• Imaging Science in Dentistry
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• v.34 no.3
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• pp.151-157
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• 2004

Purpose : To evaluate the quantitative accuracy of three-dimensional (3D) images by means of comparing distance measurements on the 3D images with direct measurements of dry human skull according to slice thickness and scanning modes. Materials and Mathods : An observer directly measured the distance of 21 line items between 12 orthodontic landmarks on the skull surface using a digital vernier caliper and each was repeated five times. The dry human skull was scanned with a Helical CT with various slice thickness (3, 5, 7 mm) and acquisition modes (Conventional and Helical). The same observer measured corresponding distance of the same items on reconstructed 3D images with the internal program of V-works 4.0/sup TM/(Cybermed Inc., Seoul, Korea). The quantitative accuracy of distance measurements were statistically evaluated with Wilcoxons' two-sample test. Results: 11 line items in Conventional 3 mm, 8 in Helical 3mm, 11 in Conventional 5mm, 10 in Helical 5mm, 5 in Conventional 7mm and 9 in Helical 7mm showed no statistically significant difference. Average difference between direct measurements and measurements on 3D CT images was within 2mm in 19 line items of Conventional 3mm, 20 of Helical 3mm, 15 of Conventional 5mm, 18 of Helical 5mm, II of Conventional 7mm and 16 of Helical 7mm. Conclusion: Considering image quality and patient's exposure time, scanning protocol of Helical 5mm is recommended for 3D image analysis of the skull in CT.

• Imaging Science in Dentistry
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• v.36 no.2
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• pp.89-94
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• 2006

Purpose : To evaluate clinical usefulness of facial soft tissue thickness measurement using 3D computed tomographic images. Materials and Methods : One cadaver that had sound facial soft tissues was chosen for the study. The cadaver was scanned with a Helical CT under following scanning protocols about slice thickness and table speed; 3 mm and 3 mm/sec, 5 mm and 5 mm/sec, 7 mm and 7 mm/sec. The acquired data were reconstructed 1.5, 2.5, 3.5 mm reconstruction interval respectively and the images were transferred to a personal computer. Using a program developed to measure facial soft tissue thickness in 3D image, the facial soft tissue thickness was measured. After the ten-time repeation of the measurement for ten times, repeated measure analysis of variance (ANOVA) was adopted to compare and analyze the measurements using the three scanning protocols. Comparison according to the areas was analyzed by Mann-Whitney test. Results : There were no statistically significant intraobserver differences in the measurements of the facial soft tissue thickness using the three scanning protocols (p>0.05). There were no statistically significant differences between measurements in the 3 mm slice thickness and those in the 5 mm, 7 mm slice thickness (p>0.05). There were statistical differences in the 14 of the total 30 measured points in the 5 mm slice thickness and 22 in the 7 mm slice thickness. Conclusion : The facial soft tissue thickness measurement using 3D images of 7 mm slice thickness is acceptable clinically, but those of 5 mm slice thickness is recommended for the more accurate measurement.

• Tuberculosis and Respiratory Diseases
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• v.81 no.2
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• pp.123-131
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• 2018

Background: Chronic obstructive pulmonary disease (COPD) may cause changes in the shape of the thoracic cage by increasing lung volume and hyperinflation. This study investigated changes in thoracic cage dimensions and related factors in patients with COPD. Methods: We enrolled 85 patients with COPD (76 males, 9 females; mean age, $70.6{\pm}7.1years$) and 30 normal controls. Thoracic cage dimensions were measured using chest computed tomography at levels 3, 6, and 9 of the thoracic spine. We measured the maximal transverse diameter, mid-sagittal anteroposterior (AP) diameter, and maximal AP diameter of the right and left hemithorax. Results: The average AP diameter was significantly greater in patients with COPD compared with normal controls ($13.1{\pm}2.8cm$ vs. $12.2{\pm}1.13cm$, respectively; p=0.001). The ratio of AP/transverse diameter of the thoracic cage was also significantly greater in patients with COPD compared with normal controls ($0.66{\pm}0.061$ vs. $0.61{\pm}0.86$; p=0.002). In COPD patients, the AP diameter of the thoracic cage was positively correlated with body mass index (BMI) and 6-minute walk test distance (r=0.395, p<0.001 and r=0.238, p=0.028) and negatively correlated with increasing age (r=-0.231, p=0.034). Multiple regression analysis revealed independent correlation only between BMI and increased ratio of AP/transverse diameter of the thoracic cage (p<0.001). Conclusion: Patients with COPD exhibited an increased AP diameter of the thoracic cage compared with normal controls. BMI was associated with increased AP diameter in these patients.

• Journal of Radiation Protection and Research
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• v.30 no.4
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• pp.209-219
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• 2005

This study was carried out to examine the effect of the DNA repair inhibitors, Cytosine Arabinoside(Ara C), 3-Aminobenzamide(3AB) and Hydroxyurea(HU) on the frequencies of radiation-induced micronuclei(MNi) and aneuploidy. Irradiated lymphocytes(1-3Gy) were treated with DNA repair inhibitors, Ara C, 3AB and HU for 3 hours and CBMN assay - FISH technique with DNA probe for chromosome 1 and 4 was performed. The frequencies of x-ray induced MNi and aneuploidy of chromosome 1 and 4 were increased in a dose-dependent manner. Ara C, 3AB and HU enhanced the frequencies of radiation-induced MNi and the frequencies of radiation-induced aneuploidy of chromosome 1 and 4 were enhanced by HU and Ara C while no effect was observed by 3AB. The frequency of radiation-induced aneuploidy of chromosome 1 was higher than that of chromosome 4. These results suggest that there are different mechanisms involved in the formation of MNi and aneuploidy by radiation.

• Journal of Korean society of Dental Hygiene
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• v.4 no.1
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• pp.15-29
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• 2004

The purpose of this study was to understand the relationship among knowledge, attitude, and behavior of dental personnel about the defense against dental radiation according to general features, and help them recognize the importance of defense against dental radiation. A questionnaire survey of 187 dental personnel who were working in 121 medical institutions such as university hospitals, general hospitals, hospitals, clinics, and public health centers in Seoul area was conducted from December 2002 to January 2003. Study findings are as follows: 1. The average knowledge score for the defense of radiation was 9.51(full score=14): By the demographic features, the know level for the defense of radiation was appeared to be different with the occupational category, age, academic background, workplace, year of working, and whether having the education of radiation or not. By questionnaire items, the knowledge for the defense of radiation was high in general, but for the item. 'the average amount of being bombed with radiation according occupations cannot be over 20mSv in a year for prescribed 5 years'. it was 18.7%: and for the item. 'the longer the length between focus and film. the less the amount of skin exposure', it was 40.6%. showing less knowledge for these two items. 2. The average attitude score for the defense of radiation was 64.24 (full score=75): By the demographic features, the attitude score was higher with respondents who were 31-35 years old. 11-15 years of working. and having radiation education. The attitude score by questionnaire items was generally high for all the items. 3. The average behavior score for the defense of radiation was 45.43: (a) By the demographic features, the behavior score for the defense of radiation was appeared to be higher with respondents who were dentists for occupational category, the aged for age, holding higher diploma for academic background, working in the university hospitals for workplace, and having longer occupational career for the year of working. (b) The behavior score for the defense of radiation by questionnaire items was lower than that of the attitude score for all the items. For the item, 'the amount of X-ray radiation is adjusted according to such conditions as patients' age, radiating areas, and kind of films', the score was 4.03; and for the item, 'Must receive the education of safety management of radiation periodically', the score was 1.73 and it was the lowest one. 4. As for the correlation among the knowledge, attitude, and behavior for the defense of radiation, the higher the level of knowledge and attitude, the higher the level of behavior.

• 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.

• Radiation Oncology Journal
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• v.19 no.3
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• pp.293-299
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• 2001

Prupose : LiF TLD has a problem to be used in vivo dosimetry because of the toxic property of LiF. The aim of this study is to develop new dosimeter with LiF TLD to be used in vivo dosimetry. Materials and methods : We designed and manufactured the teflon box(here after TLD holder) to put TLD in. The external size of TLD holder is $4\times4\times1\;mm^3$ To estimate the effect of TLD holder on TLD response for radiation, the linearity of TLD response to nominal dose were measured for TLD in TLD holder. Measurement were peformed in the 10 MV x-ray beam with LiF TLD using a solid water phantom at SSD of 100 cm. Percent Depth Dose (PDD) and Tissue-Maximum Ratio (TMR) with varying phantom thickness on TLD were measured to find the effect of TLD holder on the dose coefficient used for dose calculation in radiation therapy. Results : The linearity of response of TLD in TLD holder to the nominal dose was improved than TLD only used as dosimeter And in various measurement conditions, it makes a marginnal difference between TLD in TLD holder and TLD only in their responses. Conclusion : It was proven that the TLD in TLD holder as a new dosimetry could be used in vivo dosimetry.

• Archives of Hand and Microsurgery
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• v.23 no.4
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• pp.254-261
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• 2018

Purpose: Favorable results have been reported after the direct repair of chronic ulnar collateral ligament ruptures of the thumb metacarpophalangeal (MP) joint, but the results for radial ligament seem rather controversial. The purpose of this study is to compare the results of ligament reattachment between chronic rupture of the ulnar and the radial collateral ligament (RCL) of the joint. Methods: We reviewed retrospectively the radiologic and clinical results of ligament reattachment with suture anchors for chronic (more than 6 weeks) rupture of the collateral ligament of the thumb MP joint with averaged 22-month follow-up. The data between 6 radial and 8 ulnar ligament repairs were compared statistically. Results: The average of postoperative ulnar deviation angle was $13.3^{\circ}$ in radial ligament and $2.0^{\circ}$ in ulnar ligament (p=0.020) in the last follow-up plain X-ray. Postoperative ligament instability was positive in 4 out of the 6 radial repairs and no case with instability was observed in ulnar ligament. In postoperative follow-up, sustained joint subluxation was observed only in 2 out of the 6 radial repairs. Conclusion: The delayed repair of the RCL of the thumb MP joint resulted in less favorable outcomes and ligament instability was observed postoperatively in more than half of the cases.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.445-454
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• 2019

Layered double hydroxides (LDHs) nanoparticles have emerged as novel nanomaterials for bio-imaging applications due to its unique layered structure, physicochemical properties, and good biocompatibility. Bio-imaging is one of the most important fields for medical applications in clinical diagnostics and therapeutics of various diseases. Enhanced diagnostic techniques are needed to realize new paradigm for next-generation personalized medicine through nanoscale materials. When nanotechnology is introduced into bio-imaging system, nanoparticle probes can endow imaging techniques with enhanced ability to obtain information about biological system at the molecular level. In this review, we summarize structural features of LDH nanoparticles with current issues of bio-imaging system. LDH nanoparticle probes are also discussed through in vitro as well as in vivo studies in various bio-imaging techniques including fluorescence imaging, magnetic resonance imaging (MRI), positron emission tomography (PET), and computed X-ray tomography (CT), which will have the potential in the development of the advanced nanoparticles with high sensitivity and selectivity.

• 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.