scholarly journals Advances in functional X-ray imaging techniques and contrast agents

2012 ◽  
Vol 14 (39) ◽  
pp. 13469 ◽  
Author(s):  
Hongyu Chen ◽  
Melissa M. Rogalski ◽  
Jeffrey N. Anker
Keyword(s):  
Contrast Agents ◽  
Imaging Techniques ◽  
X Ray ◽  
X Ray Imaging

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.

scholarly journals X-Ray Imaging Techniques Appraisal: Pathway to Sustainable Health Status

2021 ◽  
Vol 655 (1) ◽  
pp. 012073
Author(s):  
J. A. Achuka ◽  
M. R. Usikalu ◽  
M. A. Aweda ◽  
O. A. Olowoyeye ◽  
C. A. Enemuwe ◽  
...  
Keyword(s):  
Health Status ◽  
Imaging Techniques ◽  
X Ray ◽  
X Ray Imaging ◽  
Sustainable Health

Non-radioactive imaging strategies for in vivo immune cell tracking

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Łukasz Kiraga ◽  
Paulina Kucharzewska ◽  
Damian Strzemecki ◽  
Tomasz P. Rygiel ◽  
Magdalena Król
Keyword(s):  
Diagnostic Imaging ◽  
Contrast Agents ◽  
Cell Tracking ◽  
Immune Cell ◽  
Imaging Techniques ◽  
Diagnostic Technique ◽  
Cell Labeling ◽  
X Ray Imaging ◽  
Disease Study

Abstract In vivo tracking of administered cells chosen for specific disease treatment may be conducted by diagnostic imaging techniques preceded by cell labeling with special contrast agents. The most commonly used agents are those with radioactive properties, however their use in research is often impossible. This review paper focuses on the essential aspect of cell tracking with the exclusion of radioisotope tracers, therefore we compare application of different types of non-radioactive contrast agents (cell tracers), methods of cell labeling and application of various techniques for cell tracking, which are commonly used in preclinical or clinical studies. We discuss diagnostic imaging methods belonging to three groups: (1) Contrast-enhanced X-ray imaging, (2) Magnetic resonance imaging, and (3) Optical imaging. In addition, we present some interesting data from our own research on tracking immune cell with the use of discussed methods. Finally, we introduce an algorithm which may be useful for researchers planning leukocyte targeting studies, which may help to choose the appropriate cell type, contrast agent and diagnostic technique for particular disease study.

scholarly journals Truncated Inception Net: COVID-19 Outbreak Screening using Chest X-rays

2020 ◽  
Author(s):  
Dipayan Das ◽  
KC Santosh ◽  
Umapada Pal
Keyword(s):  
Neural Network ◽  
World Wide ◽  
Imaging Techniques ◽  
Imaging Systems ◽  
Ct Scans ◽  
X Rays ◽  
X Ray ◽  
X Ray Imaging ◽  
Proposed Model ◽  
Different Types

Abstract Since December 2019, the Coronavirus Disease (COVID-19) pandemic has caused world-wide turmoil in less than a couple of months, and the infection, caused by SARS-CoV-2, is spreading at an unprecedented rate. AI-driven tools are used to identify Coronavirus outbreaks as well as forecast their nature of spread, where imaging techniques are widely used, such as CT scans and chest X-rays (CXRs). In this paper, motivated by the fact that X-ray imaging systems are more prevalent and cheaper than CT scan systems, a deep learning-based Convolutional Neural Network (CNN) model, which we call Truncated Inception Net, is proposed to screen COVID-19 positive CXRs from other non-COVID and/or healthy cases. To validate our proposal, six different types of datasets were employed by taking the following CXRs: COVID-19 positive, Pneumonia positive, Tuberculosis positive, and healthy cases into account. The proposed model achieved an accuracy of 99.96% (AUC of 1.0) in classifying COVID- 19 positive cases from combined Pneumonia and healthy cases. Similarly, it achieved an accuracy of 99.92% (AUC of 0.99) in classifying COVID-19 positive cases from combined Pneumonia, Tuberculosis and healthy CXRs. To the best of our knowledge, as of now, the achieved results outperform the existing AI-driven tools for screening COVID-19 using CXRs.

scholarly journals Bent Laue crystal anatomy: new insights into focusing and energy-dispersion properties

2021 ◽  
Vol 54 (2) ◽  
pp. 409-426
Author(s):  
Peng Qi ◽  
Xianbo Shi ◽  
Nazanin Samadi ◽  
Dean Chapman
Keyword(s):  
Ray Tracing ◽  
Imaging Techniques ◽  
Point Of View ◽  
Energy Dispersion ◽  
General Behaviour ◽  
X Ray ◽  
Spatial Properties ◽  
X Ray Imaging ◽  
Special Cases ◽  
Intuitive View

X-ray Laue-type monochromators are common and essential optical components at many high-power X-ray facilities, e.g. synchrotron facilities. The X-ray optics of bent Laue crystals is a well developed area. An incident X-ray beam penetrating a bent Laue crystal will result in a diffracted beam with different angles and energies. There is a need for a way of organizing the rays that allows one to sort out the energy and spatial properties of the diffracted beam. The present work introduces a new approach for describing the general behaviour of bent Laue crystals from a ray-tracing point of view. This quasi-monochromatic beam approach provides an intuitive view of bent-crystal diffraction and leads to deeper understanding. It explains the energy and spatial properties of common and special cases of bent Laue optics, predicts phenomena that can improve energy-dispersion-related X-ray imaging techniques and provides a theoretical framework that makes ray-tracing simulation easier to realize.

In-Situ/Operando Synchrotron X-ray Imaging Techniques for Energy-Related Applications

2021 ◽  
pp. 223-247
Author(s):  
Lei Du ◽  
Nan Sun ◽  
Yajie Song ◽  
Hanwen An ◽  
Jian Liu
Keyword(s):  
Imaging Techniques ◽  
X Ray ◽  
X Ray Imaging

High-resolution monochromatic X-ray imaging techniques applied to Shenguang Ⅱ laser facility

2013 ◽  
Vol 25 (12) ◽  
pp. 3119-3122 ◽  
Author(s):  
陈伯伦 Chen Bolun ◽  
杨正华 Yang Zhenghua ◽  
韦敏习 Wei Minxi ◽  
邓博 Deng Bo ◽  
苏明 Su Ming ◽  
...  
Keyword(s):  
High Resolution ◽  
Imaging Techniques ◽  
X Ray ◽  
X Ray Imaging ◽  
Laser Facility

scholarly journals Optimization of the energy for Breast monochromatic absorption X-ray Computed Tomography

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pasquale Delogu ◽  
Vittorio Di Trapani ◽  
Luca Brombal ◽  
Giovanni Mettivier ◽  
Angelo Taibi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Imaging Techniques ◽  
Fixed Dose ◽  
X Rays ◽  
Reconstruction Algorithms ◽  
Contrast Resolution ◽  
X Ray ◽  
X Ray Imaging ◽  
X Ray Computed ◽  
Dose Levels

Abstract The limits of mammography have led to an increasing interest on possible alternatives such as the breast Computed Tomography (bCT). The common goal of all X-ray imaging techniques is to achieve the optimal contrast resolution, measured through the Contrast to Noise Ratio (CNR), while minimizing the radiological risks, quantified by the dose. Both dose and CNR depend on the energy and the intensity of the X-rays employed for the specific imaging technique. Some attempts to determine an optimal energy for bCT have suggested the range 22 keV–34 keV, some others instead suggested the range 50 keV–60 keV depending on the parameters considered in the study. Recent experimental works, based on the use of monochromatic radiation and breast specimens, show that energies around 32 keV give better image quality respect to setups based on higher energies. In this paper we report a systematic study aiming at defining the range of energies that maximizes the CNR at fixed dose in bCT. The study evaluates several compositions and diameters of the breast and includes various reconstruction algorithms as well as different dose levels. The results show that a good compromise between CNR and dose is obtained using energies around 28 keV.

Examining Effects of Sulfur Poisoning on Ni/YSZ Solid Oxide Fuel Cell Anodes Using Synchrotron-Based X-Ray Imaging Techniques

2013 ◽  
Author(s):  
William M. Harris ◽  
Jeffrey J. Lombardo ◽  
George J. Nelson ◽  
Wilson K. S. Chiu ◽  
Barry Lai ◽  
...  
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Imaging Techniques ◽  
Solid Oxide ◽  
Sulfur Poisoning ◽  
Oxide Fuel ◽  
Stabilized Zirconia ◽  
X Ray ◽  
Fuel Flexibility ◽  
X Ray Imaging ◽  
Ppm Level

Fuel flexibility is widely considered one of the most significant advantages of solid oxide fuel cells (SOFC). However, the presence of small amounts of sulfur or other impurities in the gas stream can have a serious impact on cell performance [1–10]. Under certain conditions, hydrogen sulfide (H2S), even at the ppm level, can lead to the formation of bulk nickel-sulfides within the conventional Ni–yttria-stabilized zirconia (Ni-YSZ) anode of SOFC’s [9]. Understanding the distribution of these sulfides is critical to describing their effects on the electrochemical activity of the cell.

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