Single-center experience of using high definition (Hi-Def) imaging during neurointervention treatment of intracranial aneurysms using flow diverters

2020 ◽  
Vol 12 (9) ◽  
pp. 897-901
Author(s):  
Swetadri Vasan Setlur Nagesh ◽  
Kunal Vakharia ◽  
Muhammad Waqas ◽  
Stephan A Munich ◽  
Daniel R Bednarek ◽  
...  
Keyword(s):  
Intracranial Aneurysms ◽  
Detector System ◽  
Large Field ◽  
Medical Systems ◽  
High Definition ◽  
Treatment Area ◽  
X Ray ◽  
The Mean ◽  
The Impact ◽  
Flow Diverters

BackgroundA new dual resolution imaging x-ray detector system (Canon Medical Systems Corporation, Tochigi, Japan) has a standard resolution 194 µm pixel conventional flat-panel detector (FPD) mode and a high-resolution 76 µm high-definition (Hi-Def) mode in a single unit. The Hi-Def mode enhances the visualization of the intravascular devices.ObjectiveWe report the clinical experience and physician evaluation of this new detector system with Hi-Def mode for the treatment of intracranial aneurysms using a Pipeline embolization device (PED).MethodsDuring intervention at our institute, under large field of view (FOV) regular resolution FPD mode imaging, the catheter systems and devices were first guided to the proximity of the treatment area. Final placement and deployment of the PED was performed under Hi-Def mode guidance. A post-procedure 9-question physician survey was conducted to qualitatively assess the impact of Hi-Def mode visualization on physicians’ intraoperative decision-making. One-sample t-test was performed on the responses from the survey. Dose values reported by the x-ray unit were also recorded.ResultsTwenty-five cases were included in our study. The survey results indicated that, for each of the nine questions, the physicians in all cases indicated that the Hi-Def mode improved visualization compared with the FPD mode. For the 25 cases, the mean cumulative entrance air kerma was 2.35 Gy, the mean dose area product (DAP) was 173.71 Gy.cm2, and the mean x-ray exposure time was 39.30 min.ConclusionsThe Hi-Def mode improves visualization of flow diverters and may help in achieving more accurate placement and deployment of devices.

IMPACT OF BEAUVERIA BASSIANA ON THE COTTONWOOD BORER, PLECTRODERA SCALATOR (COLEOPTERA: CERAMBYCIDAE), IN A COMMERCIAL COTTONWOOD NURSERY.

1989 ◽  
Vol 24 (2) ◽  
pp. 186-190 ◽  
Author(s):  
B. T. Forschler ◽  
G. L. Nordin
Keyword(s):  
Beauveria Bassiana ◽  
Populus Deltoides ◽  
Adult Population ◽  
Control Treatment ◽  
High Dose ◽  
Flight Period ◽  
Treatment Area ◽  
Larval Population ◽  
The Mean ◽  
The Impact

A commercial Beauveria bassiana (Balsamo) Vuillemin conidial formulation, AGB 6178, was applied as a soil drench against the cottonwood borer, Plectrodera scalator (F.), in a commercial eastern cottonwood, Populus deltoides, nursery. Doses of 0, 2 × 109, 2 × 1010 and 1 × 1011 conidia/m2 were applied in June 1986. The adult population was monitored throughout its flight period (June–August) for B. bassiana infection. Greater than 60% of the adults collected in the treatment area post-treatment were infected with B. bassiana. The impact of the fungal application on the larval population was assessed 8 months later by the removal and dissection of the treated rootstocks. Though no differences were detected in the number of second-year larvae recovered, the mean number of first-year larvae found at the high dose (1 × 1011 CFU's/m2) was significantly less (LSD, alpha 0.05) than the mean number of larvae found in the control treatment (0 CFU's/m2), 5.0 and 9.4 larvae/10 rootstocks, respectively.

Dry Effect of Cementitious Materials on Testing Results of X-Ray CT

2012 ◽  
Vol 450-451 ◽  
pp. 187-192 ◽  
Author(s):  
Jian De Han ◽  
Wei Sun ◽  
Gang Hua Pan
Keyword(s):  
Cement Paste ◽  
Three Dimensional ◽  
Cementitious Materials ◽  
Drying Process ◽  
X Ray ◽  
Before And After ◽  
X Ray Computed ◽  
The Mean ◽  
The Impact ◽  
Gray Values

In this study three-dimensional X-ray computed tomography (X-ray CT) is used to investigate the testing results differences of cement paste and mortar before and after drying. It can be found that the mean gray values of paste and mortar before drying are bigger than after drying, and the impact of drying on cement paste is more serious than mortar. In addition, the porosity of non-drying cement paste and mortar is 1.10% and 0.43%, while that of drying cement paste and mortar is 1.55% and 0.70%, respectively. So, the porosity of paste and mortar markedly increases after drying process. The numbers of pores of paste and mortar sharply increase after drying process in particular between 0.01mm3 and 0.1mm3. The impact of drying on smaller pores is more serious than bigger pores.

scholarly journals Are We Overdoing It? Changes in Diagnostic Imaging Workload during the Years 2010–2020 including the Impact of the SARS-CoV-2 Pandemic

Healthcare ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1557
Author(s):  
Mateusz Winder ◽  
Aleksander Jerzy Owczarek ◽  
Jerzy Chudek ◽  
Joanna Pilch-Kowalczyk ◽  
Jan Baron
Keyword(s):  
Healthcare Expenditure ◽  
University Hospital ◽  
X Rays ◽  
X Ray ◽  
Number Of Patients ◽  
The Future ◽  
The Mean ◽  
The Impact ◽  
Annual Amount ◽  
Related Increase

Since the 1990s, there has been a significant increase in the number of imaging examinations as well as a related increase in the healthcare expenditure and the exposure of the population to X-rays. This study aimed to analyze the workload trends in radiology during the last decade, including the impact of COVID-19 in a single university hospital in Poland and to identify possible solutions to the challenges that radiology could face in the future. We compared the annual amount of computed tomography (CT), radiography (X-ray), and ultrasound (US) examinations performed between the years 2010 and 2020 and analyzed the changes in the number of practicing radiologists in Poland. The mean number of patients treated in our hospital was 60,727 per year. During the last decade, the number of CT and US examinations nearly doubled (from 87.4 to 155.7 and from 52.1 to 86.5 per 1000 patients in 2010 and 2020 respectively), while X-ray examinations decreased from 115.1 to 96.9 per 1000 patients. The SARS-CoV-2 pandemic did not change the workload trends as more chest examinations were performed. AI, which contributed to the COVID-19 diagnosis, could aid radiologists in the future with the growing workload by increasing the efficiency of radiology departments as well as by potentially minimizing the related costs.

scholarly journals An Experimental Intervention Study Assessing the Impact of a Thin Silicone Gel Surface Overlay on Interface Pressure

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Seth Kwadjo Angmorterh ◽  
Andrew England ◽  
Sonia Aboagye ◽  
Eric Kwasi Ofori ◽  
Peter Hogg
Keyword(s):  
Financial Burden ◽  
T Test ◽  
Radiotherapy Planning ◽  
Test Results ◽  
Interface Pressure ◽  
X Ray ◽  
Silicone Gel ◽  
Paired Samples ◽  
The Mean ◽  
The Impact

Introduction. The incidence of pressure ulcers (PUs) presents a substantial threat to patients, especially geriatric patients, those with restricted mobility, and patients suffering from chronic diseases such as cancer. PUs creates a huge financial burden on healthcare authorities and patients, costing billions to treat and manage. Radiography and radiotherapy patients may experience medical device related (MDR) PUs and studies have shown that high interface pressure (IP) values exist for the head when placed on an X-ray table without a mattress. These high IP values pose a PU risk to patients, especially those accessing prolonged radiography/radiology and radiotherapy procedures. The current study assessed the impact on IP values for the head from using a thin silicone gel surface overlay during radiographic procedures and identified whether this reduced the risk of PUs. Materials and Methods. A calibrated XSENSOR pressure mat was used to measure IP for the head on an X-ray table with and without a thin silicone gel surface overlay. Prior to pressure mapping, the silicone gel surface overlay was assessed for its impact on radiation attenuation and image quality. Results. Study participants were 14 males (70%) and six females (30%), with an age range of 25–53 years (mean = 34.4 ± 7.0). Paired-samples t-test results indicated that there was a statistically significant decrease in the mean IP for the head on the X-ray table without the silicone gel surface overlay (mean = 83.9 ± 8.2 in mmHg) and the X-ray table with the gel surface overlay (mean = 62.4 ± 6.1 in mmHg), p ≤ 0.001 . Paired-samples t-test results indicated that there was a statistically significant decrease in the mean peak pressure index (PPI) for the head on the X-ray table without the silicone gel surface overlay (mean = 205.1 ± 28.2 in mmHg) and the X-ray table with the gel surface overlay (mean = 159.8 ± 26.8 in mmHg), p ≤ 0.001 . Conclusions. The use of a thin silicone gel surface overlay could reduce IP risk for the head by approximately 25%. The reduction in IP risk could have a significant impact in reducing the risk of developing a PU. To ensure maximum benefit, the silicone gel surface overlay should be evaluated to address the specific needs within radiography and radiotherapy planning and treatment settings.

scholarly journals Effect of Bi Content on the Microstructure and Mechanical Performance of Sn-1Ag-0.5Cu Solder Alloy

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 314
Author(s):  
Heba Y. Zahran ◽  
Ashraf S. Mahmoud ◽  
Alaa F. Abd El-Rehim
Keyword(s):  
Solder Alloy ◽  
Mechanical Performance ◽  
Testing Temperature ◽  
Mean Value ◽  
X Ray Diffraction ◽  
Preliminary Assessment ◽  
X Ray ◽  
Creep Measurements ◽  
The Mean ◽  
The Impact

The purpose of this work is to explore the impact of 0.5, 1.5, 2.5 and 3.5 wt.% Bi additions on the microstructure and mechanical performance of Sn-1Ag-0.5Cu solder alloy. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were utilized to examine the microstructure of the present solders. Creep measurements have been used for the preliminary assessment of mechanical properties. The steady-state creep rate, έst, diminished as the Bi’s concentration increased and reached 2.5 wt.%, with this trend altering above this point. Furthermore, increasing the aging or testing temperature caused the έst values to increment for all the investigated solders. έst variations with different Bi content and aging temperature were observed by examining the Sn-Ag-Cu solders’ structural evolutions. The mean value of the activation energy of all investigated solder alloys was found to be ∼52 kJ/mol. This value is appropriate to that quoted for the dislocation climb through the core diffusion as the dominant operating mechanism. The XRD findings supported the microstructure and lattice parameters variations with both aging temperatures and bismuth concentrations.

scholarly journals The Impact of Cooling Flows in Clusters of Galaxies

2000 ◽  
Vol 195 ◽  
pp. 199-206
Author(s):  
S. W. Allen
Keyword(s):  
Gravitational Lensing ◽  
Theoretical Models ◽  
Clusters Of Galaxies ◽  
X Ray ◽  
Cooling Flows ◽  
Cooling Flow ◽  
A Value ◽  
Best Fitting ◽  
The Mean ◽  
The Impact

I discuss the impact of cooling flows on the observable X-ray properties of clusters of galaxies. I show that accounting for the effects of cooling flows and subcluster merger events leads to consistent determinations of the distribution of gravitating matter in clusters from X-ray and gravitational lensing studies. Accounting for the effects of cooling flows significantly reduces the scatter in the LBol/TX relation determined for the hottest, most luminous systems and changes the best-fitting slope of the relation to a value close to LBol ∝ T2X, in agreement with theoretical models. A clear segregation between the mean metallicities of cooling-flow and non-cooling-flow clusters is observed, which can be explained by the presence of metallicity gradients in the cooling-flow systems.

scholarly journals Supernovae in Binary Systems : Production of Run-Away Stars and Pulsars

1982 ◽  
Vol 69 ◽  
pp. 417-443
Author(s):  
Jean-Pierre De Cuyper
Keyword(s):  
Binary Systems ◽  
Extreme Values ◽  
Supernova Explosion ◽  
Keplerian Orbit ◽  
Radio Pulsars ◽  
X Ray ◽  
Ob Stars ◽  
Supernova Shell ◽  
The Mean ◽  
The Impact

AbstractThe effects of an instantaneous asymmetric supernova explosion in an eccentric binary system are analyzed, taking into account the mass loss out of the system, the influence of the impact of the supernova shell on the companion star and the extra “kick” velocity which a collapsed star might receive in an asymmetric supernova explosion. For a random orientat-ion in space of this asymmetric kick velocity, the survival probability and the runaway velocities are derived and their properties discussed for an explosion occurring at a given position in the initial keplerian orbit and the mean and extreme values of these quantities over one orbit are derived. As an example, the outcome of a possible supernova explosion in the ten best known WR+OB binaries is studied and a comparison is made with the observed run-away OB stars, radio pulsars and binary X-ray pulsars.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

Isomorphous replacement in electron diffraction of wet crystals of rat hemoglobin

1983 ◽  
Vol 41 ◽  
pp. 446-447
Author(s):  
William F. Tivol ◽  
Murray Vernon King ◽  
D. F. Parsons
Keyword(s):  
Electron Diffraction ◽  
Heavy Atom ◽  
Isomorphous Substitution ◽  
X Ray Diffraction ◽  
Salt Solutions ◽  
X Ray ◽  
Isomorphous Replacement ◽  
Structure Factors ◽  
Diffraction Structure ◽  
The Mean

Feasibility of isomorphous substitution in electron diffraction is supported by a calculation of the mean alteration of the electron-diffraction structure factors for hemoglobin crystals caused by substituting two mercury atoms per molecule, following Green, Ingram & Perutz, but with allowance for the proportionality of f to Z3/4 for electron diffraction. This yields a mean net change in F of 12.5%, as contrasted with 22.8% for x-ray diffraction.Use of the hydration chamber in electron diffraction opens prospects for examining many proteins that yield only very thin crystals not suitable for x-ray diffraction. Examination in the wet state avoids treatments that could cause translocation of the heavy-atom labels or distortion of the crystal. Combined with low-fluence techniques, it enables study of the protein in a state as close to native as possible.We have undertaken a study of crystals of rat hemoglobin by electron diffraction in the wet state. Rat hemoglobin offers a certain advantage for hydration-chamber work over other hemoglobins in that it can be crystallized from distilled water instead of salt solutions.

Long-period modulated superstructures in Pd-12.5 at.%Ce and Pd-15 at.%Ce alloys

1990 ◽  
Vol 48 (4) ◽  
pp. 164-165
Author(s):  
Noriyuki Kuwano ◽  
Masaru Itakura ◽  
Kensuke Oki
Keyword(s):  
Electron Microscopy ◽  
Mean Value ◽  
Heavy Elements ◽  
Arc Furnace ◽  
X Ray ◽  
Long Period ◽  
Ultra High Purity ◽  
Heat Treated ◽  
Atomic Scattering ◽  
The Mean

Pd-Ce alloys exhibit various anomalies in physical properties due to mixed valences of Ce, and the anomalies are thought to be strongly related with the crystal structures. Since Pd and Ce are both heavy elements, relative magnitudes of (fcc-fpd) are so small compared with <f> that superlattice reflections, even if any, sometimes cannot be detected in conventional x-ray powder patterns, where fee and fpd are atomic scattering factors of Ce and Pd, and <f> the mean value in the crystal. However, superlattices in Pd-Ce alloys can be analyzed by electron microscopy, thanks to the high detectability of electron diffraction. In this work, we investigated modulated superstructures in alloys with 12.5 and 15.0 at.%Ce.Ingots of Pd-Ce alloys were prepared in an arc furnace under atmosphere of ultra high purity argon. The disc specimens cut out from the ingots were heat-treated in vacuum and electrothinned to electron transparency by a jet method.

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