Preparation and Quantification of Radioactive Particles for Tracking Hydrodynamic Behaviour in Multiphase Reactors

2014 ◽  
Vol 625 ◽  
pp. 509-516 ◽  
Author(s):  
Mohd Amirul Syafiq Mohd Yunos ◽  
Siti Aslina Hussain ◽  
Hamdan Mohamed Yusoff ◽  
Jaafar Abdullah

Radioactive Particle Tracking (RPT) technique has emerged as a potential and versatile technique, both in terms of richness of information and applicability to a variety of multiphase flow systems. RPT is not an off-the-shelf technique and thus has to be developed by the intended user. This paper is intended to present a simple method and procedure for preparing suitable radioactive particles tracer (Au-198 and Sc-46) irradiated simultaneously with neutrons using TRIGA Mark II research reactor. These present work focuses on the performance evaluation of encapsulated gold and scandium particle to be used as single radioactive particle tracer using qualitative and quantitative neutron activation analysis (NAA) and X-ray micro computed tomography (micro-CT) scanner installed at Malaysian Nuclear Agency.

2018 ◽  
Vol 314 (3) ◽  
pp. F493-F499 ◽  
Author(s):  
Ruslan Hlushchuk ◽  
Cédric Zubler ◽  
Sébastien Barré ◽  
Carlos Correa Shokiche ◽  
Laura Schaad ◽  
...  

In the last decades, the contrast-enhanced micro-computed tomography (micro-CT) imaging of a whole animal kidney became increasingly important. The visualization was mainly limited to middle-sized vessels. Since modern desktop micro-CT scanners provide the necessary detail resolution, we developed an approach for rapid visualization and consistent assessment of kidney vasculature and glomeruli number. This method is based on μAngiofil, a new polymerizing contrast agent with homogenous X-ray absorption, which provides continuous filling of the complete vasculature and enables correlative imaging approaches. For rapid and reliable kidney morphometry, the microangio-CT (µaCT) data sets from glial cell line-derived neurotrophic factor (GDNF)+/− mice and their wild-type littermates were used. The results were obtained much faster compared with the current gold standard, histology-based stereology, and without processing artifacts. The histology-based morphometry was done afterward on the same kidneys. Both approaches revealed that the GDNF+/− male mice had about 40% fewer glomeruli. Furthermore, our approach allows for the definition of sites of interest for further histological investigation, i.e., correlative morphology. The polymerized μAngiofil stays in perfused vessels and is autofluorescent, which is what greatly facilitates the matching of histological sections with µaCT data. The presented approach is a time-efficient, reliable, qualitative, and quantitative methodology. Besides glomerular morphometry, the µaCT data can be used for qualitative and quantitative analysis of the kidney vasculature and correlative morphology.


2021 ◽  
Author(s):  
Dominik Göldner ◽  
Fotios Alexandros Karakostis ◽  
Armando Falcucci

This protocol presents the first detailed step-by-step pipeline for the 3D scanning and post processing of large batches of lithic artefacts using a micro-computed tomography (micro-CT) scanner (i.e., a Phoenix v-tome-x S model by General Electronics MCC, Boston MA) and an Artec Space Spider scanner (Artec Inc., Luxembourg). This protocol was used to scan and analyze ca. 700 lithic artefacts from the Protoaurignacian layers at Fumane Cave in north-eastern Italy (Falcucci et al., in preparation). For this study several costly scanners and proprietary software packages were employed. Although it is not easy to find a low-budget alternative for the scanners, it is possible to use free and open-source software programs, such as 3D-Slicer (https://www.slicer.org/) or MorphoDig (https://morphomuseum.com/morphodig), to process CT data as well as MeshLab (Cignoni et al. 2008) to interact with the 3D models in general. However, if alternative software is used, the steps and their order described in this protocol might diverge significantly. A cost-effective alternative to create 3D models is digital photogrammetry using commercial cameras and freely available software like Meshroom (https://alicevision.org). Although photogrammetry is an affordable technique to create accurate 3D models of objects, this method might not be useful when scanning large batches of artefacts, as it will require a lot of computation time and processing capacity. Likewise, it could be difficult to generate accurate 3D models of very small and/or detailed tool shapes using 3D surface scanners because stone tools are often much smaller than the recommended minimum field of view. Similarly, the resolution of conventional medical CT scanners might not be sufficient to capture minor details of stone tools, such as the outline or dorsal scars. Thus, high-resolution micro-CT technology is the only reliable way to accurately capture the overall morphology of small stone tools. This protocol aims at providing the first detailed procedure dedicated to the scanning of small lithic implements for further three-dimensional analysis. Note that some of the steps must be repeated at different working stages throughout this protocol. In cases where a task must be done in the exact same way as described in a previous step, a reference to that step is provided. When slight changes were made, the step was modified and reported entirely. This protocol contains a few red and green colours (e.g., arrows or within-program colours) which might be perceived differently by people with dyschromatopsia. However, the display of these colours has been kept to a minimum. We recommend the reader to go over the entire protocol carefully, even if only some specific parts are required. A few points are in fact interdependent, and some of them must be applied simultaneously. Content: Part 1 – Styrofoam preparation Part 2 – Micro-CT scanning Part 3 – 3D model extraction of CT scanned stone artifacts using Avizo Part 4 – Cropping extracted surface model to separate Face A and B in Artec Studio Part 5 – Cropping Face A to separate the lines in Artec Studio Part 6 – Cropping each stone artefact from the lines in Artec Studio Part 7 – Virtually control measurements in MeshLab Part 8 – Artec scanning of larger artifacts Part 9 – Export meshes as non-binary ply models for successive analysis in geomorph Three-dimensional example (in ply format) of the effectivity of the StyroStone Protocol: You can download an example of one Styrofoam line in 3D obtained using our protocol to appreciate the result that can be achieved. We have selected a line where objects are characterized by different metric and morphological attributes. Notice the retouching well visible in the last five smaller artifacts (counting from the left when artifact are oriented with the dorsal face in front of the observer and the butt down), as well as the platforms and bulbs of all artifacts. For more information and examples, feel free to contact us!


2007 ◽  
Vol 103 (5) ◽  
pp. 1848-1856 ◽  
Author(s):  
Wilfred W. Lam ◽  
David W. Holdsworth ◽  
Louise Y. Du ◽  
Maria Drangova ◽  
David G. McCormack ◽  
...  

We measured ventilation (V̇) in seven anesthetized, mechanically ventilated, supine Wistar rats. Images of the whole lung were continuously acquired using a dynamic, flat-panel volumetric micro-computed tomography (micro-CT) scanner during ventilation with a xenon/oxygen (Xe-O2) gas mixture. Forty time-resolved volumes consisting of eighty 0.45-mm-thick slices (covering the entire lung) were acquired in 40 s, using a gantry rotation rate of one rotation per second. The animals were ventilated at a respiratory rate of 60 breaths/min, matching the gantry rotation rate, and imaged without suspending ventilation. A previously published theoretical model was modified slightly and used to calculate the whole lung ventilation from volumes of interest generated by seeded region growing. Linear regression of calculated whole lung ventilation volumes vs. expected tidal volumes yielded a slope of 1.12 ± 0.11 (slope ± SE) and a y-intercept of −1.56 ± 0.42 ml ( y-intercept ± SE) with 95% confidence intervals of 0.83 to 1.40 and −2.6 to −0.5 ml, respectively. The same model was used to calculate the regional ventilation in axial slices for each animal. Voxels were fit to the model to yield a map of V̇, which displayed an anterior/posterior gravitational gradient of (−3.9 ± 1.8) × 10−6 ml·s−1·cm−1 for slices immediately superior to the diaphragm and (−6.0 ± 2.4) × 10−6 ml·s−1·cm−1 for slices at the midlevel of the heart (mean ± SD). Thus continuous Xe-enhanced computed tomography enables the noninvasive determination of regional V̇ with the temporal and spatial resolution necessary for rats.


2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0001
Author(s):  
Fred Finney ◽  
Basma Khoury ◽  
Jaron Scott ◽  
Ken Kozloff ◽  
Todd Irwin ◽  
...  

Category: Basic Sciences/Biologics, Lesser Toes, Midfoot/Forefoot Introduction/Purpose: Hammertoes, crossover toes, and claw toes are common deformities and can be a major source of pain and dysfunction. These deformities result from instability of the metatarsophalangeal (MTP) joint due to incompetence of the plantar plate and/or collateral ligaments. Non-operative management is the first line of treatment. When non-operative treatment is unsuccessful, surgical interventions have been described. Newer surgical techniques focus on performing anatomic repairs of plantar plates. The vasculature of the foot has been well studied, but the vascular supply of the plantar plate has not been described. This study presents a new technique for imaging the microvasculature of the lesser toe plantar plates through micro- computed tomography (micro-CT) in order to better understand tear pathology and the capacity of healing with plantar plate repairs. Methods: The posterior tibial and dorsalis pedis arteries of a fresh frozen human cadaver foot were dissected and cannulated at the ankle for perfusion distally. After administration of an anticoagulant, each artery was perfused with Microfil® Silicone Rubber, a contrast agent. The compound was then allowed to cure, and the foot was fixed in formalin. The foot was sectioned through the metatarsal shafts for imaging, and imaging of the lesser toe MTP joints was performed using a Bruker Skyscan 1176 micro-CT scanner at 18 micron slices. Computerized reconstruction of the images was performed for three dimensional visualization of the vasculature. Results: Post-perfusion imaging of the lesser toe MTP joints using micro-CT allows for visualization of the plantar plate microvasculature. Preliminary imaging suggests that micro-CT is a useful modality for analysis of the blood supply of the plantar plate. Conclusion: Anatomic repair of the plantar plate has become a viable treatment option for MTP joint instability. One important question that remains to be answered is whether plantar plate tears have the capacity to heal. We present a novel technique for imaging of lesser toe plantar plate microvascularity using micro-CT. Preliminary results of post-perfusion imaging of the plantar plate are promising for developing a better understanding of its blood supply. Further definition of the plantar plate vascular supply will help clinicians understand the capacity for healing after repairs and may provide some insight to the biological causes plantar plate tears.


Author(s):  
Mohammadreza Fouladi ◽  
Kamran Gholami ◽  
Hossein Ghadiri

X-ray Computed Tomography (CT), e.g. clinical CT scanners, basically provides Linear Attenuation Coefficients (LACs) of objects under study by the means of algorithmic reconstruction of acquired views of attenuated X-ray passing through the samples in different angles around the imaged sample. Micro Computed Tomography (micro-CT) basically works the same as clinical CT. It provides volumetric information representing the inner structure of objects with a resolution in the micron range. LOTUS-inVivo is a micro-CT scanner dedicated to imaging of small animals and ex-vivo biological samples. In the present study the spatial resolution and Low Contrast Detectability (LCD) of LOTUS-inVivo scanner were evaluated using standard phantoms. We aimed to prove the capability of LOTUS-inVivo for small animal and ex-vivo biological samples imaging using the measured image quality parameters, i.e. spatial resolution and low contrast detectability. By the means of analysis of bar and LCD phantom images, the limiting resolution of LOTUS-inVivo micro-CT scanner was measured about 2.7 µm and has been shown that it’s capable of resolving sizes greater than 12.5 µm. Also, we concluded that LOTUS-inVivo is capable of discriminating tissues with 3% differences in contrast relative to the background, for 1 mm bar size. Thus, the provided technical characteristics in this study have made LOTUS-inVivo as a suitable tool for small animal imaging.


2015 ◽  
Vol 1084 ◽  
pp. 694-697 ◽  
Author(s):  
Andrey Batranin ◽  
Denis Ivashkov ◽  
Sergei Stuchebrov

High-resolution X-ray tomography, also known as micro-computed tomography (micro-CT) or microtomography, is a versatile evaluation technique, which extends application in various fields including material science. Micro-CT is a suitable method for quantitative and dimensional materials characterization. Needless to say, the accuracy of the method and applied equipments – micro-CT scanners – should be assessed to obtain reliable, solid results. In this paper, the performance of a micro-CT scanner as a visualization system is discussed. Quantitative parameters of image quality and visualization systems as well as methods to obtain their numerical values are briefly described. The results of experiments carried out on in-house made micro-CT scanner TOLMI-150-10 developed in Tomsk Polytechnic University are presented.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
David Haberthür ◽  
Ruslan Hlushchuk ◽  
Thomas Gerhard Wolf

AbstractHigh-resolution micro-computed tomography is a powerful tool to analyze and visualize the internal morphology of human permanent teeth. It is increasingly used for investigation of epidemiological questions to provide the dentist with the necessary information required for successful endodontic treatment. The aim of the present paper was to propose an image processing method to automate parts of the work needed to fully describe the internal morphology of human permanent teeth. One hundred and four human teeth were scanned on a high-resolution micro-CT scanner using an automatic specimen changer. Python code in a Jupyter notebook was used to verify and process the scans, prepare the datasets for description of the internal morphology and to measure the apical region of the tooth. The presented method offers an easy, non-destructive, rapid and efficient approach to scan, check and preview tomographic datasets of a large number of teeth. It is a helpful tool for the detailed description and characterization of the internal morphology of human permanent teeth using automated segmentation by means of micro-CT with full reproducibility and high standardization.


Author(s):  
Gozde Serindere ◽  
Ceren Aktuna Belgin ◽  
Kaan Orhan

Background: There are a few studies about the evaluation of maxillary first premolars internal structure with micro-computed tomography (micro-CT). The aim of this study was to assess morphological features of the pulp chamber in maxillary first premolar teeth using micro- CT. Methods: Extracted 15 maxillary first premolar teeth were selected from the patients who were in different age groups. The distance between the pulp orifices, the diameter of the pulp and the width of the pulp chamber floor were measured on the micro-CT images with the slice thickness of 13.6 µm. The number of root canal orifices and the presence of isthmus were evaluated. Results: The mean diameter of orifices was 0.73 mm on the buccal side while it was 0.61 mm on palatinal side. The mean distance between pulp orifices was 2.84 mm. The mean angle between pulp orifices was -21.53°. The mean height of pulp orifices on the buccal side was 4.32 mm while the mean height of pulp orifices on the palatinal side was 3.56 mm. The most observed shape of root canal orifices was flattened ribbon. No isthmus was found in specimens. Conclusion: Minor anatomical structures can be evaluated in more detail with micro-CT. The observation of the pulp cavity was analyzed using micro-CT.


2021 ◽  
Vol 11 (3) ◽  
pp. 891
Author(s):  
Taylor Flaherty ◽  
Maryam Tamaddon ◽  
Chaozong Liu

Osteochondral scaffold technology has emerged as a promising therapy for repairing osteochondral defects. Recent research suggests that seeding osteochondral scaffolds with bone marrow concentrate (BMC) may enhance tissue regeneration. To examine this hypothesis, this study examined subchondral bone regeneration in scaffolds with and without BMC. Ovine stifle condyle models were used for the in vivo study. Two scaffold systems (8 mm diameter and 10 mm thick) with and without BMC were implanted into the femoral condyle, and the tissues were retrieved after six months. The retrieved femoral condyles (with scaffold in) were examined using micro-computed tomography scans (micro-CT), and the micro-CT data were further analysed by ImageJ with respect to trabecular thickness, bone volume to total volume ratio (BV/TV) ratio, and degree of anisotropy of bone. Statistical analysis compared bone regeneration between scaffold groups and sub-set regions. These results were mostly insignificant (p < 0.05), with the exception of bone volume to total volume ratio when comparing scaffold composition and sub-set region. Additional trends in the data were observed. These results suggest that the scaffold composition and addition of BMC did not significantly affect bone regeneration in osteochondral defects after six months. However, this research provides data which may guide the development of future treatments.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Pei-I Tsai ◽  
Meng-Huang Wu ◽  
Yen-Yao Li ◽  
Tzu-Hung Lin ◽  
Jane S. C. Tsai ◽  
...  

Abstract Background We developed a porous Ti alloy/PEEK composite interbody cage by utilizing the advantages of polyetheretherketone (PEEK) and titanium alloy (Ti alloy) in combination with additive manufacturing technology. Methods Porous Ti alloy/PEEK composite cages were manufactured using various controlled porosities. Anterior intervertebral lumbar fusion and posterior augmentation were performed at three vertebral levels on 20 female pigs. Each level was randomly implanted with one of the five cages that were tested: a commercialized pure PEEK cage, a Ti alloy/PEEK composite cage with nonporous Ti alloy endplates, and three composite cages with porosities of 40, 60, and 80%, respectively. Micro-computed tomography (CT), backscattered-electron SEM (BSE-SEM), and histological analyses were performed. Results Micro-CT and histological analyses revealed improved bone growth in high-porosity groups. Micro-CT and BSE-SEM demonstrated that structures with high porosities, especially 60 and 80%, facilitated more bone formation inside the implant but not outside the implant. Histological analysis also showed that bone formation was higher in Ti alloy groups than in the PEEK group. Conclusion The composite cage presents the biological advantages of Ti alloy porous endplates and the mechanical and radiographic advantages of the PEEK central core, which makes it suitable for use as a single implant for intervertebral fusion.


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