SU-GG-T-416: A Quantitative Evaluation of the Effect of CT Scanning Parameters On CT Number to Density Calibration and Dose Calculations

2008 ◽  
Vol 35 (6Part15) ◽  
pp. 2820-2820
Author(s):  
S Refaei ◽  
M Lamba ◽  
H Elson
Keyword(s):  
Quantitative Evaluation ◽  
Ct Scanning ◽  
Dose Calculations ◽  
Ct Number

scholarly journals Investigation on the relationship between CT numbers and marble failure under different confining pressures

2021 ◽  
Vol 60 (1) ◽  
pp. 846-852
Author(s):  
Yang Yan-Shuang ◽  
Li Kai-Yue ◽  
Zhou Hui ◽  
Tian Hao-Yuan ◽  
Cheng Wei ◽  
...  
Keyword(s):  
Damage Mechanics ◽  
Triaxial Compression ◽  
Ct Scanning ◽  
Confining Pressure ◽  
Triaxial Tests ◽  
Compression Tests ◽  
Ct Number ◽  
Confining Pressures ◽  
Loading Tests ◽  
Rock Specimens

Abstract Computed tomography (CT) scanning technology is helpful in investigating rock materials as it can demonstrate the micro structure of rock clearly. Conventional triaxial compression tests and the corresponding graded triaxial loading tests were carried out to investigate the complex failure mechanism of the marble at the Jinping Hydropower Station. After that CT-scanning tests were done on the loaded marble specimens. The test results show that (1) the CT numbers of the specimens have a certain statistical regularity, that is, the CT numbers of the specimens under different confining pressures satisfy the Weibull distribution, as the confining pressure increases, the mean values rise while variances decrease; (2) in the two groups of tests, the average CT numbers corresponding to the conventional triaxial tests are higher than those corresponding to the graded loading tests, but the CT number variances are lower than those of the graded loading tests; and (3) according to meso-damage mechanics, the damage variables of the rock specimens were established based on the definition of CT numbers. The calculation results show that the damage variables decrease with the increase in confining pressure, the damage variables of the rock specimens in the graded loading tests are higher than those in the conventional triaxial test, and the differences between the two loading tests have grown with the increase in confining pressure.

scholarly journals Detection of Alcohol-Induced Fatty Liver by Computerized Tomography

1988 ◽  
Vol 81 (3) ◽  
pp. 149-151 ◽  
Author(s):  
S L Allaway ◽  
C D Ritchie ◽  
D Robinson ◽  
T Seear ◽  
R Reznek ◽  
...  
Keyword(s):  
Liver Function ◽  
Fatty Liver ◽  
Ct Scanning ◽  
Normal Liver ◽  
Liver Function Tests ◽  
Variable Degree ◽  
Normal Liver Function ◽  
Gamma Glutamyl Transpeptidase ◽  
Ct Number ◽  
Heavy Drinkers

Computerized tomographic (CT) scanning of the liver was undertaken in 17 occasional and 19 heavy drinkers undergoing health screening. The median attenuation value of the liver (CT number) in occasional drinkers with normal liver function tests was 54.4 compared with 25.9 in the heavy drinkers (P < 0.001). Fourteen of the heavy drinkers had a CT number below the lowest value observed in occasional drinkers with normal liver function, indicating reduced liver density due to fatty change. Serum gamma-glutamyl transpeptidase was normal in 36% of these individuals. A rise in CT number was observed in 4 out of 5 heavy drinkers who underwent a second scan after decreasing their alcohol consumption. These findings suggest that CT scanning provides a noninvasive and convenient method of screening for a fatty liver, which occurred to a variable degree in over 70% of the men who admitted to regularly taking 8 or more alcoholic drinks per day.

Real-Time Computerized Tomography of Clay Deformation during Triaxial Compression

2012 ◽  
Vol 433-440 ◽  
pp. 4377-4383
Author(s):  
Hong Sun ◽  
Xiu Run Ge ◽  
Fu Jun Niu ◽  
Ming Xun Hou
Keyword(s):  
Real Time ◽  
Computerized Tomography ◽  
Triaxial Compression ◽  
Strain Curve ◽  
Ct Scanning ◽  
Localized Deformation ◽  
Ct Number ◽  
Triaxial Loading ◽  
Structure Changes ◽  
Time Scanning

Clay is a kind of structured material, and its inner structure changes with the loading. Therefore it is meaningful to analyze the deformation characteristics of clay at mesoscale. Real-time Computerized Tomography (CT) scanning experiments of clay subjected to triaxial loading were performed. The most significant aspect of the study was that real-time scanning was performed without unloading during shearing test. The deformation of clay subjected to triaxial loading is basically manifested by uniform deformation at the mesoscale. If clay structure and adhesions between soil particles are of big difference, the deformation is manifested by localized deformation. The latter average CT number-strain curve is divided into three stages as: (a) damage starts; (b) damage develops; and (c) softening failure.

scholarly journals Quantitative analysis of concrete on the basis of fuzzy set and computerised tomography number

2020 ◽  
Vol 24 (6 Part B) ◽  
pp. 3907-3913
Author(s):  
Jian-Yin Fang ◽  
Na Li ◽  
Fei Qu ◽  
Zhan-Shuang Dou ◽  
Shu-Tian Li
Keyword(s):  
Uniaxial Compression ◽  
Ct Scanning ◽  
Spiral Ct ◽  
Hardened Cement ◽  
Ct Scanner ◽  
Ct Number ◽  
Portable Power ◽  
Power Loading ◽  
Aggregate Rate ◽  
Ct Test

In this study, the portable power loading device and medical Marconi M8000 spiral CT scanner are used to conduct the uniaxial compression CT scanning test of the concrete. The concrete porosity, hardened cement rate, and aggregate rate are defined, and the variation law of the concrete is analyzed in the uniaxial compression CT test. The proposed method is considered to utilize the value of each CT number, to realize the quantitative partition of the various components of concrete, and to quantitatively evaluate the damage evolution law of the concrete and strain localization during stress. It is shown that damage at the middle section increased from inside to the outside in the uniaxial compression CT test of the concrete.

scholarly journals PHOTON BEAM DOSE CALCULATIONS USING ELECTRON DENSITY FROM CT NUMBER

1981 ◽  
Vol 37 (6) ◽  
pp. 729-737
Author(s):  
KESATO YANO ◽  
KIYOSHI MARUYAMA ◽  
MASAOMI TAKIZAWA ◽  
KATSUTO TAKEMURA
Keyword(s):  
Electron Density ◽  
Photon Beam ◽  
Dose Calculations ◽  
Ct Number ◽  
Beam Dose

scholarly journals Experiment Analysis of Concrete’s Mechanical Property Deterioration Suffered Sulfate Attack and Drying-Wetting Cycles

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Wei Tian ◽  
Nv Han
Keyword(s):  
Inductively Coupled Plasma ◽  
Ct Scanning ◽  
Sulfate Solution ◽  
Sulfate Attack ◽  
Salt Crystallization ◽  
Ct Number ◽  
Inductively Coupled ◽  
Concrete Deterioration ◽  
Deterioration Process ◽  
Expansion Force

The mechanism of concrete deterioration in sodium sulfate solution is investigated. The macroperformance was characterized via its apparent properties, mass loss, and compressive strength. Changes in ions in the solution at different sulfate attack periods were tested by inductively coupled plasma (ICP). The damage evolution law, as well as analysis of the concrete’s meso- and microstructure, was revealed by scanning electron microscope (SEM) and computed tomography (CT) scanning equipment. The results show that the characteristics of concrete differed at each sulfate attack period; the drying-wetting cycles generally accelerated the deterioration process of concrete. In the early sulfate attack period, the pore structure of the concrete was filled with sulfate attack products (e.g., ettringite and gypsum), and its mass and strength increased. The pore size and porosity decreased while the CT number increased. As deterioration progressed, the swelling/expansion force of products and the salt crystallization pressure of sulfate crystals acted on the inner wall of the concrete to accumulate damage and accelerate deterioration. The mass and strength of concrete sharply decreased. The number and volume of pores increased, and the pore grew more quickly resulting in initiation and expansion of microcracks while the CT number decreased.

Radiopaque and biodegradable beads fabricated with Lipiodol and polycaprolactone for transarterial chemoembolization

MRS Advances ◽  
2019 ◽  
Vol 4 (20) ◽  
pp. 1187-1192
Author(s):  
Yutaka Okamoto ◽  
Kenta Bito ◽  
Terumitsu Hasebe ◽  
Tomohiro Matsumoto ◽  
Atsushi Hotta
Keyword(s):  
Microfluidic Device ◽  
Transarterial Chemoembolization ◽  
Ct Scanning ◽  
Flow Rate Ratio ◽  
Embolic Agent ◽  
Ct Number ◽  
Weight Loss Data ◽  
Fluoroscopic Imaging ◽  
Ethiodized Oil ◽  
The Mean

AbstractEmbolic beads for transarterial chemoembolization (TACE) should possess radiopacity and biodegradability at the same time, to be visualized in a body under fluoroscopy and CT scanning to avoid complicating disease. In this study, we fabricated radiopaque and biodegradable beads composed of Lipiodol (LPD) (ethiodized oil) and polycaprolactone (PCL), a biocompatible and biodegradable polymer. LPD/PCL beads were first fabricated with a home-made microfluidic device. By changing the flow-rate ratio in the microfluidic device, the mean diameter of LPD/PCL beads could be well controlled. The radiopacity was evaluated by the fluoroscopic imaging and the CT number measurements. Furthermore, the biodegradability was evaluated by collecting the weight loss data of LPD/PCL immersed in lipase/PBS solution and PBS. The results showed that LPD/PCL beads obtained in this study had sufficient radiopacity and biodegradability, which would be an alternative embolic agent for TACE.

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