Time-lapse x ray microscope movie of the germinating garden pea seed

1992 ◽  
Vol 50 (1) ◽  
pp. 836-837
Author(s):  
Sterling Newberry ◽  
J. A. Vozzo ◽  
Michael Marko
Keyword(s):  
Time Lapse ◽  
Test Material ◽  
X Rays ◽  
Garden Pea ◽  
Low Contrast ◽  
X Ray ◽  
Minimum Number ◽  
Plant Embryo ◽  
Pea Seed ◽  
Suitable Environment

The plant embryo is relatively insensitive to x-rays. One should like to take advantage of this property to follow the early processes of seed germination by time-lapse x-ray microscopy. Preliminary work has shown that radiation exposure can be reduced by two orders of magnitude if a minimum number of frames are exposed and the movie then generated by slowly dissolving one frame into the next. Image processing also helps the problem of low contrast in the living image. Present work has been directed against the problem that geotropism makes the embryo grow out of the plane of the picture (the instrument does not operate horizontally). The approach taken should also simplify the problems of maintaining a suitable environment for the seed and make the instrument available between exposures when working with seeds which have long germination times. The garden pea was chosen as a test material because of its environmental tolerance, short maturation cycle, and similarity to pine seeds in size and radiation tolerance.

scholarly journals Tracking Lung Tumors in Orthogonal X-Rays

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Feng Li ◽  
Fatih Porikli
Keyword(s):  
Regression Model ◽  
Window Size ◽  
Average Error ◽  
X Rays ◽  
Orthogonal Axis ◽  
Low Contrast ◽  
X Ray ◽  
Imaging Artifacts ◽  
Image Pairs ◽  
Optimal Window

This paper presents a computationally very efficient, robust, automatic tracking method that does not require any implanted fiducials for low-contrast tumors. First, it generates a set of motion hypotheses and computes corresponding feature vectors in local windows within orthogonal-axis X-ray images. Then, it fits a regression model that maps features to 3D tumor motions by minimizing geodesic distances on motion manifold. These hypotheses can be jointly generated in 3D to learn a single 3D regression model or in 2D through back projection to learn two 2D models separately. Tumor is tracked by applying regression to the consecutive image pairs while selecting optimal window size at every time. Evaluations are performed on orthogonal X-ray videos of 10 patients. Comparative experimental results demonstrate superior accuracy (~1 pixel average error) and robustness to varying imaging artifacts and noise at the same time.

Rapid Quantitative Analysis by X-Ray Spectrometry

1971 ◽  
Vol 15 ◽  
pp. 164-175 ◽  
Author(s):  
Robert D. Giauque ◽  
Joseph M. Jaklevic
Keyword(s):  
Cross Sections ◽  
Fluorescence Analysis ◽  
Selective Excitation ◽  
Single Element ◽  
X Rays ◽  
Analysis Method ◽  
Yield Data ◽  
X Ray ◽  
Minimum Number ◽  
Sample Dilution

An x-ray fluorescence analysis method applicable to the case of fluorescent spectra excited with monoenergetic x-rays has been developed. The technique employs a minimum number of calibration steps using single element thin film standards and depends upon theoretical cross sections and fluorescent yield data to interpolate from element to element. The samples are treated as thin films and corrections for absorption effects are easily determined- Enhancement effects, if not negligible, are minimized by sample dilution techniques or by selective excitation.

Predict pneumonia with chest X-ray images based on convolutional deep neural learning networks

2020 ◽  
Vol 39 (3) ◽  
pp. 2893-2907 ◽  
Author(s):  
Huaiguang Wu ◽  
Pengjie Xie ◽  
Huiyi Zhang ◽  
Daiyi Li ◽  
Ming Cheng
Keyword(s):  
Median Filter ◽  
Recognition Rate ◽  
Identification System ◽  
X Rays ◽  
Learning Networks ◽  
Low Contrast ◽  
X Ray ◽  
Detection Model ◽  
Chest X Ray ◽  
Fitting In

The chest X-ray examination is one of the most important methods for screening and diagnosing of many lung diseases. Diagnosis of pneumonia by chest X-ray is one of the common methods used by medical experts. However, the image quality of chest X-Ray has some defects, such as low contrast, overlapping organs and blurred boundary, which seriously affects detecting pneumonia in chest X-rays. Therefore, it has important medical value and application significance to construct a stable and accurate automatic detection model of pneumonia through a large number of chest X-ray images. In this paper, we propose a novel hybrid system for detecting pneumonia from chest X-Ray image: ACNN-RF, which is an adaptive median filter Convolutional Neural Network (CNN) recognition model based on Random forest (RF). Firstly, the improved adaptive median filtering is employed to remove noise in the chest X-ray image, which makes the image more easily recognized. Secondly, we establish the CNN architecture based on Dropout to extract deep activation features from each chest X-ray image. Finally, we employ the RF classifier based on GridSearchCV class as a classifier for deep activation features in CNN model. It not only avoids the phenomenon of over-fitting in data training, but also improves the accuracy of image classification. During our experiment, the public chest X-ray image dataset used in the experiment contains 5863 images, which comprises 4265 frontal-view X-ray images of 1574 unique patients. The average recognition rate of pneumonia is up to 97% by the proposed ACNN-RF. The experimental results show that the ACNN-RF identification system is more effective than the previous traditional image identification system.

A deformation rig for synchrotron microtomography studies of geomaterials under conditions down to 10 km depth in the Earth

2016 ◽  
Vol 23 (4) ◽  
pp. 1030-1034 ◽  
Author(s):  
François Renard ◽  
Benoit Cordonnier ◽  
Dag K. Dysthe ◽  
Elodie Boller ◽  
Paul Tafforeau ◽  
...  
Keyword(s):  
Axial Stress ◽  
Confining Pressure ◽  
Time Lapse ◽  
High Energy ◽  
Aqueous Fluid ◽  
Coupled Processes ◽  
Porous Solids ◽  
Data Sets ◽  
X Rays ◽  
X Ray

A hard X-ray transparent triaxial deformation apparatus, called HADES, has been developed by Sanchez Technologies and installed on the microtomography beamline ID19 at the European Radiation Synchrotron Facility (ESRF). This rig can be used for time-lapse microtomography studies of the deformation of porous solids (rocks, ceramics, metallic foams) at conditions of confining pressure to 100 MPa, axial stress to 200 MPa, temperature to 250°C, and controlled aqueous fluid flow. It is transparent to high-energy X-rays above 60 keV and can be used forin situstudies of coupled processes that involve deformation and chemical reactions. The rig can be installed at synchrotron radiation sources able to deliver a high-flux polychromatic beam in the hard X-ray range to acquire tomographic data sets with a voxel size in the range 0.7–6.5 µm in less than two minutes.

scholarly journals A comparison of different approaches for imaging cracks in composites by X-ray microtomography

2016 ◽  
Vol 374 (2071) ◽  
pp. 20160037 ◽  
Author(s):  
B. Yu ◽  
R. S. Bradley ◽  
C. Soutis ◽  
P. J. Withers
Keyword(s):  
Composite Materials ◽  
High Resolution ◽  
Structural Integrity ◽  
Three Dimensional ◽  
Time Lapse ◽  
Large Area ◽  
User Friendliness ◽  
Low Contrast ◽  
X Ray ◽  
Defect Detectability

X-ray computed tomography (CT) has emerged as a key imaging tool in the characterization of materials, allowing three-dimensional visualization of an object non-destructively as well as enabling the monitoring of damage accumulation over time through time-lapse imaging. However, small defects and cracks can be difficult to detect, particularly in composite materials where low-contrast, plate-like geometries of large area can compromise detectability. Here, we investigate a number of strategies aimed at increasing the capability of X-ray CT to detect composite damage such as transverse ply cracking and delamination, looking specifically at a woven glass fibre-reinforced three-dimensional composite. High-resolution region of interest (ROI) scanning, in situ loading, phase contrast and contrast agents are examined systematically as strategies for improving the defect detectability. Spatial resolution, contrast, signal-to-noise ratio, full width at half maximum, user friendliness and measurement time are all considered. Taken together, the results suggest that high-resolution ROI scanning combined with the increased contrast resulting from staining give the highest defect detectability. This article is part of the themed issue ‘Multiscale modelling of the structural integrity of composite materials’.

scholarly journals X-ray near-field speckle: implementation and critical analysis

2011 ◽  
Vol 18 (6) ◽  
pp. 823-834 ◽  
Author(s):  
Xinhui Lu ◽  
S. G. J. Mochrie ◽  
S. Narayanan ◽  
A. R. Sandy ◽  
M. Sprung
Keyword(s):  
Near Field ◽  
Numerical Aperture ◽  
Main Beam ◽  
X Rays ◽  
Measured Intensity ◽  
Low Contrast ◽  
X Ray ◽  
Area Detector ◽  
X Ray Scattering

The newly introduced coherence-based technique of X-ray near-field speckle (XNFS) has been implemented at 8-ID-I at the Advanced Photon Source. In the near-field regime of high-brilliance synchrotron X-rays scattered from a sample of interest, it turns out that, when the scattered radiation and the main beam both impinge upon an X-ray area detector, the measured intensity shows low-contrast speckles, resulting from interference between the incident and scattered beams. A micrometer-resolution XNFS detector with a high numerical aperture microscope objective has been built and its capability for studying static structures and dynamics at longer length scales than traditional far-field X-ray scattering techniques is demonstrated. Specifically, the dynamics of dilute silica and polystyrene colloidal samples are characterized. This study reveals certain limitations of the XNFS technique, especially in the characterization of static structures, which is discussed.

scholarly journals Detection of the bone contours of the knee joints on medical X-ray images

2019 ◽  
Vol 43 (3) ◽  
pp. 455-463
Author(s):  
А.A. Mikhaylichenko ◽  
Y.М. Demyanenko
Keyword(s):  
Quality Evaluation ◽  
Knee Joints ◽  
Intermediate Step ◽  
X Rays ◽  
Detection Problem ◽  
Low Contrast ◽  
X Ray ◽  
Alternative Approach ◽  
Detection Of Objects ◽  
The Common

Detection of objects of interest is a crucial step in the automatic analysis of the medical X-ray images. However, medical X-rays are often characterized by the low contrast as well as great variability in range of colours, which makes it more difficult to be analysed by the common methods based on the regions homogeneity principles. In our paper, we present an alternative approach to the contours detection problem that does not require the homogeneity criteria to be satisfied. Our method is based on the identification of edge fragments and elimination of discontinuities between them. Moreover, we describe a numeric criterion for quality evaluation of contours detection. The obtained results can used for diagnosis of abnormalities and diseases, and also as an intermediate step for more sophisticated methods of image analysis.

scholarly journals Comparison of Rhenium and Iodine as Contrast Agents in X-Ray Imaging

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
José Carlos De La Vega ◽  
Pedro Luis Esquinas ◽  
Jovan Kaur Gill ◽  
Selin Jessa ◽  
Bradford Gill ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Atomic Number ◽  
Imaging Techniques ◽  
Absorbed Dose ◽  
X Rays ◽  
Micro Computed Tomography ◽  
Low Contrast ◽  
X Ray ◽  
X Ray Imaging ◽  
The Difference

Purpose. The majority of X-ray contrast agents (XCA) are made with iodine, but iodine-based XCA (I-XCA) exhibit low contrast in high kVp X-rays due to iodine’s low atomic number (Z = 53) and K-edge (33.1 keV). While rhenium is a transition metal with a high atomic number (Z = 75) and K-edge (71.7 keV), the utilization of rhenium-based XCA (Re-XCA) in X-ray imaging techniques has not been studied in depth. Our study had two objectives: (1) to compare both the image quality and the absorbed dose of I- and Re-XCA and (2) to prepare and image a rhenium-doped scaffold. Procedures. I- and Re-XCA were prepared and imaged from 50 to 120 kVp by Micro-computed tomography (µCT) and digital radiography and from 120 to 220 kVp by planar X-ray imaging. The scans were repeated using 0.1 to 1.6 mm thick copper filters to harden the X-ray beam. A rhenium-doped scaffold was prepared via electrospinning, used to coat catheters, and imaged at 90 kVp by µCT. Results. I-XCA have a greater contrast-to-noise ratio (CNR) at 50 and 80 kVp, but Re-XCA have a greater CNR at >120 kVp. The difference in CNR is increased as the thickness of the copper filters is increased. For instance, the percent CNR improvement of rhenium over iodine is 14.2% with a 0.6 mm thick copper filter, but it is 59.1% with a 1.6 mm thick copper filter, as shown at 120 kVp by µCT. Upon coating them with a rhenium-doped scaffold, the catheters became radiopaque. Conclusions. Using Monte Carlo simulations, we showed that it is possible to reduce the absorbed dose of high kVp X-rays while allowing the acquisition of high-quality images. Furthermore, radiopaque catheters have the potential of enhancing the contrast during catheterizations and helping physicians to place catheters inside patients more rapidly and precisely.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Chemical Species Identification in an SEM by Changes in Emitted X-Ray Energies

1974 ◽  
Vol 32 ◽  
pp. 570-571
Author(s):  
R. H. Duff
Keyword(s):  
Species Identification ◽  
Valence Electron ◽  
Chemical Species ◽  
X Rays ◽  
Chemical Bonds ◽  
Small Shift ◽  
X Ray ◽  
Electron Transitions ◽  
Peak Energy ◽  
Chemical Combination

A material irradiated with electrons emits x-rays having energies characteristic of the elements present. Chemical combination between elements results in a small shift of the peak energies of these characteristic x-rays because chemical bonds between different elements have different energies. The energy differences of the characteristic x-rays resulting from valence electron transitions can be used to identify the chemical species present and to obtain information about the chemical bond itself. Although these peak-energy shifts have been well known for a number of years, their use for chemical-species identification in small volumes of material was not realized until the development of the electron microprobe.

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