Quality improvement of general anteroposterior radiographic image of vertebral body according to optimum angle of incidence

2021 ◽  
pp. 1-10
Author(s):  
Jong Hyeok Kwak ◽  
Chi Hyung Lee ◽  
Gyeong Rip Kim ◽  
Sang Weon Lee ◽  
Young Ha Kim ◽  
...  

OBJECTIVE: In this study, we present an appropriate angle of incidence to reduce the distortions in images of L4 and L5 during a general anteroposterior radiograph examination. METHOD: We selected 170 patients who had normal radiological findings among those who underwent anteroposterior and lateral examination for lumbar vertebrae. An optimum angle of incidence wa suggested through the statistical analysis by measuring the lumbar lordosis angle and the intervertebral disc angle in these 170 patients. RESULT: We suggested the incident angle (10.28°) of L4 and the incident angle (23.49°) of L5. We compared the distorted area ratios when the incident angle was 0°, 10°, and 23.5° using the ATOM® phantom. The ratio for the L4 decreased from 14.90% to 12.11% and that of the L5 decreased from 15.25% to 13.72% after applying the angle of incidence. We determined the incident angle (9.34°) of L4 and (21.26°) of L5 below 30° of LLA. Thus, we determined the incident angle (11.21°) of L4 and (25.73°) of L5 above 30° of LLA. CONCLUSION: When you apply the optimum angle of incidence, the distortion of image was minimized and an image between the joints adjacent to the anteroposterior vertebral image with an accurate structure was obtained. As a result, we were able to improve the quality of the image and enhance diagnostic information.

Author(s):  
E. Brambrink ◽  
S. Baton ◽  
M. Koenig ◽  
R. Yurchak ◽  
N. Bidaut ◽  
...  

We have developed a new radiography setup with a short-pulse laser-driven x-ray source. Using a radiography axis perpendicular to both long- and short-pulse lasers allowed optimizing the incident angle of the short-pulse laser on the x-ray source target. The setup has been tested with various x-ray source target materials and different laser wavelengths. Signal to noise ratios are presented as well as achieved spatial resolutions. The high quality of our technique is illustrated on a plasma flow radiograph obtained during a laboratory astrophysics experiment on POLARs.


2020 ◽  
Author(s):  
Sepidehalsadat Hendi ◽  
Mostafa Gorjian ◽  
Gilles Bellefleur ◽  
Christopher D. Hawkes ◽  
Don White

Abstract. Fiber optic sensing technology has recently become popular for oil and gas, mining, geotechnical engineering, and hydrogeology applications. With a successful track record in many applications, distributed acoustic sensing using straight fiber optic cables has become a method of choice for seismic studies. However, distributed acoustic sensing using straight fiber optic cables is not able to detect off-axial strain, hence a helically wound cable design was introduced to overcome this limitation. The helically wound cable field data in New Afton deposit showed that the quality of the data is tightly dependent on the incident angle (the angle between the ray and normal vector of the surface) and surrounding media. We introduce a new analytical two-dimensional approach to determine the dynamic strain of a helically wound cable in terms of incident angle in response to elastic plane waves propagating through multilayered media. The method can be used to quickly and efficiently assess the effects of various materials surrounding a helically wound cable. Results from the proposed analytical model are compared with results from numerical modeling obtained with COMSOL Multiphysics, for scenarios corresponding to a real installation of helically wound cable deployed underground at the New Afton mine in British Columbia, Canada. Results from the analytical model are consistent with numerical modeling results. Our modeling results demonstrate the effects of cement quality, and casing installment on the quality of the helically-wound cable response. Numerical modeling results and field data suggest that, even if reasonably effective coupling achieved, the soft nature of the rocks in these intervals would result in low fiber strains for the HWC. The proposed numerical modeling workflow would be applied for more complicated scenarios (e.g., non-linear material constitutive behaviour, and the effects of pore fluids). The results of this paper can be used as a guideline for analyzing the effect of surrounding media and incident angle on the response of helically wound cable, optimizing the installation of helically wound cable in various conditions, and to validate boundary conditions of 3-D numerical model built for analyzing complex scenarios.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Qingwen Rao ◽  
Guanjun Xu ◽  
Pengfei Wang ◽  
Zhengqi Zheng

In this paper, the propagation properties of a terahertz (THz) wave in a collisional and inhomogeneous dusty plasma with a ceramic substrate and oblique angle of incidence are studied using the scattering matrix method. The influence of the various corresponding parameters, such as the frequency of the THz wave, angle of incidence, electron density, radius and density of the dust particles, and the collision frequency, on the absorbance and transmittance is calculated. The results of the simulation indicate that an increase in the wave frequency increases the transmittance and decreases the absorbance. Moreover, the absorbance of a THz wave in a dusty plasma with a ceramic substrate increases with an increase in the incident angle, maximum electron density, coefficient of steepness, density and radius of the dust particles, and collision frequency. These results provide an important theoretical basis for the problem of communication blackout between ground and spacecraft.


2015 ◽  
Vol 61 (5) ◽  
pp. 404-406 ◽  
Author(s):  
Gabriel de Deus Vieira ◽  
Alessandra Yukari Yamagishi ◽  
Natália Nogueira Vieira ◽  
Rebeka Mayara Miranda Dias Fogaça ◽  
Thaianne da Cunha Alves ◽  
...  

Summary Swyer-James syndrome is a complication of post-infectious bronchiolitis obliterans that causes inflammation and fibrosis of the bronchial walls. There are two types: asymptomatic, with most cases diagnosed in adults during routine radiological examinations; and symptomatic, most commonly found in children. Here, we report the case of a 6-year-old child with recurrent dyspnea since the age of 3, who showed signs and symptoms of bronchiolitis obliterans and radiological signs of bronchial wall thickening and air trapping. The clinical and radiological findings led to the diagnosis of Swyer-James syndrome. Treatment of this syndrome is intended to reduce the pulmonary lesions and improve the patient's quality of life.


2005 ◽  
Vol 105 ◽  
pp. 71-76 ◽  
Author(s):  
Kurt Helming ◽  
Uwe Preckwinkel

Starting from simple geometric considerations concerning directions and orientations, intelligent strategies for pole figure measurements were developed for the area detector. The amount and quality of texture information contained in measured or available data sets can be directly controlled. The texture approximation is done by the component method. The method does not have any restrictions concerning the grids of sample directions in the pole figures. An almost constant information depth can be obtained at a low angle of incidence of the primary beam for the study of thin surface layers.


2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Guiswe Gnowe ◽  
Fouda H. P. Ekobena ◽  
Amvene J. Mbo ◽  
Guena M. Neossi

Background. The purpose of this study was to estimate the doses delivered to adult patients during explorations of the sinuses and coastal grill whose attention in dosimetric terms is neglected because of the low demand for diagnosis. But yet dosimetric values are very high.Materials and Methods. The present study was transversely descriptive and was conducted between April and July 2016. The data were collected on 50 adult patients of mass of 70±10kg at the Regional Hospital of Ngaoundere (HRN). The dose at the entrance of the patients' skin was evaluated through the theoretical methods derived from the Davies model according to the 75th percentile calculations.Results and Discussion. The entrance skin doses obtained in mGy were, respectively, of 7.2±0.2 for sinuses and 5.27±0.1 for coastal grill. The present study found many variations in doses during radiological investigations. These variations allowed us to understand that the notions of quality of the radiographic image, insurance, and quality control of the radiological equipment are tributary, abstract, and often theoretical because doses delivered are not sufficiently optimized.Conclusion. The dosimetric analysis remains very worrying because the various procedures show that an improvement of the practices especially with respect to the technical parameters and the protocols must be considered. Therefore a strengthening of radiological protection skills of radiological manipulators (continuing education and retraining) would contribute to a better protection of patients.


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