• Journal of radiological science and technology
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• 제33권1호
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• pp.1-10
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• 2010

Dental panoramic radiography is an imaging technique which shows the information of teeth, jaws and superficial structures on a single image. In this study, we propose the clinical dose reference for dental panoramic radiography. Dental panoramic radiography is an application which can increase the radiation does of oral cavity. It is very important to study the real condition of management for these panoramic X-ray equipments. Since there was no researches on dental panoramic equipments in domestic and foreign study groups, we measured and analyzed the dose such as effective dose, DAP and DWP of panoramic radiography.

• Journal of radiological science and technology
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• 제43권1호
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• pp.29-34
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• 2020

Mitochondria was observed much around the nuclear membrane of liver tissue where the energy metabolism process is active. Testis tissue had a large number of undifferentiated cells, and cristae in Inner membrane of Mitochondria was not observed clearly. Morphological damage occurred first in Inner membrane rather than the outer membrane. The kidney tissue was clearly observed in the form of cristae. Radiation-induced damage occurred at the edges of both ends, and the membrane was observed bursting with the thickness of the outer membrane. Small intestine cells were observed in many mitochondria in the tissues around the villus, where bowel movements were active. Morphological damage occurred with the outer and inner membranes getting tangled. Mitochondria sensitivity to radiation was sensitized in testis and small intestine tissues, and kidney, ovary and liver tissues were found to be resistant.

• Journal of Environmental Science International
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• 제14권4호
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• pp.435-444
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• 2005

A survey was conducted to 890 radiological technologists working at 44 general hospitals of 16 cities and provinces across the county to determine their stress level according to regions divided into the capital city, metropolitan areas and small- and medium-sized cities. For this purpose, such factors as their working environment, role playing, job conflict and job burden were compared and analyzed according to the regions. The findings may be summed up as follows: 1. In terms of working environment, radiological technologists in the capital city were found to have the least stress(23.46), followed by those in metropolitan areas(24.53) and small- and medium-sized cities(24.85). There was a significant difference according to the regions as for the item 'worry about influence of radioactive contamination(genetic, decisive and plausible)(P<0.001). 2. As for role playing, radiological technologists in small-and medium-sized cities appeared to receive the highest stress(l8.25) followed by metropolitan areas(l7. 71) and the capital city(l6.69). There was a statistically significant difference(P<0.001) according to the regions 3. Regarding job conflict, those who work in small- and medium-sized cities turned out to get the highest stress(15.66) compared to those in metropolitan areas(15.35) and the capital city(l4.44). In terms of job autonomy, there was no significant result from the survey in spite of the difference between metropolitan areas(14.87), small- and medium-sized cities(l4.79) and the capital city(l4.66). 4. Little difference was detected according to the regions as far as the job burden(excessive or too little) was concerned. But their was a significant regional difference in tenns of patient-related factors with the capital city(11.50), small- and medium-sized cities(l0.75), and metropolitan areas(1.63)(P<0.001).

• Journal of Radiation Industry
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• 제12권4호
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• pp.297-302
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• 2018

The wedge filter has two movements, fixed and dynamic. In this study, the depth dose distribution was analyzed to determine the stability of the dose distribution and dose volume histograms obtained by evaluating the usability of the critical normal tissue dose around the tumor dose. The depth dose was analyzed from the dose distribution from a Linac (6 MV and 10 MV irradiation field of energy $20{\times}20cm^2$, wedge filter with a SSD of 100 cm and $15^{\circ}$, $30^{\circ}$, $45^{\circ}$ Y1-in (Left -7 cm), Y2-out(Right +7 cm). To analyze the fluctuations of the depth dose, a fixed wedge and dynamic wedge toe portion was examined according to the energy and angle because the size of the fluctuations was included in the error bound and did not show significant differences. The neck, breast, and pelvic dosimetry in tumor tissue are measured more commonly with a dynamic wedge than a fixed wedge presumably due to the error range. On the other hand, dosimetry of the surrounding normal tissue is more common using a fixed wedge than with a dynamic wedge.

• Journal of radiological science and technology
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• 제41권4호
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• pp.305-312
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• 2018

The incidence of cardiovascular disease increases rapidly after 40's. The thickness of the epicardial adipose tissue was measured to analyze the risk factors affecting the thickness change. We present the cut off value for the epicardial adipose tissue thickness for high impacted variables. For the study, 547 patients underwent echocardiography, epicardial adipose tissue thickness, body mass index, abdominal subcutaneous fat thickness and diabetes mellitus were used as analytical variables. As a result, multiple regression analysis of age group showed that diabetes mellitus was highly influential in all age group, so we could predict the cut off value for the epicardial adipose tissue thickness for diabetes mellitus. As a result of ROC curve analysis, cut off value of 7.44 mm was obtained with sensitivity of 79.6% and specificity of 60.6% for diab etes variab le. Logistic regression analysis b ased on this value showed that the risk for diab etes increased 6 times with each increase in the thickness of the epicardial adipose tissue. Among the various obesity indexes, epicardial adipose tissue is used as an important index especially to prevent the risk of cardiovascular disease. Therefore, we suggest that the use of echocardiography as a routine screening method for the prevention of cardiovascular disease and metabolic syndrome, which is rapidly increasing in patients over 40's age, will enable more effective monitoring. Radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium.

• Journal of radiological science and technology
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• 제42권2호
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• pp.137-143
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• 2019

The aim of this study was analyzed the setup error of breast cancer patients in intensity modulated radiation therapy(IMRT) with deep inspiration breath holding(DIBH) and was analyzed the dose distribution due to setup error. A total of 45 breast cancer cases were performed a retrospective clinical analysis of setup error. In addition, the re-treatment planning was carried by shifting the setup error from the isocenter at the treatment. Based on this, the dose distribution of PTV and OARs was compared and analyzed. The 3D error for small breast group and medium breast group and large breast group were 3.1 mm and 3.7 mm and 4.1 mm, respectively. The difference between the groups was statistically significant(P=0.003). DVH results showed HI, CI for the PTV difference between standard treatment plan and re-treatment plan of 14.4%, 4%. The difference in $D_5$ and $V_{20}$ of the ipsilateral lung was 5.6%, 13% respectively. The difference in $D_5$ and $V_5$ of the heart of right breast cancer patients was 6.8%, 8% respectively. The difference in $D_5$, $V_{20}$ of the heart of left breast cancer patients was 7.2%, 23.5% respectively. In this study, there was a significant association between breast size and significant setup error in breast cancer patients with DIBH. In addition, it was found that the dose distribution of the PTV and OARs varied according to the setup error.

• Journal of radiological science and technology
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• 제41권5호
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• pp.451-456
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• 2018

During last a decade, there has been increased demand for 3D-printed medical devices with significant improvement of 3D-Printer (also known as Additive. Manufacturing AM), which depend upon human body features. Especially, demand for personalized medical material is highly growing with being super-aged society. In this study, 3D-reconstructed 3D mesh image from CT/MRI-images is demonstrated to analyse each patients' personalized anatomical features by using in house, then to be able to manufacture its counterpart. Developed software is distributed free of charge, letting various researcher identify biological feature for each areas.

• Journal of the Korean Society of Radiology
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• 제15권3호
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• pp.381-390
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• 2021

The purpose of this study was to examine the lecture satisfaction of radiological science majors in total remote classes due to coronavirus disease 2019, and influencing factors were analyzed. An online survey was conducted from September 1, 2020 to November 15, 2020, lecture satisfaction, teaching presence, academic motivation, self efficacy, behavior regulation and usage simplicity of remote classes for 458 3 and 4-year radiological science majors located in the Yeongnam area. Lecture satisfaction was significantly different according to grade, self-review time, and preferred teaching method. In addition, lecture satisfaction showed a significant positive corrleation with the teaching presence and usage simplicity of remote classes. In the multiple regression model, lecture satisfaction showed a significant explanatory power of 45.7% through usage simplicity, teaching presence, self efficacy and academic motivation. This study was attempted to provide basic data to increase the effect of remote classes at universities that are expected to expand in the post-corona.

• Progress in Medical Physics
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• 제27권3호
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• pp.105-110
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• 2016

Sparse angular sampling has been studied recently owing to its potential to decrease the radiation exposure from computed tomography (CT). In this study, we investigated the analytic reconstruction algorithm in sparse angular sampling using the sinogram interpolation method for improving image quality and computation speed. A prototype of the spectral CT system, which has a 64-pixel Cadmium Zinc Telluride (CZT)-based photon-counting detector, was used. The source-to-detector distance and the source-to-center of rotation distance were 1,200 and 1,015 mm, respectively. Two energy bins (23~33 keV and 34~44 keV) were set to obtain two reconstruction images. We used a PMMA phantom with height and radius of 50.0 mm and 17.5 mm, respectively. The phantom contained iodine, gadolinium, calcification, and lipid. The Feld-kamp-Davis-Kress (FDK) with the sinogram interpolation method and Maximum Likelihood Expectation Maximization (MLEM) algorithm were used to reconstruct the images. We evaluated the signal-to-noise ratio (SNR) of the materials. The SNRs of iodine, calcification, and liquid lipid were increased by 167.03%, 157.93%, and 41.77%, respectively, with the 23~33 keV energy bin using the sinogram interpolation method. The SNRs of iodine, calcification, and liquid state lipid were also increased by 107.01%, 13.58%, and 27.39%, respectively, with the 34~44 keV energy bin using the sinogram interpolation method. Although the FDK algorithm with the sinogram interpolation did not produce better results than the MLEM algorithm, it did result in comparable image quality to that of the MLEM algorithm. We believe that the sinogram interpolation method can be applied in various reconstruction studies using the analytic reconstruction algorithm. Therefore, the sinogram interpolation method can improve the image quality in sparse-angular sampling and be applied to CT applications.

• Journal of radiological science and technology
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• 제46권2호
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• pp.123-129
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• 2023

Interventional cardiology procedures can involve relatively high radiation doses compared to conventional radiography. During CAG, CAG + PCI and PCI the same area is exposed to radiation for a long period. In this study, radiation exposure data of 421 examinations in Gyeongsang area were collected, and the DRLs and ADs in actual medical practice for three types of interventional cardiology procedures in Korea were established. In CAG 286 case, 75th percentile DRLs and ADs of the total DAP were 55.89 Gy·cm² and 37.47 Gy·cm² , respectively. In CAG + PCI 92 case, those values were 222.84 Gy·cm² and 117.51 Gy·cm² respectively. In PCI 43 case, those values were 198.73 Gy·cm² and 120.13 Gy·cm² respectively. In this study, for the first time, the diagnostic reference level of interventional cardiology procedures in Gyeongsang area were established. Using the diagnostic reference level of interventional cardiology procedures derived from this study, it will help to identify and improve the level of exposure dose in the region and country.