diffractor with Johann pointfocusing geometry was used to focus characteristic x-rays from the source. In the previous work ∼ 108 photons/s were obtained in a Cu Kα probe of 75 μm × 43 μm in the specimen plane using the fifth order reflection of the (002) planes of mica.

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Bone-mounted Miniature Robotic Guidance for Pedicle Screw and Translaminar Facet Screw Placement: Part 2—Evaluation of System Accuracy

Operative Neurosurgery ◽

10.1227/01.neu.0000249257.16912.aa ◽

2007 ◽

Vol 60 (suppl_2) ◽

pp. ONS-129-ONS-139 ◽

Cited By ~ 23

Author(s):

Daisuke Togawa ◽

Mark M. Kayanja ◽

Mary K. Reinhardt ◽

Moshe Shoham ◽

Alin Balter ◽

...

Keyword(s):

Minimally Invasive ◽

Three Dimensional ◽

Contralateral Side ◽

X Rays ◽

Average Deviation ◽

Computed Tomographic ◽

Entry Points ◽

External Frame ◽

K Wires ◽

Preoperative Plan

Abstract Objective: To evaluate the accuracy of a novel bone-mounted miniature robotic system for percutaneous placement of pedicle and translaminar facet screws. Methods: Thirty-five spinal levels in 10 cadavers were instrumented. Each cadaver's entire torso was scanned before the procedure. Surgeons planned optimal entry points and trajectories for screws on reconstructed three-dimensional virtual x-rays of each vertebra. Either a clamp or a minimally invasive external frame was attached to the bony anatomy. Anteroposterior and lateral fluoroscopic images using targeting devices were obtained and automatically registered with the virtual x-rays of each vertebra generated from the computed tomographic scan obtained before the procedure. A miniature robot was mounted onto the clamp and external frame and the system controlled the robot's motions to align the cannulated drill guide along the planned trajectory. A drill bit was introduced through the cannulated guide and a hole was drilled through the cortex. Then, K-wires were introduced and advanced through the same cannulated guide and left inside the cadaver. The cadavers were scanned with computed tomography after the procedure and the system's accuracy was evaluated in three planes, comparing K-wire positions with the preoperative plan. A total of fifty-five procedures were evaluated. Results: Twenty-nine of 32 K-wires and all four screws were placed with less than 1.5 mm of deviation; average deviation was 0.87 ± 0.63 mm (range, 0-1.7 mm) from the preoperative plan in this group. Sixteen of 19 K-wires were placed with less than 1.5 mm of deviation. There was one broken and one bent K-wire. Another K-wire was misplaced because of collision with the previously placed wire on the contralateral side of the same vertebra because of a mistake in planning, resulting in a 6.5-mm deviation. When this case was excluded, average deviation was 0.82 ± 0.65 mm (range, 0-1.5 mm). Conclusion: These results verify the system's accuracy and support its use for minimally invasive spine surgery in selected patients.

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A Novel Technique to Assess Rotational Deformities in Lower Extremities

10.21203/rs.3.rs-115250/v1 ◽

2020 ◽

Author(s):

Peyman Bakhshayesh ◽

Ugwunna Ihediwa ◽

Sukha Sandher ◽

Alexandros Vris ◽

Nima Heidari ◽

...

Keyword(s):

Moving Objects ◽

Sagittal Plane ◽

Three Dimensional ◽

Contralateral Side ◽

Ct Images ◽

New Technique ◽

X Rays ◽

Digital Technique ◽

The Right ◽

Im Nailing

Abstract Introduction: Rotational deformities following IM nailing of tibia has a reported incidence of as high as 20%. Common techniques to measure deformities following IM nailing of tibia are either based on clinical assessment, plain X-rays or CT-scan comparing the treated leg with the uninjured contralateral side. All these techniques are based on examiners manual calculation inherently subject to bias. Following our previous rigorous motion analysis and symmetry studies on hemi pelvises, femurs and orthopaedic implants, we aimed to introduce a novel fully digital technique to measure rotational deformities in the lower legs.Material and Methods: Following formal institutional approval from the Imperial College, CT images of 10 pairs of human lower legs were retrieved. Images were anonymized and uploaded to a research server. Three dimensional CT images of the lower legs were bilaterally reconstructed. The mirrored images of the left side were merged with the right side proximally as stationary and distally as moving objects. Discrepancies in translation and rotation were automatically calculated.Results: Our study population had a mean age of 54 ± 20 years. There were six males and four females. We observed a greater variation in translation (mm) of Centre of Mass (COM) in sagittal plane (CI: -2.959--.292) which was also presented as rotational difference alongside the antero-posterior direction or Y axis (CI: .370-1.035). In other word the right lower legs in our study were more likely to be in varus compared to the left side. However, there were no statistically significant differences in coronal or axial planes.Conclusion: Using our proposed fully digital technique we found that lower legs of the human adults were symmetrical in axial and coronal plane. We found sagittal plane differences which need further addressing in future using bigger sample size. Our novel recommended technique is fully digital and commercially available. This new technique can be useful in clinical practice addressing rotational deformities following orthopaedic surgical intervention. This new technique can substitute the previously introduced techniques.

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Hard X-ray polarizer to enable simultaneous three-dimensional nanoscale imaging of magnetic structure and lattice strain

Journal of Synchrotron Radiation ◽

10.1107/s1600577516009632 ◽

2016 ◽

Vol 23 (5) ◽

pp. 1210-1215 ◽

Cited By ~ 3

Author(s):

Jonathan Logan ◽

Ross Harder ◽

Luxi Li ◽

Daniel Haskel ◽

Pice Chen ◽

...

Keyword(s):

Magnetic Circular Dichroism ◽

Three Dimensional ◽

Control Sample ◽

Magnetic Ordering ◽

X Rays ◽

Diffractive Imaging ◽

X Ray ◽

Coherent Diffractive Imaging ◽

Diffraction Patterns ◽

A New Technique

Recent progress in the development of dichroic Bragg coherent diffractive imaging, a new technique for simultaneous three-dimensional imaging of strain and magnetization at the nanoscale, is reported. This progress includes the installation of a diamond X-ray phase retarder at beamline 34-ID-C of the Advanced Photon Source. The performance of the phase retarder for tuning X-ray polarization is demonstrated with temperature-dependent X-ray magnetic circular dichroism measurements on a gadolinium foil in transmission and on a Gd5Si2Ge2crystal in diffraction geometry with a partially coherent, focused X-ray beam. Feasibility tests for dichroic Bragg coherent diffractive imaging are presented. These tests include (1) using conventional Bragg coherent diffractive imaging to determine whether the phase retarder introduces aberrations using a nonmagnetic gold nanocrystal as a control sample, and (2) collecting coherent diffraction patterns of a magnetic Gd5Si2Ge2nanocrystal with left- and right-circularly polarized X-rays. Future applications of dichroic Bragg coherent diffractive imaging for the correlation of strain and lattice defects with magnetic ordering and inhomogeneities are considered.

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Synchrotron radiation X-ray tomographic microscopy (SRXTM) of brachiopod shell interiors for taxonomy: Preliminary report

Geoloski anali Balkanskog poluostrva ◽

10.2298/gabp1071109m ◽

2010 ◽

pp. 109-117 ◽

Cited By ~ 6

Author(s):

Neda Motchurova-Dekova ◽

David Harper

Keyword(s):

Synchrotron Radiation ◽

Three Dimensional ◽

X Rays ◽

X Ray ◽

Fine Grained ◽

Internal Structures ◽

Efficient Alternative ◽

Micro Tomography ◽

Light Beams ◽

Non Destructive

Synchrotron radiation X-ray tomographic microscopy (SRXTM) is a non-destructive technique for the investigation and visualization of the internal features of solid opaque objects, which allows reconstruction of a complete three-dimensional image of internal structures by recording of the differences in the effects on the passage of waves of energy reacting with those structures. Contrary to X-rays, produced in a conventional X-ray tube, the intense synchrotron light beams are sharply focused like a laser beam. We report encouraging results from the use of SRXTM for purely taxonomic purposes in brachiopods: an attempt to find a non-destructive and more efficient alternative to serial sectioning and several other methods of dissection together with the non-destructive method of X-ray computerised micro-tomography. Two brachiopod samples were investigated using SRXTM. In ?Rhynchonella? flustracea it was possible to visualise the 3D shape of the crura and dental plates. In Terebratulina imbricata it was possible to reveal the form of the brachidium. It is encouraging that we have obtained such promising results using SRXTM with our very first two fortuitous samples, which had respectively fine-grained limestone and marl as infilling sediment, in contrast to the discouraging results communicated to us by some colleagues who have tested specimens with such infillings using X-ray micro-tomography. In future the holotypes, rare museum specimens or delicate Recent material may be preferentially subjected to this mode of analysis.

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Management of two-level proximal femoral fractures

BMJ Case Reports ◽

10.1136/bcr-2020-240684 ◽

2021 ◽

Vol 14 (5) ◽

pp. e240684

Author(s):

Thom Pauline Maria Johannes Vluggen ◽

Raoul van Vugt ◽

Bert Boonen ◽

Mark Hendrik Franciscus Keulen

Keyword(s):

Three Dimensional ◽

Femoral Fractures ◽

Ground Level ◽

Proximal Femoral Fracture ◽

Fracture Pattern ◽

Primary Osteoporosis ◽

X Rays ◽

Greater Trochanter ◽

Subsequent Increase ◽

Adequate Treatment

We present the case of an 82-year-old female, who experienced a ground-level fall on the trochanter of the right femur. X-rays showed a proximal femoral fracture (PFF) with an unclear and unusual fracture pattern. Three-dimensional CT images were obtained and showed a displaced femoral neck fracture and ipsilateral fracture of the greater trochanter. Our patient underwent unipolar hemiarthroplasty and fixation of the greater trochanter with a hook plate and cable grip. At 11 months, functional outcomes, patient satisfaction and quality of life were excellent. Primary osteoporosis was diagnosed and treatment with bisphosphonates was initiated.Two-level PFFs are rare and complex. Due to ageing and a subsequent increase in osteoporosis, numbers of PFFs with complex fracture patterns might increase in the future. Adequate treatment and early prevention of osteoporosis are key to reduce this risk and lower the overall burden. Surgical treatment should be patient-tailored and focus on minimising the risk of complications and reinterventions.

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Diffraction

Outline of Crystallography for Biologists ◽

10.1093/oso/9780198510512.003.0008 ◽

2002 ◽

Author(s):

David Blow

Keyword(s):

Red Light ◽

Three Dimensional ◽

Three Dimensions ◽

X Rays ◽

X Ray ◽

Original Direction ◽

Computational Procedures ◽

Scattering Material ◽

Opaque Object ◽

Diffraction Effects

Diffraction refers to the effects observed when light is scattered into directions other than the original direction of the light, without change of wavelength. An X-ray photon may interact with an electron and set the electron oscillating with the X-ray frequency. The oscillating electron may radiate an X-ray photon of the same wavelength, in a random direction, when it returns to its unexcited state. Other processes may also occur, akin to fluorescence, which emit X-rays of longer wavelengths, but these processes do not give diffraction effects. Just as we see a red card because red light is scattered off the card into our eyes, objects are observed with X-rays because an illuminating X-ray beam is scattered into the X-ray detector. Our eye can analyse details of the card because its lens forms an image on the retina. Since no X-ray lens is available, the scattered X-ray beam cannot be converted directly into an image. Indirect computational procedures have to be used instead. X-rays are penetrating radiation, and can be scattered from electrons throughout the whole scattering object, while light only shows the external shape of an opaque object like a red card. This allows X-rays to provide a truly three-dimensional image. When X-rays pass near an atom, only a tiny fraction of them is scattered: most of the X-rays pass further into the object, and usually most of them come straight out the other side of the whole object. In forming an image, these ‘straight through’ X-rays tell us nothing about the structure, and they are usually captured by a beam stop and ignored. This chapter begins by explaining that the diffraction of light or X-rays can provide a precise physical realization of Fourier’s method of analysing a regularly repeating function. This method may be used to study regularly repeating distributions of scattering material. Beginning in one dimension, examples will be used to bring out some fundamental features of diffraction analysis. Graphic examples of two-dimensional diffraction provide further demonstrations. Although the analysis in three dimensions depends on exactly the same principles, diffraction by a three-dimensional crystal raises additional complications.

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