• The Journal of the Korea Contents Association
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• v.17 no.9
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• pp.99-106
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• 2017

This study focused on the issue that when a diagnostic detector is found to have a defect, a patient would be exposed to radiation and image quality would be degraded. Though dose analysis, an experiment was conducted to evaluate detector performance as Signal to Noise Ratio (SNR) and Contrast to Noise Ratio (CNR). Absorbed dose, SNR and CNR were measured using a dosimeter and a tissue equivalent phantom. The experiment was conducted to compare whether the dose value shown after being attached to the back side of the phantom matches the dose value attached behind the detector, where in the conditions of skull, chest and abdomen were set at 75 kVp, 25 mAs, 110 kVp, 8 mAs, and 80 kVp, 20 mAs, respectively. As a result, there was a difference in that the dose values attached to the back side of the detector were 0.004 mGy, 0.006 mGy, 0.003 mGy, whereas those of the back side of the phantom were 0.006 mGy, 0.016 mGy, 0.017 mGy. In order to match both values, the condition was increased and SNR and CNR also increased from 88.32, 88.10, 4.09, 1.63, 87.94, 79.97 to 93.87, 93.75, 4.91, 4.03, 92.02, 84.92. Though this study, we found that when a detector is found to have a aging, it shortens the life of equipment and increases the dose of a patient, also the improvement effect of image quality is inadequate.

• Journal of radiological science and technology
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• v.21 no.1
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• pp.35-39
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• 1998

We analyzed image factors to determine the characteristic factors that need for intelligent replenishment system of the auto film processor. We processed the serial 300 sheets of radiographic films of chest phantom without replenishment of developing and fixation replenisher. We took the digital data by using film digitizer which scaned the films and automatically summed up the pixel values of the films. We analyzed characteristic curves, average gradients and relative speeds of individual film using densitometer and step densitometry. We also evaluated the pH of developer, fixer, and washer fluid with digital pH meter. Fixer residual rate and washing effect were measured by densitometer using the reagent methods. There was no significant reduction of the digital density numbers of the serial films without replenishment of developer and fixer. The average gradients were gradually decreased by 0.02 and relative speeds were also gradually decreased by 6.96% relative to initial standard step-densitometric measurement. The pHs of developer and fixer were reflected the inactivation of each fluid. The fixer residual rates and washing effects after processing each 25 sheets of films were in the normal range. We suggest that the digital data are not reliable due to limitation of the hardware and software of the film digitizer. We conclude that average gradient and relative speed which mean the film's contrast and sensitivity respectively are reliable factors for determining the need for the replenishment of the auto film processor. We need more study of simpler equations and programming for more intelligent replenishment system of the auto film processor.

• The Journal of Korean Society for School & Community Health Education
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• v.2 no.1
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• pp.41-52
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• 2001

The purpose of this research is to plan the activation of university health business through the appraisal of the function and role of university health centers. To be more specific: Firstly, analyze the facility, personnel, health service of the health centers, Secondly, appraise the role and function of the health centers, and Thirdly, consider the activation plans of health centers. The research method taken was the study of surveys conducted and written research materials on 5 women's universities in Seoul. These materials where descriptively analyzed by converting the surveys, facility and usage of health center and current personnel status in to percentage. The major results of the research are as follows: Unlike as stated in each university's additional clause on the number of personnel were working. This lack of specialized personnel resulted into lack of specialized and various services. Medicine for external application were stocked well whereas only simple medicine for internal application were on shelf and were issued only with a doctor's prescription. Universities with a full-time doctor had various available equipments. One university conducting dental treatment was equipped with indirect chest camera, dental X-ray, unit, chair(dental treatment chair) and even supersonic, electrocardiogram were available. In the case of D women's university, the number of beds compared to the number of students was lower than that of the other 3 universities, to the total size of the university was smaller than that of the other 3 universities. Among health prevention and care matters, health consultation was the only matter practised by all universities. Uniquely, there was one university that hosted epidemic prevention business. There are various tests given by each university, with each showing many differences, but some universities did not even conduct these tests. Vaccinations were usually being conducted through commission. All universities provided basic treatment, therefore matters concerning treatment at health centers were being conducted well. Concerning the management of equipment and documents, all the matters were being conducted except one university where instead of a student medical record, they were using a daily record. Because these were women's universities, most of the educations were on women's health. The subjects of these educations included: sex, contraception, prevention and control of tuberculosis, obesity, mouth hygiene, alcohol, geriatric disease, mental health and first-aid. The rate of health center usage is growing. Being women's universities, the service and treatment practised were mostly concerning sex education.

• Journal of Chest Surgery
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• v.31 no.4
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• pp.380-387
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• 1998

We evaluated CT findings of bronchial carcinoid and accuracy of preoperative pathological diagnosis according to two subtypes. The subjects were 10 cases(typical;5, atypical;5), confirmed by surgery and tissue pathology. Sputum cytology(n=10), percutaneous aspiration(n=1) and bronchoscopic biopsy (n=8) were performed, preoperatively. The CT findings were analysed according to two subtypes. Typical carcinoid shows central location in all, and bronchial lumens just proximal to tumor were widened in two, whereas atypical carcinoid presented as peripheral leison in two. Among central atypical carcinoid, two cases showed flat meniscus appearance of lumen. Remaining one showed diffuse wall thickening. Intratumoral low density by necrosis was noted in one. Both subtypes show contrast enhancement. For preoperative diagnosis, sputum cytology & percutaneous aspiration were not conclusive at all. As for bronchoscopic biopsy, only 3 cases were accurately diagnosed as typical carcinoid. Typical carcinoid presented as endobronchial mass in all, whereas atypical carcinoid presented in various appearance. In all atypical & some typical carcinoid were misdiagnosed as primary lung cancer, preoperatively. However, in typical carcinoid, conservative surgery was possible. In conclusion, if there is discrepancy between CT findings & preoperative pathological diagnosis, full understanding of CT findings of bronchial carcinoid is imperative to choose appropriate surgical modality.

• The Journal of the Korea Contents Association
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• v.15 no.10
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• pp.362-373
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• 2015

This study analysed the effectiveness of aluminium(Al) filter in the added compound filtration for the removal of characteristic radiation from high atomic number material by DQE and image evaluation. 1mm Al was applied to each 0.1, 0.2, 0.3 mm copper and befere and after use were evaluated. Beam quality and DQE were tested by IEC regulations and image quality was evaluated by PSNR, MAE, MSE, CNR, SNR and qualitative analysis was performed by 7 items for resolution and contrast from chest x-ray criteria of national cancer checkup. MTF 10 and 50% were the same by 4.6, 2.54 cycle/mm and NPS, DQE, PSNR MAE, MSE, CNR, SNR and qualitative analysis were all the same or slightly better when Al was not used. PSNR is over 30dB and all significant and at the qualitative analysis, the p-value of t-test was over 0.05. The DQE and image quality evaluation have little difference between before and after use of Al filter and it is effective to use the Al filter for the reduction of skin dose by removal of characteristic radiation.

• Journal of Korean Medical Science
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• v.33 no.47
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• pp.292.1-292.10
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• 2018

Background: We investigated the incidence of active tuberculosis among patients with inflammatory bowel disease (IBD) treated with tumor necrosis factor (TNF) inhibitors, with or without latent tuberculosis infection (LTBI). Methods: The study was performed at a Korean tertiary referral center between January 2011 and June 2017. In total, 740 patients with IBD who underwent LTBI screening tests and were followed-up for ${\geq}1$ year after TNF inhibitor treatment initiation were enrolled. LTBI was detected on the basis of tuberculin skin test results, interferon-gamma release assay results, chest X-ray findings, and previous tuberculosis treatment history. The patients were classified into LTBI (n = 84) or non-LTBI (n = 656) group. The risk of developing tuberculosis in each group was assessed on the basis of standardized incidence ratio (SIR) and 95% confidence interval (CI) for active tuberculosis. Results: Mean patient age was 33.1 years, and patients with Crohn's disease were predominant (80.7%). Within 1 year after the initiation of TNF inhibitor treatment, 1 patient in the LTBI group (1/84; 1.2%) and 7 patients in the non-LTBI group (7/656; 1.1%) developed active tuberculosis. The overall 1-year incidence of tuberculosis among the patients was significantly higher than that among the general population (SIR, 14.0; 95% CI, 7.0-28.0), and SIR was not affected by LTBI status (LTBI group: 14.5, 95% CI, 2.0-102.6; non-LTBI group: 14.0, 95% CI, 6.7-29.4). Conclusion: Patients with IBD undergoing TNF inhibitor treatment showed a higher 1-year incidence of tuberculosis than the general population irrespective of LTBI status.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.165-171
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• 2021

To prevent the secondary hospital-acquired infection (cross-infection) from occurring in the general radiographic room in the department of radiology, the microbial measurement was conducted at the points making direct close contact with radiologists and patients. For the case of radiologists, the microbial measurement and incubation were focused on the x-ray tube handle of the radiation generating device, and, for the case of patients, the microbial measurement and incubation were focused on the chin supporting device, chest-contact point, and handle. Once disinfected with Aniosurf, the sterilized media were gathered and identified, and the microorganisms were confirmed. Based on the identification results, it was confirmed that the points making direct close contact with radiologists showed a value of 103 CFU for Proteus mirabilis, Staphylococcus epidermidis, Bacillus spp. and Candida spp., and that the points making direct close contact with patients showed a value of 103~5 CFU for Proteus mirabilis, Enterococcu faecium, Pseudomonas aeruginosa, NTM(Non-Tuberculosis Mycobacteria) and Candida spp.. It was also confirmed that the types and number of microorganisms gathered from the points making direct close contact with patients were greater. Fortunately, most of the involved microorganisms were observed to be on the skin surface and are known to become extinct when disinfected in accordance with the hospital-acquired infection control rules. However, since even minor exposure to such microorganisms may be lethal for patients with reduced immunity, caution must be taken. In particular, since the points making contact with patients showed a high level of microbial measurement, it was thought that it would be necessary for radiologists and personnel having frequent access to strictly disinfect the parts, such as instruments and handles, making frequent contact with patients. The purpose of this study was to announce the importance of safe microbial control in the radiographic inspection room in hospital, and this study is expected to be used as the baseline data for preventing hospital-acquired secondary infection and Nth infectious diseases.

• Tuberculosis and Respiratory Diseases
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• v.82 no.3
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• pp.234-241
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• 2019

Background: The utility of computed tomography (CT) in the differential diagnosis of patients with chronic obstructive pulmonary disease (COPD) exacerbation remains uncertain. However, due to the low cost associated with CT scan along with the impact of Koreas' health insurance system, there has been a rise in the number of CT scans in the patients with initial diagnosis of COPD exacerbations. Therefore, the utility of CT in the differential diagnosis was investigated to determine whether performing CT scans affect the clinical outcomes of the patients with an initial diagnosis of COPD exacerbation. Methods: This study involved 202 COPD patients hospitalized with an initial diagnosis of COPD exacerbation. We evaluated the change in diagnosis or treatment after performing a CT scan, and compared the clinical outcomes of patient groups with vs. without performing CT (non-CT group vs. CT group). Results: After performing CT, the diagnosis was changed for two (3.0%) while additional diagnoses were made for 27 of the 64 patients (42.1%). However, the treatment changed for only one (1.5%), and six patients (9.3%) received supplementary medication. There were no difference in the median length of hospital stay (8 [6-13] days vs. 8 [6-12] days, p=0.786) and intensive care unit care (14 [10.1%] vs. 11 [16.7%], p=0.236) between the CT and non-CT groups, respectively. These findings remained consistent even after the propensity score matching. Conclusion: Utility of CT in patients with acute COPD exacerbation might not be helpful; therefore, we do not recommend chest CT scan as a routine initial diagnostic tool.

• Pediatric Infection and Vaccine
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• v.29 no.2
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• pp.77-83
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• 2022

A small proportion of children with coronavirus disease 2019 (COVID-19) develop severe pneumonia. We reported the severe COVID-19 pneumonia in children aged <18 years with COVID-19 treated with remdesivir and dexamethasone from August 2021 to November 2021 by a retrospective review of their medical records. Eight children were included (5 males and 3 females). Their median age was 16 years (range: 9 to 17 years) and their median body mass index was 30.5 kg/m² (range: 22.8-38.5 kg/m²). All patients had fever and dyspnea with hypoxia. Chest radiographic findings were variable and included diffuse or multifocal consolidation, nodules, and ground-glass opacities in the lungs. After receiving intravenous remdesivir and dexamethasone, 7 of the 8 children experienced an improvement in their symptoms within 2 days. In our case series, obesity was present in 6 out of 8 children with severe COVID-19 pneumonia.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1246-1257
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• 2021

Purpose To assess the predictive factors and describe the imaging features of mediastinal lymph node (MLN) metastases in patients with head and neck cancer. Materials and Methods We compared the clinical features and disease characteristics (sex, age, site of primary tumor, histologic type, history of prior treatments, TNM stages, and metastasis in cervical LNs) of patients with head and neck cancers between the MLN metastasis and no MLN metastasis groups. We also evaluated the chest CT (distribution and maximum dimension of the largest LN) and PET/CT (maximum standardized uptake value) features of MLN metastases based on the MLN classification. Results Of the 470 patients with head and neck cancer, 55 (11.7%) had MLN metastasis, involving 150 mediastinal stations. Hypopharynx cancer, recurrent tumor, T4 stage, N2/N3 stages, and M1 stage were found to be significant predicting factors for MLN metastasis. The most common location of MLN metastasis was ipsilateral station 2 (upper paratracheal LNs, 36.4%), followed by ipsilateral station 11 (interlobar LNs, 27.3%) and ipsilateral station 10 (hilar LNs, 25.5%). Conclusion Metastasis to MLNs should be considered in patients with head and neck cancer, especially in cases that are associated with a hypopharyngeal cancer, recurrent tumor, and high TNM stages.