High-definition Scanning Research Articles

Recycling COVID-19 health care wastes in bitumen modification: a case of disposable medical gloves.

Disposable medical gloves (DMGs) have long been used to mitigate the risk of direct exposure to diverse microorganisms and body fluids; hence, they are a critical weapon to protect patients and healthcare staff from infectious diseases. Measures to control the spread of COVID-19 have sparked the production of an excessive number of DMGs, most of which are eventually being disposed of in landfills. Untreated DMGs in landfills do not only pose a direct risk of transmitting coronavirus and other pathological germs but also pollute air, water, and soil dramatically. As a healthier alternative, recycling discarded polymer-rich DMGs into bitumen modification is considered to be a prospective waste management strategy applicable to the asphalt pavement industry. In this study, this conjecture is tested by examining two common DMGs - latex gloves and vinyl gloves - at four different percentages (1%, 2%, 3%, and 4% by weight). The morphological characteristics of DMG-modified specimens were inspected by using a high-definition scanning electron microscope (SEM) equipped with an energy dispersive X-ray analyzer (EDX). A wide range of laboratory tests including penetration, softening point temperature, ductility, and elastic recovery were undertaken to evaluate the impact of waste gloves on the conventional engineering properties of bitumen. Moreover, viscoelastic behavior and modification processing were studied by conducting the dynamic shear rheometer (DSR) test and the Fourier transform infrared spectroscopy (FTIR) analysis. Test results have revealed the outstanding potential of recycled DMG waste for modifying neat asphalt binder. More specifically, bitumens modified with 4% latex glove and 3% vinyl glove were seen as capable of superiorly withstanding permanent deformations caused by heavy axle loads at high service temperatures. Furthermore, it has been shown that 1.2 tons of modified binder would embed approximately 4000 pairs of recycled DMGs. This study shows that DMG waste can be used as a viable modifier, which would help open a new avenue for mitigating the environmental pollution arising from the COVID-19 pandemic.

Improving image quality and resolution of coronary arteries in coronary computed tomography angiography by using high-definition scans and deep learning image reconstruction.

Coronary computed tomography angiography (CTA) has been increasingly used to identify the degree of coronary artery stenosis and plaque lesions in vessels. This study evaluated the feasibility of using high-definition (HD) scanning with high-level deep learning image reconstruction (DLIR-H) to improve the image quality and spatial resolution when imaging calcified plaques and stents in coronary CTA as compared to the standard definition (SD) reconstruction mode with adaptive statistical iterative reconstruction-V (ASIR-V). A total of 34 patients (age 63.3±10.9 years; 55.88% female) with calcified plaques and/or stents who underwent coronary CTA in HD-mode were included in this study. Images were reconstructed with SD-ASIR-V, HD-ASIR-V, and HD-DLIR-H. Subjective image quality with image noise and clarity of vessels, calcifications, and stented lumens was evaluated by 2 radiologists using a 5-point scale. The kappa (κ) test was used to analyze the interobserver agreement. Objective image quality with image noise, signal-to-noise-ratio (SNR), and contrast-to-noise-ratio (CNR) was measured and compared. Image spatial resolution and beam-hardening artifacts (BHAs) were also evaluated using the calcification diameter and CT numbers in 3 points along the stented lumen (inside, at the proximal and distal ends just outside stent). There were 45 calcified plaques and 4 coronary stents. HD-DLIR-H images had the highest overall image quality score (4.50±0.63) with the lowest image noise (22.59±3.59 HU) and the highest SNR (18.30±4.88) and CNR (26.56±6.33), followed by SD-ASIR-V50% image quality score (4.06±2.49), image noise (35.02±8.09 HU), SNR (12.77±1.59), CNR(15.67±1.92) and HD-ASIR-V50% image quality score (3.90±0.64), image noise (57.7±12.03 HU), SNR (8.16±1.86), CNR (10.01±2.39). HD-DLIR-H images also had the smallest calcification diameter measurement (2.36±1.58 mm), followed by HD-ASIR-V50% (3.46±2.07 mm) and SD-ASIR-V50% (4.06±2.49 mm). HD-DLIR-H images had the closest CT value measurements for the 3 points along the stented lumen, indicating much less BHA. Interobserver agreement on the image quality assessment was good to excellent (HD-DLIR-H: κ value =0.783; HD-ASIR-V50%: κ value =0.789; SD-ASIR-V50%: κ value =0.671). Coronary CTA with HD scan mode and DLIR-H significantly improves the spatial resolution for displaying calcifications and in-stent lumens while simultaneously reducing image noise.

Association of chorioretinal thickness with chronic kidney disease

ObjectiveTo assess retinal and choroidal thickness changes in chronic kidney disease (CKD) patients using spectral domain optical coherence tomography (SD-OCT).BackgroundCKD is a devastating health trouble. The eye and the kidney share similar structural and genetic pathways, so that kidney disease and ocular disease may be closely linked. OCT is a precise, fast method for high-definition scanning of the retina and choroid.Patients and methodsA cross sectional study was conducted at Menoufia University Hospital ophthalmology department on 144 eyes of 72 CKD patients divided into 3 groups according to the stage of CKD as follows: group 1: CKD stage 1–2, with Glomerular Filtration Rate (GFR) > 60 ml/min/1.73m2 group 2: CKD stage 3, GFR 30–59 ml/min/1.73m2 and group 3: CKD stage 4–5, eGFR < 29 ml/min/1.73m2. All patients underwent full ophthalmologic examination followed by OCT assessment of retinal, retinal nerve fiber layer (RNFL) and choroidal thickness.ResultsRetinal and choroidal thickness were reduced in group 2 (CKD stage 3) and group 3 (CKD stage 4–5) compared with group 1 (CKD stage 1–2). The reduction was more severe in group 3 than group 2. RNFL thickness did not differ between groups. A thinner retina and choroid were associated with an elevated serum C-reactive protein (CRP) concentration, and greater degrees of proteinuria.ConclusionChorioretinal thinning in CKD is associated with a lower eGFR, a higher CRP, and greater proteinuria. Further studies, in a large scale of patients, are needed to detect whether these eye changes reflect the natural history of CKD.

Design of the quadrangular prism beam splitting receiving system in the MEMS-based scanning LIDAR.

The detector bandwidth and photosensitive surface aperture are the key parameters in the high-precision and high-definition scanning 3D imaging LIDAR system, which usually require a high detector bandwidth and large photosensitive surface aperture. In order to solve the problem of a high bandwidth and small photosensitive surface of existing InGaAs detectors, this paper proposes a beam splitting method using a pair of quadrangular prisms to realize beam splitting the reception of return laser beams, which increases both the receiving field of view (FOV) and the effective photosensitive surface of the detector. The principle and structure of the prism beam splitter are discussed; a beam splitting receiving optical system with a pair of quadrangular prisms is presented, and the beam splitting effect verified by its simulation experiment is analyzed. With this novel, to the best of our knowledge, light splitting receiving method, the receiving FOV can be effectively increased to ±5∘, and the effective photosensitive surface aperture of the detector can be increased from 0.5 to 1.0mm.

The process of digital fabrication and 3D printing as a tool in the study of heritage pathologies: Carcabuey Castle (Cordoba)

Highlights: High-definition scanning and 3D printing have been used as tools in the detection of heritage pathologies, as well as in the study of materials. The Carcabuey castle has been digitized and the volumetric data recovered from the study of its materials typology and its stereotomy, obtained with laser scanning. The study of construction and material phases, and the pathologies produced by them, has been carried out from the 3D printing of the heritage structure parts. Abstract: Precise documentation is essential to carry out the restoration and enhancement processes of protected heritage contexts. Data collection has been increasingly perfected, to the point of being able to perform virtual recreations of complex historical sites, in order to carry out in-depth studies and analyses. An example is Carcabuey Castle (Cordoba, Andalusia), a large fortress with important medieval structures. It is a monumental site of the so-called "Frontier Castles", which were located between the Kingdom of Aragon, and the Nasrid Kingdom of Granada. With the aim of restoring it and highlighting its value, an in-depth study was developed for its conservation and subsequent intervention. The data collection included terrestrial laser scanning and vectorising all the structures, as well as a complex and complete photogrammetric survey. From these previous data and carrying out a deductive analytical methodology, a model was generated which, after being printed in 3D (different models at different scales of detail), would allow the volumes, materials and textures which make up the castle, to be studied. The multidisciplinary team, composed of architects, archaeologists, historians and engineers, made it possible to provide multifaceted and inclusive character to all the work, both in the study of pathologies based on the models, and in the construction phases, detected by the stereotomy of the ashlars, or chemical composition of mortars. Since then, with all the data obtained in the research, summarised in this article, it has been possible to carry out a correct diagnosis for the restoration and enhancement of the heritage site.

A high capacity aqueous zinc-based chlorine ion battery improved by zinc selenide-modified anode

Chloride ion battery (CIB) is a novel anionic battery first reported in 2013. The high open circuit voltage and high theoretical capacity have attracted wide attention. However, its low cycle life imposes restrictions on its application. Since the electrochemical performance of zinc anode in chloride ion batteries is different from zinc ion batteries, we attempted to modify the zinc anode with kinds of strategies or addictives to match the zinc electrode with the zinc-free electrolyte and finally found the positive influence of ZnSe. The zinc selenide-modified anode improved the capacity to 177.4mAh g−1 and expanded the cycle life to 2500 times. Besides, our work may also have reference significance for other zinc based batteries. The mechanism of anode was analyzed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) as well as high-definition scanning electron microscopy (HD SEM) and simulated by adsorption models. The electrochemical performance of the anode was tested by cyclic voltammetry (CV) and the full cell was test on BTS4000 battery program-control test system.

Efficient Medical Image Fusion Using 2-Dimensional Double Density Wavelet Transform to Improve Quality Metrics

In the recent past, a medical 2D image fusion approach has played a vital role in the biomedical industry for diagnosing disease using various modalities of medical images. Biomedical 2D image fusion synthesis is a combining technique that merges useful information from two or more modalities of data captured through high definition scanning devices. The fused image is highly useful when doctors make emergency surgical decisions for their clinical patients. In this research, an innovative medical 2D image fusion approach called 2-Dimensional Double Density Wavelet Transform (2D-DDWT), based on maximization of scaling rule, is being proposed for the combination of CT and MRI images of human brain. The source image is applied to 2D-DDWT pursued by the fusion of sub images of coefficients based on high and low frequencies that are decomposed by transformation technique. The low frequency information is decomposed using the congruency rule of phase while the high frequency information is decomposed using 2D Gabor filter. The 2D-DDWT frequency coefficients are fused by using Principle Component Analysis (PCA) for the approximation parameters, and therefore the rule of selection maximum is being applied for the coefficients to improve features of image fusion such as segmentation. Maximization scaling rule is proposed for pixel level fusion to improve quality metrics. The quantitative and qualitative analysis proves the efficiency of the proposed methodology and demonstrates the improvement of the proposed methodology over existing methods.

Forensic Engineering Analysis of Projectile Thrown from Phantom Vehicle

This paper presents a case study involving an 8-lb “projectile” piece of concrete thrown from a phantom vehicle into the windshield of a semi-tractor truck, subsequently striking the driver’s (plaintiff’s) head. A witness told the investigating officer that the phantom vehicle was a white-rear dump truck similar to the trucks he’d seen coming in and out of a construction entrance at a nearby park. However, no follow-up investigation was conducted by investigative officers. The lead author was retained by the plaintiff’s attorney to follow up and investigate the witness’ observation of the phantom white-rear dump truck in an attempt to identify the probable source of the concrete projectile, locate the phantom vehicle, reconstruct the incident, and determine the probable cause of the incident. Several forensic engineering techniques were used during the forensic engineering investigation, including evidence analysis, photography, high-definition scanning, photogrammetry, evaluation of the accident timeline, physical testing, case study analysis, projectile analysis, and application of the process of elimination methodology. Through the forensic engineering analysis, the probable source of the projectile concrete was identified, the white-rear dump truck and driver were identified, the accident was reconstructed, and the probable cause of the accident was determined.

Evidence for microbes in early Neoproterozoic stromatolites

The biogenesis of stromatolites has long been discussed since many lack convincing evidence of their biological origin. This has particularly been the case with older Precambrian examples where widespread diagenetic and metamorphic processes have commonly destroyed microbial relics; in some cases however, evidence has been preserved through very early mineralisation. Precambrian stromatolites are relatively abundant but it is extremely rare that they contain calcified or dolomitized cyanobacteria and biofilms. This study provides evidence from early Neoproterozoic columnar stromatolites in the Jiuliqiao Formation from the southeastern margin of the North China Platform for fossilized extracellular polymeric substances (EPS) and cyanobacteria, along with nanospheres which may represent permineralised viruses or viral-like particles. A similar chemical composition and colour along with their embedded and cross-cutting relationships with the matrix suggest they are syn-depositional products, and not modern artefacts or the result of sample preparation. The interweaving of cyanobacterial filaments with detrital grains such as quartz and intraclasts indicates trapping, baffling and binding processes. The presence of virus-like particles and mineralized EPS with anhedral, fine-grained calcite suggests they may have provided initial nucleation sites for subsequent carbonate precipitation. This study demonstrates the use of a high-definition scanning electron microscope to detect fossilized (calcified) filamentous and spheroidal bacteriomorphs within ancient stromatolites in order to confirm their biogenesis.

Increasing the effective aperture of a detector and enlarging the receiving field of view in a 3D imaging lidar system through hexagonal prism beam splitting.

The detector in a highly accurate and high-definition scanning 3D imaging lidar system requires high frequency bandwidth and sufficient photosensitive area. To solve the problem of small photosensitive area of an existing indium gallium arsenide detector with a certain frequency bandwidth, this study proposes a method for increasing the receiving field of view (FOV) and enlarging the effective photosensitive aperture of such detector through hexagonal prism beam splitting. The principle and construction of hexagonal prism beam splitting is also discussed in this research. Accordingly, a receiving optical system with two hexagonal prisms is provided and the splitting beam effect of the simulation experiment is analyzed. Using this novel method, the receiving optical system's FOV can be improved effectively up to ±5°, and the effective photosensitive aperture of the detector is increased from 0.5 mm to 1.5 mm.

Optimisation of post mortem cardiac computed tomography compared to optical coherence tomography and histopathology – Technical note

Abstract Introduction Coronary atherosclerosis is a leading cause of mortality. New technological developments in computed tomography (CT), including dual energy, iterative reconstructions and high definition scanning, could significantly improve the non-invasive identification of atherosclerosis plaques. Here, a new method for optimising cardiac coronary CT with optical coherence tomography (OCT) and histopathology is presented. Materials and methods Twenty human hearts obtained from autopsies were used. A contrast agent that solidifies after cooling was injected into the coronary arteries. CT scanning was performed on the heart alone as well as with the heart in a chest phantom. We used eight different CT protocols and the newest CT technique to image every heart. The OCT and CT images were compared with their corresponding histological sections. A procedure for ensuring the correct alignment of the images was also developed. Results We have succeeded in developing a new method for post-mortem coronary CT angiography in which an autopsy heart is placed in a chest phantom to simulate clinical CT. Conclusion The new method permits comparison of CT with OCT and histopathology. This method can also be used for evaluating coronary artery disease, including characterising plaques, and will eventually allow for the detection of rupture-prone plaques, which we will assess in a future study. Clinical testing is our ultimate goal.

Analysis of Choroidal Morphologic Features and Vasculature in Healthy Eyes Using Spectral-Domain Optical Coherence Tomography

To analyze the morphologic features and vasculature of the choroid in healthy eyes using spectral-domain (SD) optical coherence tomography (OCT). Cross-sectional retrospective review. Forty-two healthy subjects (42 eyes) with no ocular disease who underwent high-definition scanning with Cirrus high-definition OCT (Carl Zeiss Meditec, Inc., Dublin, CA) at the New England Eye Center, Boston, Massachusetts, between November 2009 and September 2010. The SD OCT images were evaluated for morphologic features of the choroid, including the shape of the choroid-scleral border, location of the thickest point of choroid, and regions of focal choroidal thinning. Total choroidal thickness and large choroidal vessel layer thickness were measured by 2 independent observers experienced in analyzing OCT images using the Cirrus linear measurement tool at the fovea, 750 μm nasal and temporal to the fovea. Custom software was used to calculate the ratio of choroidal stroma to the choroidal vessel lumen. Qualitative assessment of the choroidal morphologic features, quantitative analysis of choroidal vasculature, and use of novel automated software to determine the ratio of choroidal stromal area to the area of choroidal vessel lumen. The 42 subjects had a mean age of 51.6 years. All subjects (100%) had a so-called bowl or convex shape to the choroid-sclera junction, and the thickest point of the choroid was under the fovea in 88.0% of the subjects. The mean choroidal thickness was 256.8 ± 75.8 μm, mean thickness of the large choroidal vessel layer was 204.3 ± 65.9 μm, and that of the medium choroidal vessel layer-choriocapillaris layer was 52.9 ± 20.6 μm beneath the fovea. The ratio of large choroidal vessel layer thickness to the total choroidal thickness beneath the fovea was 0.7 ± 0.06. The software-generated ratio of choroidal stromal area to the choroidal vessel lumen area was 0.27 ± 0.08, suggesting that choroidal vessel lumen forms a greater proportion of the choroid than the choroidal stroma in healthy eyes. This is the first study to describe the morphologic features and vasculature of the choroid in healthy eyes from 1-line raster scans obtained using SD OCT. The method described holds promise and has immediate clinical usefulness in recognizing subtle changes in choroidal morphologic features and the role of choroidal angiopathy in various disease states that, in the future, may inform new treatment methods. Proprietary or commercial disclosure may be found after the references.

Processing of high-definition scan data for use within building conservation practice

High-definition scanning of buildings and streets has become an increasingly common, if expensive, procedure followed within building conservation and building surveying. The available technology provides a mechanism through which extremely accurate three-dimensional data points can be rapidly collected, with a view towards the data holding potential use within modelling, design and long-term monitoring work. This is of particular relevance within the study of built cultural heritage, where interventions and activities ranging across material protection, archival research and alteration works will require detailed and reliable records of the existing built fabric. A question arises as to how large three-dimensional data can make a valuable contribution towards such recording and modelling processes. This stems from associated questions of how to deal with very large data sets in such a way that benefits can be drawn from the complexity of the dataset, without unduly hampering progress or losing accuracy. This paper considers the usefulness of the 3D data cloud, including a comparison with manual data collection. The paper concludes with a discussion regarding post-processing of data, and usefulness within building survey datasets and procedures.

Characterization of the High Temperature Strain Partitioning in Duplex Steels

A microgrid technique has been developed for the analysis of the high-temperature micro-scale strain distribution between ferrite and austenite into duplex stainless steels. The local strain is measured by micro-extensometry using square microgrids engraved on flat specimens by electro-lithography. The sample with microgrids on the surface and preliminary imaged with high definition scanning electron microscope (SEM), is inserted in a plane strain compression specimen to be deformed under conditions representative of hot rolling. After deformation, the sample is extracted from the compressed block and the surface is again analyzed by SEM and image processing to determine the strain field. The strain is heterogeneously distributed with a strong localization of the deformation, in the form of shear bands located within the ferrite and at the vicinity of the austenite/ferrite interphase boundaries. These strain maps provide useful informations about the rheology of the phases as well as about the local conditions at the origin of the damage process.

Analysis of Normal Peripapillary Choroidal Thickness via Spectral Domain Optical Coherence Tomography

To analyze the normal peripapillary choroidal thickness utilizing a commercial spectral domain optical coherence tomography (OCT) device and determine the intergrader reproducibility of this method. Retrospective, noncomparative, noninterventional case series. Thirty-six eyes of 36 normal patients seen at the New England Eye Center between April and September 2010. All patients underwent high-definition scanning with the Cirrus HD-OCT. Two raster scans were obtained per eye, a horizontal and a vertical scan, both of which were centered at the optic nerve. Two independent graders individually measured the choroidal thickness. Choroidal thickness was measured from the posterior edge of the retinal pigment epithelium to the choroid-scleral junction at 500-μm intervals away from the optic nerve in the superior, inferior, nasal, and temporal quadrants. Statistical analysis was conducted to compare mean choroidal thicknesses. Intergrader reproducibility was assessed by intraclass correlation coefficient and Pearson's correlation coefficient. Average choroidal thickness in each quadrant was compared with retinal nerve fiber layer (RNFL) thickness in their respective quadrants. Peripapillary choroidal thickness, intraclass coefficient, and Pearson's correlation coefficient. The peripapillary choroid in the inferior quadrant was significantly thinner compared with all other quadrants (P<0.001). None of the other quadrants were significantly different from each other in terms of thickness. The inferior peripapillary choroid was significantly thinner compared with all other quadrants at all distances measured away from the optic nerve (P<0.001). Generally, the peripapillary choroid increases in thickness the farther it was away from the optic nerve and eventually approaching a plateau. The intraclass correlation coefficient ranged from 0.62 to 0.93 and Pearson's correlation coefficient ranged from 0.74 to 0.95 (P<0.001). Neither RNFL thickness nor average age was significantly correlated with average choroidal thickness. Manual segmentation of the peripapillary choroidal thickness is reproducible between graders, suggesting that this method is accurate. The inferior peripapillary choroid was significantly thinner than all other quadrants (P<0.001). Proprietary or commercial disclosure may be found after the references.

114 Radiation doses trends from cardiac CT using a cardiac specific conversion factor: system understanding & an optimisation strategy significantly reduces the dose to the patients in a clinical service

BackgroundCT coronary angiography CTCA now has an established role in the investigation of patients with chest pain. Under the IRMER regulations radiation doses to patients should be kept as low...

3D high-definition scanning: Data recording and virtual modelling of the built heritage

This article discusses the use of high-definition 3D scanning in the recording and modelling of the built heritage. In particular, it explores how such technology can be used as a complement to both traditional measurement and historic records, as well as in the 3D surface modelling of heritage detail. The article uses examples from cinema buildings of the twentieth century, which arguably embody both an important physical record of society and a challenge in terms of representing a complex range of historical, cultural, economic and physical data sets. The work provides an overview of visualisation techniques that are appropriate to the subject, and provides a case study taken from the city of Aberdeen. In particular, attention is drawn towards the manner in which large and physically complicated structures can be recorded rapidly, to provide a permanent record of dimensions and building form. Furthermore, the data set produced through use of a 3D scanner can be readily translated for incorporation within architectural models such as a 3D surface mesh. The article concludes that emerging technologies will facilitate the rapid collection of highly accurate information pertaining to the still intact physical structure, where still in place, but that such data must be related directly to wider contextual information so that informed plans can be formulated for future developments, including conservation strategies.

Vibration-free stirling cryocooler for high definition microscopy

The normal operation of high definition Scanning Electronic and Helium Ion microscope tools often relies on maintaining particular components at cryogenic temperatures. This has traditionally been accomplished by using liquid coolants such as liquid Nitrogen. This inherently limits the useful temperature range to above 77 K, produces various operational hazards and typically involves elevated ownership costs, inconvenient logistics and maintenance. Mechanical coolers, over-performing the above traditional method and capable of delivering required (even below 77 K) cooling to the above cooled components, have been well-known elsewhere for many years, but their typical drawbacks, such as high purchasing cost, cooler size, low reliability and high power consumption have so far prevented their wide-spreading. Additional critical drawback is inevitable degradation of imagery performance originated from the wideband vibration export as typical for the operation of the mechanical cooler incorporating numerous movable components. Recent advances in the development of reliable, compact, reasonably priced and dynamically quiet linear cryogenic coolers gave rise to so-called “dry cooling” technologies aimed at eventually replacing the traditional use of outdated liquid Nitrogen cooling facilities. Although much improved these newer cryogenic coolers still produce relatively high vibration export which makes them incompatible with modern high definition microscopy tools. This has motivated further research activity towards developing a vibration free closed-cycle mechanical cryocooler. The authors have successfully adapted the standard low vibration Stirling cryogenic refrigerator (Ricor model K535-LV) delivering 5 W@40 K heat lift for use in vibration-sensitive high definition microscopy. This has been achieved by using passive mechanical counterbalancing of the main portion of the low frequency vibration export in combination with an active feed-forward multi-axes suppression of the residual wideband vibration, thermo-conductive vibration isolation struts and soft vibration mounts. The attainable performance of the resulting vibration free linear Stirling cryocooler (Ricor model K535-ULV) is evaluated through a full-scale experimentation.