MICRON-CT USING PIXE WITH MICRO-BEAMS

2005 ◽  
Vol 15 (03n04) ◽  
pp. 111-123 ◽  
Author(s):  
K. ISHII ◽  
S. MATSUYAMA ◽  
H. YAMAZAKI ◽  
Y. WATANABE ◽  
T. YAMAGUCHI ◽  
...  
Keyword(s):  
Small Diameter ◽  
Ccd Camera ◽  
X Rays ◽  
Image Size ◽  
Cross Sectional ◽  
3D Images ◽  
Element Size ◽  
Wide Range ◽  
Transmission Data

We developed a micron-CT consisting of micro-beam system and X-ray CCD camera (Hamamatsu photonics C8800X), whose element size is 8μ m ×8μ m and a total number of image elements 1000×1000 gives an image size of 8 mm ×8 mm . The sample is placed in a tube of a small diameter, which is rotated by a stepping motor. The transmission data through the sample are taken with characteristic Ti - K -X-rays (4.558 keV) produced by 3MeV proton and α particle micro-beams. After image reconstruction using an iteration method, 3D-images of small objects namely, hair and small ants were obtained with a spatial resolution of ~5μm. It is expected that our micron-CT can provide cross sectional images of in-vivo cellular samples with high resolution and can be applied to a wide range of research in biology and medicine.

Renal contrast microangiography with synchrotron radiation: a novel method for visualizing structures within nephrons in vivo

2016 ◽  
Vol 58 (4) ◽  
pp. 505-510 ◽  
Author(s):  
Ken Miya ◽  
Shonosuke Matsushita ◽  
Kazuyuki Hyodo ◽  
Chiho Tokunaga ◽  
Hiroaki Sakamoto ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Ccd Camera ◽  
Average Diameter ◽  
Blocking Agent ◽  
Neuromuscular Blocking ◽  
Proximal Tubules ◽  
X Rays ◽  
Renal Microcirculation ◽  
Male Wistar Rats

Background No non-invasive method of observing renal microcirculation in vivo has been established as yet. Although angiography is considered to be ideally suited for the purpose, conventional X-rays cannot be used to image structures smaller than 100 µm. Purpose To develop a method for visualizing the renal arterioles, glomeruli, and proximal tubules of rats in vivo making use of synchrotron radiation. Material and Methods Male Wistar rats were anesthetized, and a catheter was inserted via laparotomy into the abdominal aorta with its tip placed above the renal arteries. The rats were paralyzed with a neuromuscular blocking agent and mechanically ventilated. An inorganic iodine contrast medium was injected via the catheter. The SR derived X-rays transmitted through the subjects were recorded with a CCD camera. Two-dimensional images with a pixel size of 9 µm were obtained. The exposure time was fixed at 50 ms, with a maximum acquisition rate of three images/s. Results Renal arterioles as small as 18 µm in diameter, glomeruli with an average diameter of 173 ± 21 µm, as well as proximal tubules, were clearly visualized. In addition, glomerular density at the peripheral renal cortex was measurable. Conclusion Rat renal microcirculation could be successfully observed in real-time, without exteriorization of the kidney in this study.

In Vivo X-Ray Fluorescence of Lead and Other Toxic Trace Elements

1994 ◽  
Vol 38 ◽  
pp. 563-572 ◽  
Author(s):  
David R. Chettle
Keyword(s):  
Blood Lead ◽  
Data Sets ◽  
X Rays ◽  
Cross Sectional ◽  
X Ray ◽  
Fluorescence Measurements ◽  
Bone Lead ◽  
Γ Rays ◽  
Source Excitation

Abstract The first in vivo x-ray fluorescence measurements of lead in bone used y-rays from a 57Co source to excite Pb K x-rays. Later systems used γ-rays from 109Cd to excite Pb K x-rays or polarized x-rays to excite Pb L x-rays. All three approaches involve an extremely low effective dose to the subject. Of the two K x-ray techniques, 109Cd is more precise and more flexible in choice of measurement site. Pb L x-ray fluorescence (L-XRF) effectively samples lead at bone surfaces, whereas Pb K x-ray fluorescence (K-XRF) samples through the bulk of a bone. Both the polarized L-XRF and 109Cd K-XRF achieve similar precision. Renal mercury has recently been determined using a polarized x-ray source. Both renal and hepatic cadmium can be measured using polarized x-rays in conjunction with a Si(Li) detector. Platinum and gold have been measured both by radioisotopic source excitation and by using polarized x-rays, but the latter is to be preferred. Applications of Pb K-XRF have shown that measured bone lead relates strongly to cumulative lead exposure. Secondly, biological half lives of lead in different bone types have been estimated from limited longitudinal data sets and from some cross sectional surveys. Thirdly, the effect of hone lead as an endogenous source of lead has been demonstrated and it has been shown that a majority of circulating blood lead can be mobilized from bone, rather than deriving from new exposure, in some retired lead workers.

IN-VIVO ELEMENTAL ANALYSIS BY PIXE-μ-CT

2007 ◽  
Vol 17 (01n02) ◽  
pp. 41-46 ◽  
Author(s):  
Y. KAWAMURA ◽  
K. ISHII ◽  
H. YAMAZAKI ◽  
S. MATSUYAMA ◽  
Y. KIKUCHI ◽  
...  
Keyword(s):  
High Resolution ◽  
Absorption Edge ◽  
Ion Beam ◽  
Projection Data ◽  
Elemental Distribution ◽  
X Rays ◽  
Ct Reconstruction ◽  
3D Images ◽  
X Ray

We have developed “micron-CT”, using micro-PIXE for in-vivo imaging. This system comprises an X-ray CCD camera (Hamamatsu photonics C8800X9) with high resolution (pixel size: 8×8 μm 2, number of pixels: 1000×1000) and an X-ray-point-source with a spot size of 1.5×1.5 μm 2 which is generated by irradiation of a microbeam on a pure metal target. Thus we can acquire projection data with high resolution. The sample is placed in a small diameter tube and is rotated by a stepping motor. The 3D images were reconstructed from the obtained projection data by using cone-beam CT reconstruction algorithm. X-ray spectra produced by heavy charged particle bombardment, exhibit a much smaller continuous background compared to electron bombardment. Therefore, X-rays produced by ion beam can be used as a monochromatic and low energy X-ray source. The feature is very effective to investigate small insects. Moreover we can get elemental distribution image of object by choosing appropriate characteristic X-rays corresponding to the absorption edge. On the other hand, the conventional X-ray CT, in which continuous X-rays are used, provides images of the electron density in the object. Using this system, we were able to get 3D images of a living ant's head with 6 μm spatial resolution. By using Fe - K -X-rays (6.40 keV) and Co - K -X-rays (6.93 keV), we can investigate the 3D distribution of Mn ( K -absorption edge = 6.54 keV) in an ant's head.

In Vivo Measurement of the Elasticity and Diameter of the Femoral Artery

1985 ◽  
Vol 26 (6) ◽  
pp. 723-726 ◽  
Author(s):  
T. Christensen ◽  
B. Neubauer
Keyword(s):  
Medical Students ◽  
Femoral Artery ◽  
Significant Positive Correlation ◽  
Significant Rise ◽  
Sectional Area ◽  
Cross Sectional ◽  
In Vivo Measurement ◽  
Individual Variations ◽  
Wide Range

The diameter and the elastic properties of the femoral artery were investigated by means of ultrasound M-mode. The nature of individual variations was determined in 27 medical students at the age of 21–23 years. A significant positive correlation was found between height and increasing arterial cross sectional area. The influence of age upon arterial luminal size and elasticity was estimated in a group of 43 persons with a wide range of age. There was a significant rise in stiffness proportional to age, but none in luminal size.

In vitro models of the human microbiota and microbiome

2017 ◽  
Vol 1 (4) ◽  
pp. 373-384 ◽  
Author(s):  
Julie A.K. McDonald
Keyword(s):  
Microbial Communities ◽  
Longitudinal Studies ◽  
New Technologies ◽  
Disease Status ◽  
Mechanistic Studies ◽  
Cross Sectional ◽  
Wide Range ◽  
Gut Fermentation

Gut microbiome studies have been gaining popularity over the years, especially with the development of new technologies (e.g. metataxonomics, metagenomics, metatranscriptomics, and metabonomics) that makes it easier for researchers to characterize the composition and functionality of these complex microbial communities. The goal of these studies is to identify a microorganism, group of microbes, or microbial metabolite which correlates with a disease state (e.g. inflammatory bowel disease, colorectal cancer, and obesity). Many of these are cross-sectional studies, where fecal samples from a group of diseased individuals are compared with those from a group of healthy individuals at a single time point. However, there are a wide range of variables that can affect the gut microbiota of humans which make mechanistic studies challenging. Longitudinal studies are required for research to more reliably correlate interventions or disease status to microbiota composition and functionality. However, longitudinal studies in humans and animals are difficult, expensive, and time-consuming. This review will discuss in vitro gut fermentation models and how they can be used to perform longitudinal studies that complement in vivo microbiome studies. Gut fermentation models support the growth of stable, reproducible, and diverse microbial communities in a tightly controlled environment set to mimic the conditions microbes encounter in the gastrointestinal tract. Gut fermentation models will make it easier for researchers to perform mechanistic studies and aid in the development of novel treatments that are both targeted and maintained over time.

Development of biliary stent applying the antibacterial activity of silver: A literature review

2021 ◽  
Vol 32 (2) ◽  
pp. 63-71
Author(s):  
Akane Yamabe ◽  
Atsushi Irisawa ◽  
Yasuhito Kunogi ◽  
Ken Kashima ◽  
Kazunori Nagashima ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Low Cost ◽  
Small Diameter ◽  
Silver Ions ◽  
Silver Coating ◽  
Biliary Stents ◽  
Stent Patency ◽  
Plastic Stent ◽  
Wide Range

BACKGROUND: Endoscopic transpapillary stenting is commonly performed in patients with obstructive jaundice caused by a biliary stricture. Although the plastic stent (PS) is widely used for biliary drainage because of the low-cost and easy procedure, patency is short after placement in the bile duct because of the small diameter. Dysfunction of PS is primarily caused by biliary sludge that forms as a result of bacterial adhesion and subsequent biofilm formation on the inner surface of the stent. It is well known that silver ions have excellent antibacterial activity against a wide range of microorganisms. OBJECTIVE: This review provides an overview and perspective of the significance of silver-coated biliary stents. METHODS: We collected literature regarding silver-coated biliary stents, reviewed the current research/development status and discussed their possible usefulness. RESULTS: To date, several in vivo/vitro studies evaluated the patency of silver-blended or silver-coated biliary stents. These studies suggested that the silver coating on a PS was likely to prolong the patency period. CONCLUSION: The development of biliary stents using silver is expected to prolong stent patency and prevent frequent stent replacement.

X-ray micro tomography in the scanning electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 106-107 ◽  
Author(s):  
W. Brünger
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Target Surface ◽  
The Body ◽  
X Rays ◽  
Cross Sectional ◽  
X Ray ◽  
Micro Tomography ◽  
Scanning Electron

Reconstructive tomography is a new technique in diagnostic radiology for imaging cross-sectional planes of the human body /1/. A collimated beam of X-rays is scanned through a thin slice of the body and the transmitted intensity is recorded by a detector giving a linear shadow graph or projection (see fig. 1). Many of these projections at different angles are used to reconstruct the body-layer, usually with the aid of a computer. The picture element size of present tomographic scanners is approximately 1.1 mm2.Micro tomography can be realized using the very fine X-ray source generated by the focused electron beam of a scanning electron microscope (see fig. 2). The translation of the X-ray source is done by a line scan of the electron beam on a polished target surface /2/. Projections at different angles are produced by rotating the object.During the registration of a single scan the electron beam is deflected in one direction only, while both deflections are operating in the display tube.

Measurements in 3D images

1991 ◽  
Vol 49 ◽  
pp. 408-409
Author(s):  
John C. Russ
Keyword(s):  
Three Dimensional ◽  
Image Plane ◽  
X Rays ◽  
Traditional Use ◽  
3D Images ◽  
Confocal Scanning Laser Microscope ◽  
Hard Materials ◽  
Depth Direction ◽  
Confocal Scanning ◽  
Confocal Scanning Laser

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.

A Color Coded STEM/SEM Image Storage System

1981 ◽  
Vol 39 ◽  
pp. 272-273
Author(s):  
Y. Kokubo ◽  
W. H. Hardy ◽  
J. Dance ◽  
K. Jones
Keyword(s):  
Image Processing ◽  
Electron Beam ◽  
Storage System ◽  
Particle Analysis ◽  
Specific Information ◽  
X Rays ◽  
Sem Image ◽  
Backscattered Electrons ◽  
Wide Range ◽  
Scanning Electron

A color coded digital image processing is accomplished by using JEM100CX TEM SCAN and ORTEC’s LSI-11 computer based multi-channel analyzer (EEDS-II-System III) for image analysis and display. Color coding of the recorded image enables enhanced visualization of the image using mathematical techniques such as compression, gray scale expansion, gamma-processing, filtering, etc., without subjecting the sample to further electron beam irradiation once images have been stored in the memory.The powerful combination between a scanning electron microscope and computer is starting to be widely used 1) - 4) for the purpose of image processing and particle analysis. Especially, in scanning electron microscopy it is possible to get all information resulting from the interactions between the electron beam and specimen materials, by using different detectors for signals such as secondary electron, backscattered electrons, elastic scattered electrons, inelastic scattered electrons, un-scattered electrons, X-rays, etc., each of which contains specific information arising from their physical origin, study of a wide range of effects becomes possible.

Characterization of Rh/Si multilayer structure by HREM and HAADF

1992 ◽  
Vol 50 (1) ◽  
pp. 122-123
Author(s):  
Y. Cheng ◽  
J. Liu ◽  
M.B. Stearns ◽  
D.G. Steams
Keyword(s):  
Normal Incidence ◽  
High Resolution Electron Microscopy ◽  
X Rays ◽  
Beam Direction ◽  
Cross Sectional ◽  
Optical Elements ◽  
Resolution Electron ◽  
Point To Point ◽  
Better Than

The Rh/Si multilayer (ML) thin films are promising optical elements for soft x-rays since they have a calculated normal incidence reflectivity of ∼60% at a x-ray wavelength of ∼13 nm. However, a reflectivity of only 28% has been attained to date for ML fabricated by dc magnetron sputtering. In order to determine the cause of this degraded reflectivity the microstructure of this ML was examined on cross-sectional specimens with two high-resolution electron microscopy (HREM and HAADF) techniques.Cross-sectional specimens were made from an as-prepared ML sample and from the same ML annealed at 298 °C for 1 and 100 hours. The specimens were imaged using a JEM-4000EX TEM operating at 400 kV with a point-to-point resolution of better than 0.17 nm. The specimens were viewed along Si [110] projection of the substrate, with the (001) Si surface plane parallel to the beam direction.

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