scholarly journals Targeting Specific Sites in Biological Systems with Synchrotron X-Ray Microbeams for Radiobiological Studies at the Photon Factory

2020 ◽  
Vol 4 (1) ◽  
pp. 2 ◽  
Author(s):  
Akinari Yokoya ◽  
Noriko Usami
Keyword(s):  
Low Dose ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Biological Effects ◽  
Radiation Risk ◽  
Genetic Alterations ◽  
Culture Technique ◽  
Beam Size ◽  
X Ray ◽  
Photon Factory

X-ray microbeams have been used to explore radiobiological effects induced by targeting a specific site in living systems. Synchrotron radiation from the Photon Factory, Japan, with high brilliance and highly parallel directionality is a source suitable for delivering a particular beam size or shape, which can be changed according to target morphology by using a simple metal slit system (beam size from 5 μm to several millimeters). Studies have examined the non-targeted effects, called bystander cellular responses, which are thought to be fundamental mechanisms of low-dose or low-dose-rate effects in practical radiation risk research. Narrow microbeams several tens of micrometers or less in their size targeted both the cell nucleus and the cytoplasm. Our method combined with live-cell imaging techniques has challenged the traditional radiobiological dogma that DNA damage is the only major cause of radiation-induced genetic alterations and is gradually revealing the role of organelles, such as mitochondria, in these biological effects. Furthermore, three-dimensionally cultured cell systems have been used as microbeam targets to mimic organs. Combining the spatial fractionation of X-ray microbeams and a unique ex vivo testes organ culture technique revealed that the tissue-sparing effect was induced in response to the non-uniform radiation fields. Spatially fractionated X-ray beams may be a promising tool in clinical radiation therapy.

scholarly journals Optical to Planar X-ray Mouse Image Mapping in Preclinical Nuclear Medicine Using Conditional Adversarial Networks

2021 ◽  
Vol 7 (12) ◽  
pp. 262
Author(s):  
Eleftherios Fysikopoulos ◽  
Maritina Rouchota ◽  
Vasilis Eleftheriadis ◽  
Christina-Anna Gatsiou ◽  
Irinaios Pilatis ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Performance Metrics ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Similarity Index ◽  
Zero Point ◽  
Ground Truth ◽  
Generative Adversarial Network ◽  
X Ray ◽  
Photographic Images

In the current work, a pix2pix conditional generative adversarial network has been evaluated as a potential solution for generating adequately accurate synthesized morphological X-ray images by translating standard photographic images of mice. Such an approach will benefit 2D functional molecular imaging techniques, such as planar radioisotope and/or fluorescence/bioluminescence imaging, by providing high-resolution information for anatomical mapping, but not for diagnosis, using conventional photographic sensors. Planar functional imaging offers an efficient alternative to biodistribution ex vivo studies and/or 3D high-end molecular imaging systems since it can be effectively used to track new tracers and study the accumulation from zero point in time post-injection. The superimposition of functional information with an artificially produced X-ray image may enhance overall image information in such systems without added complexity and cost. The network has been trained in 700 input (photography)/ground truth (X-ray) paired mouse images and evaluated using a test dataset composed of 80 photographic images and 80 ground truth X-ray images. Performance metrics such as peak signal-to-noise ratio (PSNR), structural similarity index measure (SSIM) and Fréchet inception distance (FID) were used to quantitatively evaluate the proposed approach in the acquired dataset.

Bone mineral density assessment using the EOS® low-dose X-ray device: A feasibility study

2008 ◽  
Vol 222 (8) ◽  
pp. 1263-1271 ◽  
Author(s):  
E Sapin ◽  
K Briot ◽  
S Kolta ◽  
P Gravel ◽  
W Skalli ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Coefficient Of Variation ◽  
Low Dose ◽  
Ex Vivo ◽  
Three Dimensional ◽  
Mineral Density ◽  
X Ray ◽  
Error Coefficient ◽  
Eos System

To predict bone strength in the case of osteoporosis, it could be a real benefit to assess the three-dimensional (3D) geometry and the bone mineral density (BMD) with a single low-dose X-ray device, such as the EOS system (Biospace Med, Paris, France). EOS 3D reconstructions of the spine have already been validated. Thus, this study aims at evaluating the accuracy of this low-dose system as a densitometer first ex vivo. The European Spine Phantom (ESP) (number 129) was scanned ten times using both the EOS and a Hologic device (Hologic, Inc., Massachusetts, USA). Accuracy was given by the sum of the systematic error (difference between BMDs assessed and true values given by the phantom manufacturer) and the random error (coefficient of variation). EOS BMDs and Hologic BMDs of 41 ex-vivo vertebrae were calculated and compared. The reproducibility of the method evaluating the EOS BMD was assessed giving the coefficient of variation of three measurements of the 41 vertebrae. The accuracy of the EOS system is below 5.2 per cent, versus 7.2 per cent for the Hologic system in the same conditions. EOS BMDs are significantly higher than Hologic BMDs, but they are strongly correlated. The reproducibility of the method of assessment is equal to 0.95 per cent. The EOS system is accurate for ex-vivo BMD assessments, which is promising regarding the use of this new system to predict vertebral strength.

Tagging for Capsule Endoscopy Localization

2011 ◽  
Vol 254 ◽  
pp. 99-102
Author(s):  
Rui Qi Lim ◽  
Riyas Katayan ◽  
Shwe Sin Win ◽  
Kripesh Vaidyanathan
Keyword(s):  
Capsule Endoscopy ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Region Of Interest ◽  
Medical Procedure ◽  
Position Information ◽  
X Ray ◽  
Imaging Result ◽  
Animal Trials ◽  
X Ray Imaging

Capsule endoscopy is a medical procedure to painlessly image the Gastro intestinal tract for the diagnosis of small intestine mucosa. Present capsule endoscopy does not comprise an effective method to localize and tag the abnormalities in gastrointestinal tract during the image diagnosis. The major constraint for developing an addition function to the existing capsule is the limited package space. In this paper, we propose a novel method for the effective localization of site of interest by incorporating a miniaturized tagging module inside the capsule. The tagging module release a micro tag which embed into the region of interest upon activation. This micro tag can be detected through radiographic imaging techniques like X-ray imaging. Embedded micro tag provides valuable position information of the site of interest to facilitate further diagnosis. This paper will present the ex-vivo animal trials and the x-ray imaging result of the tagging module.

scholarly journals X-ray in-line holography and holotomography at the NanoMAX beamline

2022 ◽  
Vol 29 (1) ◽  
Author(s):  
Sebastian Kalbfleisch ◽  
Yuhe Zhang ◽  
Maik Kahnt ◽  
Khachiwan Buakor ◽  
Max Langer ◽  
...  
Keyword(s):  
Electron Density ◽  
Low Dose ◽  
Focal Spot ◽  
Chemical Elements ◽  
Imaging Techniques ◽  
High Sensitivity ◽  
X Ray ◽  
X Ray Imaging ◽  
Dose Imaging ◽  
2D And 3D

Coherent X-ray imaging techniques, such as in-line holography, exploit the high brilliance provided by diffraction-limited storage rings to perform imaging sensitive to the electron density through contrast due to the phase shift, rather than conventional attenuation contrast. Thus, coherent X-ray imaging techniques enable high-sensitivity and low-dose imaging, especially for low-atomic-number (Z) chemical elements and materials with similar attenuation contrast. Here, the first implementation of in-line holography at the NanoMAX beamline is presented, which benefits from the exceptional focusing capabilities and the high brilliance provided by MAX IV, the first operational diffraction-limited storage ring up to approximately 300 eV. It is demonstrated that in-line holography at NanoMAX can provide 2D diffraction-limited images, where the achievable resolution is only limited by the 70 nm focal spot at 13 keV X-ray energy. Also, the 3D capabilities of this instrument are demonstrated by performing holotomography on a chalk sample at a mesoscale resolution of around 155 nm. It is foreseen that in-line holography will broaden the spectra of capabilities of MAX IV by providing fast 2D and 3D electron density images from mesoscale down to nanoscale resolution.

Low-dose phase-based X-ray imaging techniques for in situ soft tissue engineering assessments

Biomaterials ◽  
2016 ◽  
Vol 82 ◽  
pp. 151-167 ◽  
Author(s):  
Zohreh Izadifar ◽  
Ali Honaramooz ◽  
Sheldon Wiebe ◽  
George Belev ◽  
Xiongbiao Chen ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Soft Tissue ◽  
Low Dose ◽  
Imaging Techniques ◽  
X Ray ◽  
X Ray Imaging ◽  
Soft Tissue Engineering

Medium-energy microprobe station at the SXRMB of the CLS

2017 ◽  
Vol 24 (1) ◽  
pp. 333-337 ◽  
Author(s):  
Qunfeng Xiao ◽  
Aimee Maclennan ◽  
Yongfeng Hu ◽  
Mark Hackett ◽  
Peter Leinweber ◽  
...  
Keyword(s):  
Distributed Systems ◽  
Energy Range ◽  
Light Source ◽  
Biological Samples ◽  
Imaging Techniques ◽  
Chemical Imaging ◽  
Beam Size ◽  
Medium Energy ◽  
Technical Design ◽  
X Ray

Micro-XAFS and chemical imaging techniques have been widely applied for studies of heterogeneously distributed systems, mostly in hard X-ray (>5 keV) or in soft X-ray (<1.5 keV) energies. The microprobe endstation of the SXRMB (soft X-ray microcharacterization beamline) at the Canadian Light Source is optimized at the medium energy (1.7–5 keV), and it has been recently commissioned and is available for general users. The technical design and the performance (energy range, beam size and flux) of the SXRMB microprobe are presented. Examples in chemical imaging and micro-XAFS in the medium energy for important elements such as P, S and Ca for soil and biological samples are highlighted.

European low-dose radiation risk research strategy: future of research on biological effects at low doses

2014 ◽  
Vol 164 (1-2) ◽  
pp. 38-41 ◽  
Author(s):  
S. Salomaa ◽  
D. Averbeck ◽  
A. Ottolenghi ◽  
L. Sabatier ◽  
S. Bouffler ◽  
...  
Keyword(s):  
Low Dose ◽  
Biological Effects ◽  
Radiation Risk ◽  
Research Strategy ◽  
Low Doses ◽  
Low Dose Radiation ◽  
Risk Research ◽  
Dose Radiation

Arsenic segregation in polysilicon

1983 ◽  
Vol 41 ◽  
pp. 154-155 ◽  
Author(s):  
P.E. Batson ◽  
C.R.M. Grovenor ◽  
D.A. Smith ◽  
C. Wong
Keyword(s):  
Incident Beam ◽  
Silicon Wafers ◽  
Chemical Polishing ◽  
Bright Field Image ◽  
Beam Size ◽  
Stem Analysis ◽  
Bright Field ◽  
Twin Boundaries ◽  
X Ray ◽  
Line Scan

In this work As doped polysilicon was deposited onto (100) silicon wafers by APCVD at 660°C from a silane-arsine mixture, followed by a ten minute anneal at 1000°C, and in one case a further ten minute anneal at 700°C. Specimens for TEM and STEM analysis were prepared by chemical polishing. The microstructure, which is unchanged by the final 700°C anneal,is shown in Figure 1. It consists of numerous randomly oriented grains many of which contain twins.X-ray analysis was carried out in a VG HB5 STEM. As K α x-ray counts were collected from STEM scans across grain and twin boundaries, Figures 2-4. The incident beam size was about 1.5nm in diameter, and each of the 20 channels in the plots was sampled from a 1.6nm length of the approximately 30nm line scan across the boundary. The bright field image profile along the scanned line was monitored during the analysis to allow correlation between the image and the x-ray signal.

Studies of metaphase chromosomes in the scanning transmission x-ray microscope: Image fidelity, radiation damage and specimen preparation

1992 ◽  
Vol 50 (2) ◽  
pp. 1038-1039
Author(s):  
Shawn Williams ◽  
Xiaodong Zhang ◽  
Susan Lamm ◽  
Jack Van’t Hof
Keyword(s):  
Visible Light ◽  
Radiation Damage ◽  
Cross Section ◽  
Imaging Techniques ◽  
Dose Range ◽  
Specimen Preparation ◽  
X Rays ◽  
Metaphase Chromosomes ◽  
X Ray ◽  
Scanning Transmission

The Scanning Transmission X-ray Microscope (STXM) is well suited for investigating metaphase chromosome structure. The absorption cross-section of soft x-rays having energies between the carbon and oxygen K edges (284 - 531 eV) is 6 - 9.5 times greater for organic specimens than for water, which permits one to examine unstained, wet biological specimens with resolution superior to that attainable using visible light. The attenuation length of the x-rays is suitable for imaging micron thick specimens without sectioning. This large difference in cross-section yields good specimen contrast, so that fewer soft x-rays than electrons are required to image wet biological specimens at a given resolution. But most imaging techniques delivering better resolution than visible light produce radiation damage. Soft x-rays are known to be very effective in damaging biological specimens. The STXM is constructed to minimize specimen dose, but it is important to measure the actual damage induced as a function of dose in order to determine the dose range within which radiation damage does not compromise image quality.

An x-ray microprobe based upon a close-coupled focal-spot / glass capillary arrangement

1992 ◽  
Vol 50 (2) ◽  
pp. 1758-1759
Author(s):  
D. A. Carpenter ◽  
M. A. Taylor
Keyword(s):  
Imaging Techniques ◽  
Fluorescence Analysis ◽  
High Sensitivity ◽  
Specimen Preparation ◽  
X Rays ◽  
Glass Capillary ◽  
Close Coupling ◽  
X Ray ◽  
Point To Point ◽  
Beam Damage

The development of intense sources of x rays has led to renewed interest in the use of microbeams of x rays in x-ray fluorescence analysis. Sparks pointed out that the use of x rays as a probe offered the advantages of high sensitivity, low detection limits, low beam damage, and large penetration depths with minimal specimen preparation or perturbation. In addition, the option of air operation provided special advantages for examination of hydrated systems or for nondestructive microanalysis of large specimens.The disadvantages of synchrotron sources prompted the development of laboratory-based instrumentation with various schemes to maximize the beam flux while maintaining small point-to-point resolution. Nichols and Ryon developed a microprobe using a rotating anode source and a modified microdiffractometer. Cross and Wherry showed that by close-coupling the x-ray source, specimen, and detector, good intensities could be obtained for beam sizes between 30 and 100μm. More importantly, both groups combined specimen scanning with modern imaging techniques for rapid element mapping.

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