• Journal of the Korean Society for Precision Engineering
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• v.26 no.10
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• pp.129-133
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• 2009

Considerable attention has been focused on digital X-ray systems with transmission. However, only a few attempts have been made using X-ray backscatter systems. This study developed a Data Acquisition System (DAS) for backscattered X-rays. The imaging system used X-ray backscatter at low energy levels, which has unique advantages in terms of acquiring information that cannot be obtained using the transmission system. Such systems are of potential benefit in the medical, industrial, security and military fields because of its practical benefits and the low doses used. The developed system is a similar body scan system. Experiments were carried out using a several metal materials and a fish, which produces results similar to those obtained using the human body during X-ray testing.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.400-403
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• 2002

The fundamental experiments for measuring soft x-ray characteristics from the vacuum capillary are described. These experiments were primarily performed in order to generate line spectra such as x-ray lasers. The generator consists of a high-voltage power supply, a polarity-inversion ignitron pulse generator, a turbo-molecular pump, and a radiation tube with a capillary. A high-voltage condenser of 200 nF in the pulse generator is charged up to 20 kV by the power supply, and the electric charges in the condenser are discharged to the capillary in the tube after closing the ignitron. During the discharge, weakly ionized plasma forms on the inner and outer sides of a capillary. In the present work, the pump evacuates air from the tube with a pressure of about 1 mPa, and a demountable capillary was developed in order to measure x-ray spectra according to changes in the capillary length. In this capillary, the anode (target) and cathode elements can be changed corresponding to the objectives. The capillary diameter is 2.0 mm, and the length is adjusted from 1 to 50 mm. When a capillary with aluminum anode and cathode electrodes was employed, both the cathode voltage and the discharge current almost displayed damped oscillations. The peak values of the voltage and current increased when the charging voltage was increased, and their maximum values were -10.8 kV and 4.7 kA, respectively. The x-ray durations observed by a 1.6 ${\mu}$m aluminum filter were less than 30 ${\mu}$s, and we detected the aluminum characteristic x-ray intensity using a 6.8 ${\mu}$m aluminum filter. In the spectrum measurement, two sets of aluminum and titanium electrodes were employed, and we observed multi-line spectra. The line photon energies seldom varied according to changes in the condenser charging voltage and to changes in the electrode element. In the case where the titanium electrode was employed, the line number decreased with corresponding decreases in the capillary length. Compared with incoherent visible light, these rays from the capillary were diffracted and diffused greatly after passing through two slits.

• Journal of Radiation Industry
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• v.10 no.4
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• pp.249-255
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• 2016

This study, Seoul City shelter, you are trying to seek medical cooperation and cure rate increase proposal Yu findings's current situation and tuberculosis of homeless tuberculosis. Inspector, and has a total 591 people is targeted to implement an interview after acquiring utilization agreement in studies conducted chest X-ray photography. Of the interview questions, three or more protons, it is determined that the TB symptomatic conducted sputum examination, chest X-ray examination confirms the physician radiology, when sputum examination primarily chromatic findings the double implemented and conducted by requesting the ship inspection also said inspection sputum acid-fast bacteria if it is true one, respectively. confirmed case result of checking whether there is a difference due to risk factors(Jb) at the chi square black, it was found that there is no statistically significant difference at 95% confidence level. (${\chi}^2=0.276$, p>0.05), suspected case (Ac, Ae) results of examining whether there is a difference due to risk factors in chi square black, that there is a statistically significant difference at 99% confidence level is I found (${\chi}^2=9.414$, p<0.01). The nature of the homeless tuberculosis screening and directed to the distance homeless specific location are likely to evaluate the actual incidence low and aggressive or management needs, the rationale is allowed insufficient reality is. Through this research, future, for tuberculosis high risk tuberculosis patient, such as homeless to expand the tuberculosis screening of infectious tuberculosis patients in private medical institutions, and one-stop service that chest X-ray examination and sputum examination is carried out at the same time introduced immediately to prevent the inspection and examination, cure, and should establish a foundation that can be up to post administration.

• Journal of Korean society of Dental Hygiene
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• v.17 no.6
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• pp.1053-1065
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• 2017

Objectives: The purpose of this study is to evaluate radiation safety education, knowledge and practice of dental hygienists in using handheld portable intraoral X-ray equipment and to suggest the need for radiation safety education in using handheld portable intraoral X-ray equipment. Methods: We surveyed 223 dental hygienists from July, 2017 to August in the dental clinics of Daejeon, Seoul and Gyeonggi area. Results: Radiation safety educational experience was higher in a year's career (72.9%), than 3 years experience (32.5%) (p<0.05). 82.7% of dental clinic workers took university education for radiation safety education while 55.6% of dental hospital workers took company training (p<0.05). More than 70% of the subjects did not have experience of radiation safety education about using portable intraoral X-ray. Radiation safety knowledge was highest in a year's career (p<0.05). The cumulative dose, radiation sensitivity, and lead defense knowledge were high in all subjects, but knowledge related to scattering radiation and scattering radiation sources was low. Practice of portable intraoral X-ray safety was significantly lower than knowledge. Conclusions: Knowledge of portable intraoral radiography safety is available, but performance is poor. Even with the small amount of radiation exposure, the risk is perceivable. There is a need to actively utilize the provided radiation protection products. In order to do this, efforts should be made to improve knowledge and performance of radiation safety through not only college education but also postemployment training.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.287-295
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• 2012

This study aims to develop the methods for effective patient flow in the medical center through simulation modeling. To achieve this, we developed three simulation scenarios based on max/min processing time and addition of X-ray by 15 patient tracks from real hospital data. The simulation software used in this study is Flexsim HC 2.7. According to the scenario 1 on 15 patient tracks' LOS by max processing time, there is a great difference between average length of stay(LOS) and max LOS. And average LOS increases greatly depending on the number of patients by the hours. There is no need to add extra X-ray because the addition of X-ray has not much influence in average LOS. It is possible to make good decisions on patient flow management and medical equipment purchasing through simulation modeling. The concrete simulation scenario as a tool for decision support will contribute to efficiency in hospital management.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.379-381
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• 2002

A single CdZnTe detector is tested for suitability in a prototype CT/ SPECT system designed to acquire both emission and transmission data. The detector has the size of 1${\times}$l-cm$^2$ with 4${\times}$4 1.5${\times}$l.5mm$^2$ pixellated anodes. Since the detector is smaller than imaged object, we translated it in an arc centered at the x-ray tube to image larger objects. Pulse counting electronics with very short shaping time (50 ns) are used to satisfy high photon rates in x-ray imaging, and response linearity up to 3${\times}$10$\^$5/ counts per second per detector element is achieved. The energy resolution of 122-keV gamma-ray is measured to be 14%. We have characterized the system performance by scanning a radiographic resolution phantom .and the Hoffman brain phantom. The spatial resolution of CT and SPECT are about 1 mm and 7 mm, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.395-398
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• 2002

Many research group started study to develope x-ray detector using thin film transistor from 1970. But realization of TFT based x-ray detector development was caused by progress of thin film transistor liquid crystal display(TFTLCD) device technology in 1990. The main current of TFT technology is display device. Research results expend TFT technology field from display device to sensor manufacture technology. These days many research group in the world realize various digital x-ray detector. In this study, We compare discharge erasing method to visible light erasing method in a-Se based digital x-ray detector. Visible light erasing method is known reset process in direct conversion x-ray detector. Digital x-ray detector using visible light erasing method is not adaptive for conventional x-ray device, because of its thickness. And it is not avaliable for real-time imaging for digital fluoroscopy, because of its long reset time. In this study we overcome these limitations and show new idea for real-time imaging method.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.148-152
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• 2007

In this paper, we have synthesized $Gd_2O_3:Eu^{3+}$ nano phosphor particle using a low temperature solution-combustion method. We have investigated the structure and the luminescent characteristic as the sintering temperature and europium concentration. From XRD(X-ray diffraction) and SEM(scanning electron microscope) results, we have verified that the phosphor particle was fabricated a spherical shape with $30{\sim}40nm$ particle size. From the photoluminescence results, the strong peak exhibits at 611 um and the luminescent intensity depends on europium concentration. $Gd_2O_3:Eu$ fine phosphor particle has shown excellent luminescent efficiency at 5 wt% of europium concentration. The phosphors calcinated at $500^{\circ}C$ have possessed the x-ray peaks corresponding to the cubic phase of $Gd_2O_3$. As calcinations temperature increased to $700^{\circ}C$, the new monoclinic phase has identified except cubic patterns. From the luminescent decay time measurements, mean lifetimes were $2.3{\sim}2.6ms$ relatively higher than conventional bulk phosphors. These results indicate that $Gd_2O_3:Eu$ nano phosphor is possible for the operation at the low x-ray dose, therefore, the application as medical imaging detector.

• Korean Journal of Bronchoesophagology
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• v.6 no.2
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• pp.159-163
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• 2000

The patient with findings of diffuse infiltrative lung on chest X-ray has various causes; therefore, the prognosis is different and the treatment should be changed according to the cause. We are trying to identify the meaning of operative lung biopsy and to 11nd a more accurate and effective procedure. We reviewed 46 medical records of patients with the findings of diffuse infiltrative lung on chest X-ray who had undergone operative lung biopsy or biopsies for 8 years. The open lung biopsy were done in 22 cases(47.8%) and thoracoscopic lung biopsy in 24 cases(52.2%). There is no significant difference in the rate of diagnosis(p=0.452) and the incidence of complications(p=0.155) between these groups. The number of cases with more than two biopsies are 9(19.6%) and that of one biopsy are 37(80.4%). There are no statistical difference in the rate of diagnosis(p=0.928) and the incidence of complications(p=0.125). The postoperative complications occurred in 8 cases,7 cases of air leak more than 7 days and 1 case of respiratory insufficiency. In the diagnosis and treatment of the patients with findings of infiltrative lung on chest X-ray, the operative lung biopsy is the very necessary course, and shows satisfactory rate of diagnosis with negligible complications.

• Journal of radiological science and technology
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• v.41 no.1
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• pp.47-51
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• 2018

To evaluate the applicability of osteoporosis management by statistical analysis of the correlation between bone mineral density (BMD) changes after menopause by dividing the T-score of bone mineral density measured by dual energy X-ray absorptiometry do. Between January 1, 2016 and July 31, 2017, women who visited the medical center of W Medical Center were enrolled in this study. The postmenopausal period was divided into 5 groups, There were 18 patients within 5 years, 44 patients in 6~10 years, 134 patients in 11~15 years, 109 patients in 16~20 years and 21 patients in 21 years or older. And postmenopausal women. Bone mineral density (BMD) of the lumbar spine and femur was measured using a dual energy X-ray absorptiometry. The lowest value among lumbar spine 1, 2, 3 and 4 and the lowest value among the femoral neck, greater trochanter, total femur, and ward Values were measured. The statistical significance was analyzed by using bivariate correlation coefficient method and one - way ANOVA. In 326 patients who underwent BMD, the correlation between bone mineral density and postmenopausal BMD showed a negative correlation (-.159, p<.01) with BMD of femur and BMD of lumbar spine The correlation between the menopausal period and negative (-.208, p<.01) was shown. There was a significant difference (p<.012) between the postmenopausal femur bone density and the mean value of the lumbar spine BMD (p<.000). The relationship between bone mineral density (BMD) and postmenopausal women's postmenopausal status can be estimated by estimating the bone mineral density and using it as a basic data for osteoporosis management.