scholarly journals Post-mortem X-ray computed tomography (PMCT) identification using ante-mortem CT-scan of the sphenoid sinus

2019 ◽  
Vol 46 (4) ◽  
pp. 248-255 ◽  
Author(s):  
Lucile Deloire ◽  
Idris Diallo ◽  
Romain Cadieu ◽  
Mathieu Auffret ◽  
Zarrin Alavi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Ct Scan ◽  
Sphenoid Sinus ◽  
Post Mortem ◽  
X Ray ◽  
X Ray Computed

Flows Through Real Porous Media: X-Ray Computed Tomography, Experiments, and Numerical Simulations

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Wim-Paul Breugem ◽  
Vincent van Dijk ◽  
René Delfos
Keyword(s):  
Computed Tomography ◽  
Porous Medium ◽  
Ct Scan ◽  
Numerical Simulations ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Immersed Boundary ◽  
Immersed Boundary Methods ◽  
X Ray ◽  
X Ray Computed

Two different direct-forcing immersed boundary methods (IBMs) were applied for the purpose of simulating slow flow through a real porous medium: the volume penalization IBM and the stress IBM. The porous medium was a random close packing of about 9000 glass beads in a round tube. The packing geometry was determined from an X-ray computed tomography (CT) scan in terms of the distribution of the truncated solid volume fraction (either 0 or 1) on a three-dimensional Cartesian grid. The scan resolution corresponded to 19.3 grid cells over the mean bead diameter. A facility was built to experimentally determine the permeability of the packing. Numerical simulations were performed for the same packing based on the CT scan data. For both IBMs the numerically determined permeability based on the Richardson extrapolation was just 10% lower than the experimentally found value. As expected, at finite grid resolution the stress IBM appeared to be the most accurate IBM.

Estimating the depth of the restrictive layer of soil in a cranberry field based on CT scan images

2020 ◽  
Author(s):  
Elnaz Shahriarinia ◽  
Silvio Jose Gumiere ◽  
Christian Dupuis
Keyword(s):  
Computed Tomography ◽  
Ct Scan ◽  
Fine Particles ◽  
Pore Network ◽  
Imaging Method ◽  
Pore Characteristics ◽  
Soil Particles ◽  
X Ray ◽  
Soil Media ◽  
X Ray Computed

<p><strong>Estimating the depth of the restrictive layer of soil in a cranberry field based on CT scan images</strong></p><p> </p><p>Cranberry production is a dominant culture in Québec, Canada. In cranberry production, there is a substantial need for water whether for irrigation, harvesting, or frost control. Some farms are implementing subirrigation procedures in order to reduce water use and increase fruit yields. However, this irrigation method may impose hydraulic stresses on soil particles which results in the movement of fine particles. The accumulation of the soil particles in narrow pore throats leads to the formation of restrictive layers in soil.  In this respect, we are going to study the changes in soil media and its porosity based on X-ray computed tomography (CT) which is a non-destructive imaging method. Consequently, X-ray CT has become a great asset to analyze soil physical properties. With the analysis of the images captured by the use of X-ray computed tomography, it is possible to visualize and analyze the pore network structure in the soil media.</p><p> </p><p>This study reports the results of subirrigation experiments for four different sandy soils. These column experiments aimed to reproduce the effects of subirrigation in cranberry fields for 40 years. Seven different time steps were taken with a medical CT scanner SOMATOM Definition AS+ 128 (Siemens, Germany). The 2-D horizontal 16-bit gray-scale images were captured by an X-ray energy level of 140 KeV. For each column, we got 1677 images of 512  512 pixels with a voxel size of 0.1 × 0.1 × 0.6 mm (x, y, z). Studying our images for further analysis, we used several global and local methods to find the most reliable and efficient one to binarize our images. Results show that the methods and the image analysis neighborhood have a great impact on the accuracy of the image segmentation. We were able to reconstruct a 3-D visualization of the soil pore network for each column. We used this reconstruction to demonstrate that the variation of porosity and soil pore characteristics can be studied over time. We find that the transport of soil particles tends to be highest when there are fine sandy soil particles on top of a layer of coarse soil. These finer particles have sufficient energy to be remobilized within the pore network while coarser particles remain in place. Our results show that soil particle transport can be assessed using time-lapse imagery and thus makes it possible to approximate the depth and amount of time that will be required for these restrictive layers to form in different soil profiles. Finally, it would be possible to find the best structure of soil in construction of a cranberry field in the future.</p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p>

Synthesizing Dental Radiographs for Human Identification

2007 ◽  
Vol 86 (11) ◽  
pp. 1057-1062 ◽  
Author(s):  
S. Tohnak ◽  
A.J.H. Mehnert ◽  
M. Mahoney ◽  
S. Crozier
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Human Remains ◽  
Geometric Distortion ◽  
Post Mortem ◽  
X Ray ◽  
X Ray Computed ◽  
Dental Radiographs ◽  
Ct Data ◽  
Comparison Algorithms

The task of identifying human remains based on dental comparisons of post mortem (PM) and ante mortem (AM) radiographs is labor-intensive, subjective, and has several drawbacks, including: inherently poor image quality, difficulty matching the viewing angles in PM radiographs to those taken AM, and the fact that the state of the dental remains may entirely preclude the possibility of obtaining certain types of radiographs PM. The aim of the present study was to investigate the feasibility of using radiograph-like images reconstructed from PM x-ray computed tomography (CT) data to overcome the shortcomings of conventional radiographic comparison. Algorithms for computer synthesis of panoramic, periapical, and bitewing images are presented. The algorithms were evaluated with data from clinical examinations of two persons. The results demonstrate the efficacy of the CT-based approach and that, in comparison with conventional radiographs, the synthesized images exhibit minimal geometric distortion, reduced blurring, and reduced superimposition of oral structures.

VirtoScan - a mobile, low-cost photogrammetry setup for fast post-mortem 3D full-body documentations in x-ray computed tomography and autopsy suites

2017 ◽  
Vol 13 (1) ◽  
pp. 34-43 ◽  
Author(s):  
Sören Kottner ◽  
Lars C. Ebert ◽  
Garyfalia Ampanozi ◽  
Marcel Braun ◽  
Michael J. Thali ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Low Cost ◽  
Post Mortem ◽  
X Ray ◽  
X Ray Computed ◽  
Full Body

scholarly journals Multispectral 3D Whole-Body Imaging of Dressed and Undressed Bodies in Combination with Post-Mortem X-Ray Computed Tomography

2021 ◽  
Author(s):  
Soeren KOTTNER ◽  
Martin M. SCHULZ ◽  
Florian BERGER ◽  
Michael J. THALI ◽  
Dominic GASCHO
Keyword(s):  
Computed Tomography ◽  
Whole Body ◽  
Whole Body Imaging ◽  
Post Mortem ◽  
Body Imaging ◽  
X Ray ◽  
X Ray Computed

X-Ray Computed Tomography of Ultralightweight Metals

1999 ◽  
Vol 11 (1) ◽  
pp. 199-211
Author(s):  
J. M. Winter ◽  
R. E. Green ◽  
A. M. Waters ◽  
W. H. Green
Keyword(s):  
Computed Tomography ◽  
X Ray ◽  
X Ray Computed

Requesting physicians’ knowledge of X-radiation exposure from computed tomography scan examinations: A case study of two Nigerian tertiary hospitals

2020 ◽  
Vol 3 ◽  
pp. 36-39
Author(s):  
Samson O. Paulinus ◽  
Benjamin E. Udoh ◽  
Bassey E. Archibong ◽  
Akpama E. Egong ◽  
Akwa E. Erim ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Ionizing Radiation ◽  
Ct Scan ◽  
Radiation Exposure ◽  
Work Experience ◽  
Radiation Risk ◽  
Radiological Protection ◽  
X Ray ◽  
Tertiary Hospitals ◽  
Medical Exposure

Objective: Physicians who often request for computed tomography (CT) scan examinations are expected to have sound knowledge of radiation exposure (risks) to patients in line with the basic radiation protection principles according to the International Commission on Radiological Protection (ICRP), the Protection of Persons Undergoing Medical Exposure or Treatment (POPUMET), and the Ionizing Radiation (Medical Exposure) Regulations (IR(ME)R). The aim is to assess the level of requesting physicians’ knowledge of ionizing radiation from CT scan examinations in two Nigerian tertiary hospitals. Materials and Methods: An 18-item-based questionnaire was distributed to 141 practicing medical doctors, excluding radiologists with work experience from 0 to >16 years in two major teaching hospitals in Nigeria with a return rate of 69%, using a voluntary sampling technique. Results: The results showed that 25% of the respondents identified CT thorax, abdomen, and pelvis examination as having the highest radiation risk, while 22% said that it was a conventional chest X-ray. Furthermore, 14% concluded that CT head had the highest risk while 9% gave their answer to be conventional abdominal X-ray. In addition, 17% inferred that magnetic resonance imaging had the highest radiation risk while 11% had no idea. Furthermore, 25.5% of the respondents have had training on ionizing radiation from CT scan examinations while 74.5% had no training. Majority (90%) of the respondents were not aware of the ICRP guidelines for requesting investigations with very little (<3%) or no knowledge (0%) on the POPUMET and the IR(ME)R respectively. Conclusion: There is low level of knowledge of ionizing radiation from CT scan examinations among requesting physicians in the study locations.

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