• 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.

• Journal of the Korean Society of Radiology
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• v.16 no.2
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• pp.177-184
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• 2022

The purpose of this study is surveyed diagnostic radiography (DR) examination in veterinary hospital (VC) including non-ionization radiation such as ultra-sonography and magnetic resonance imaging. From June 1 to June 20. 2021, we surveyed the VC in 00 metropolitan city by using a structural questionnaire which are location of VC and X-ray unit et al.. Data are expressed as a mean with standard deviation for continuous variable or percent for categorical variable using SPSS ver. 26.0. As the first animal to be visited, dogs were the highest with 61.9%, followed by cats with 12.9%. In 87.1% fo cases, DR units were used, and 4 VCs did not. In 27 VCs using DR units, 48.1% separated examination room and control room, 19.8% examined in animal visited, protective clothing was in all VCs, 55.6% were measured radiation exposure dose, 92.6% was responded a necessary for examination education. From the above results, it will help to revise the guidelines for DR units and examination in korea VCs.

• Korean Journal of Radiology
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• v.23 no.4
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• pp.413-425
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• 2022

Objective: We compared appendiceal visualization on 2-mSv CT vs. conventional-dose CT (median 7 mSv) in adolescents and young adults and analyzed the undesirable clinical and diagnostic outcomes that followed appendiceal nonvisualization. Materials and Methods: A total of 3074 patients aged 15-44 years (mean ± standard deviation, 28 ± 9 years; 1672 female) from 20 hospitals were randomized to the 2-mSv CT or conventional-dose CT group (1535 vs. 1539) from December 2013 through August 2016. A total of 161 radiologists from 20 institutions prospectively rated appendiceal visualization (grade 0, not identified; grade 1, unsure or partly visualized; and grade 2, clearly and entirely visualized) and the presence of appendicitis in these patients. The final diagnosis was based on CT imaging and surgical, pathologic, and clinical findings. We analyzed undesirable clinical or diagnostic outcomes, such as negative appendectomy, perforated appendicitis, more extensive than simple appendectomy, delay in patient management, or incorrect CT diagnosis, which followed appendiceal nonvisualization (defined as grade 0 or 1) and compared the outcomes between the two groups. Results: In the 2-mSv CT and conventional-dose CT groups, appendiceal visualization was rated as grade 0 in 41 (2.7%) and 18 (1.2%) patients, respectively; grade 1 in 181 (11.8%) and 81 (5.3%) patients, respectively; and grade 2 in 1304 (85.0%) and 1421 (92.3%) patients, respectively (p < 0.001). Overall, undesirable outcomes were rare in both groups. Compared to the conventional-dose CT group, the 2-mSv CT group had slightly higher rates of perforated appendicitis (1.1% [17] vs. 0.5% [7], p = 0.06) and false-negative diagnoses (0.4% [6] vs. 0.0% [0], p = 0.01) following appendiceal nonvisualization. Otherwise, these two groups were comparable. Conclusion: The use of 2-mSv CT instead of conventional-dose CT impairs appendiceal visualization in more patients. However, appendiceal nonvisualization on 2-mSv CT rarely leads to undesirable clinical or diagnostic outcomes.

• Journal of the Korean Society of Radiology
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• v.7 no.1
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• pp.71-79
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• 2013

The purpose of this study is to establish the basic data for the management of the elderly patients aged more than 60 suffering from musculoskeletal disorders in geriatric hospitals. From January, 1 2012 to December 31, 2012, 2,500 patients who were taken the x-ray inspection and were analyzed x-ray order 5,042 cases above spines, upper lower extremities and joints. The elderly age was divided into 3 groups according to Brody elderly statistics. The majority of elderly patients who visited the hospital are exposed to spinal disorders and joint diseases. Shoulder, knee, L-spine examination cases had accounted for more than half the number of total. By age group, the number of the first quarter was most dominant commonly. Second and third quarter was maintaining slightly decrease. The fourth quarter had reduced compared to the first quarter. If the visiting purposes and the disease causes analysis and preventive measures are taken in a study, it is expected to utilize as basic data to make a plan of the education for preventing diseases and elderly behavior planning for geriatric hospitals and to redistribute health care resources of the rural areas efficiently.

• Journal of the Korean Society of Radiology
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• v.4 no.4
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• pp.25-28
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• 2010

In this paper, the fabrication and feasibility study of clinical application with euripium doped gadollium oxide ($Gd_2O_3$:Eu) nano phosphor derived by low-temperature solution combustion method. From the fabricated phosphor, the photoluminescent characteristic and linearity as a function of phosphor film thickness were investigated to evaluate x-ray converstion properties. From the experimental results, the luminescent intensity was $2945pC/cm^2$-mR at $270{\mu}m$ $Gd_2O_3$:Eu film and this value is higher 1.2 time the conventional bulk phosphor, which is possible to imaging acquisition. And good linearity was shown at x-ray exposure range for clinical diagnostic application.

• Clinical and Experimental Pediatrics
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• v.46 no.7
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• pp.655-660
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• 2003

Purpose : The relationship between chest X-ray findings and respiratory indices, including the arterial-alveolar oxygen partial pressure ratio($a/APO_2$) and the ventilatory index(VI), indicators of the clinical respiratory status in neonates with respiratory distress syndrome(RDS), was examined in the present study. Methods : The records of 50 neonates, randomly chosen from 174 neonates treated with pulmonary surfactant(PS) in the Neonatal Intensive Care Unit of Kyunghee University Hospital from 1996 to 2000 were analyzed retrospectively. Chest radiographs taken at the time after birth were classified into four groups according to Bomsel's classification. The $a/APO_2$ and VI values were calculated and compared with the corresponding chest radiographs. Results : Among the 50 cases of RDS examined, three cases were classified into grade I(6%), eight cases into grade II(16%), 20 cases into grade III(40%), and 19 cases into grade IV(38%). The mean $a/APO_2$ of the cases classified into grades I or II was 0.32 and the mean $a/APO_2$ of those classified into grades III and IV was 0.18 and 0.09, respectively. The mean VI was 0.049 for the cases classified into grades I or II and 0.076 and 0.161 for those classified into grades III and IV, respectively. Conclusion : The severity of RDS according to chest X-ray findings correlate to the values of respiratory indices, $a/APO_2$ and VI.

• The Korean Journal of Nuclear Medicine
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• v.16 no.2
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• pp.63-70
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• 1982

To evaluate the diagnostic usefulness and significance of quantitative sacroiliac joint scintigraphy in the assessment of sacroiliitis, we measured Sacroiliac Joint/Sacrum Uptake Ratio(SIS Ratio) by region of interest(ROI) method using $^{99m}Tc-methylene$ diphosphonate. The observed results were as follows: 1. Using ROI method, the SIS ratios for the control group of 65 persons were $1.05{\pm}0.08$(left) and $1.06{\pm}0.07$(right) which were narrower in range than those of slice method $(mean{\pm}S.D.)$. 2. The effects of age, gender and laterality on SIS ratio were not significant. 3. In left side, one of 6 patients with rheumatoid arthritis had SIS ratio in excess of 2 standard deviation of normal control group, and remainder had SIS ratios within normal limit. In right side, 3 patients had SIS ratios in excess of 2 standard deviation of normal control group, and remainder, within normal limit. 4. In both sacroiliac joint, 2 of 3 patients having sacroiliitis clinically with Reiter's syndrome whose pelvis A-P X-ray findings showed normal had high SIS ratios (left/right; 1.31/1.69, 1.90/1.80), but SIS ratio of one patient who had no evidence of sacroiliitis clinically was within normal limit. 5. In 6 patients with ankylosing spondylitis in both sacroiliac joints, 4 whose pelvis A-P Xray findings showed severe sclerotic change of sacroiliac joints had SIS ratio within normal limit or below that of normal control group, and SIS ratios of 2 patients whose pelvis A-P X-ray findings showed were increased. 6. 4 of 5 patients with low back pain of which cause could not be evaluated clinically and radiologically had SIS ratios in excess of that of normal control group. It would be concluded that quantitative sacroiliac joint scintigraphy is useful and sensitive screening method in the diagnosis as well as in the assessment clinical activity of sacroiliitis.

• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.204-210
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• 2013

The patients who had been operated total mastectomy are different from general women in their breasts thickness due to breast surgery. As a result, digital chest image from total mastectomy patients will be different attenuation. The main objective for this study is to show that a proper Ion chamber standard combination measuring MTF which is objective basis for Digital image, when be x-ray for total mastectomy patient. We have designed the unique number that shown Left is 1, Right is 2, Center is 3 and have put the edge phantom on detector ion chamber. Lastly, we have obtained experiment images. The evaluations of all image quality have measured by 50% MTF of spatial resolution and absorption dose using Matlab(R2007a). The result showed that average exposure condition, MTF value, absorption dose for 1+3 and 2+3 combinations were 2.745 mAs, 1.925 lp/mm, 0.688 mGy. Consequently, that showed high MTF, DQE and low dose than other combinations. Therefore, a proper changes of ion chambers are able to improve image quality and to reduce radiation exposure when be X-ray for total mastectomy patients. Also, it will be possible to standard for application chamber combination and utilization on clinical detection.

• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.334-341
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• 1992

A clinical review of 34 cases of aortic dissection which were admitted to Yeungnam University hospital between March 1983 and April 1992. The results are as follows : 1. The peak incidence was in 5th, 6th decade and male to female ratio was 1.83 : 1. 2. The most common cause of aortic dissection was atherosclerosis and hypertension(79%). 3. The most common presenting symtom was pain(73%), but dyspnea, palpable mass, murmur, shock were also observed. 4. Abnormal electrocardiographic finding was myocardial ischemia in 6 cases, arrythmia in 5 cases, LVH in 5 cases. 5. The X-ray findings showed abnorma aortic conture in 10 cases but normal X-ray finding was observed in 63% of DeBaKey Type III. 6. The most common diagnostic procedure was echocardiogram and abdominal ultrasonography. 7. The mortality of all cases was 20%, operation mortality was 18% but no death of medically treatment in medical indication.

• Economic and Environmental Geology
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• v.33 no.5
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• pp.391-404
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• 2000

This study investigated the geochemical characteristics of mine drainage discharged from an abandoned coal mine in the Hwasoon area. Surface water samples were collected from 23 locations along the Hancheon creek. The concentration of Zn and Cu in stream waters was highest at low pH (3.53), whereas the content of TDS and TDI was highest at high pH (7.78) due to the concentration of Ca, $HCO_3$ and $SO_4$. At the upstream site, the Ba, Fe, Mn, Zn, and $SO_4$ contents were relatively high but decreased significantly with the distance from the coal mine. On the contrary, the Na and $NO_3$ contents were low at the upstream site but increased downstream. Yellow precipitate material collected in the Hancheon consisted mainly of iron and LOI. This yellow precipitate was heated from 100 to $900^{\circ}C$ for 1 hour. With increasing temperature, the intensity of hematite peaks were sharply produced in X-ray pattern and the absorption band Fe-O of hematite increased in IR due to dehydration and melting. The yellow to brown precipitate and evaporite materials were collected by a air-dry from the acid mine water at the laboratory. After drying, the concentration of ions in the acid water samples increased progressively in oversaturation with respect to either gypsum, ferrohexahydrite or quenstedetite. The X-ray powder diffraction studies identified that the precipitated and evaporated materials after drying were well crystallized gypsum, ferrohexahydrite and quenstedetite. Diagnostic peaks used for identification of gypsum were the 7.65, 4.28, 3.03, 2.87 and 2.48$\AA$ peaks and those for ferrohexahydrite were the 5.46, 5.12, 4.89, 4.44, 4.05, 3.62, 3.46, 3.40, 3.20, 3.03, 2.94, 2.53, 2.28, 2.07, 1.88 and 1.86${\AA} peaks. The IR spectra with OH-stretching, deformation of $H_2O$and ${SO_4}^{2-}$stretching vibration include the existence of gypsum, ferrohexahydrite and quenstedetite in the precipitated and evaporite materials. In the SEM and EDS analysis for the evaporite material, gypsum with well-crystallized, acicular, and columnar form was distinctly observed.