• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.26-32
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• 2014

Purpose: As PET-MRI which has excellent soft tissue contrast is developed as integration system, many researches about clinical application are being conducted by comparing with existing display equipments. Because PET-MRI is actively used for head and neck cancer diagnosis in our hospital, lymph node metastasis before the patient's surgery was diagnosed and clinical usefulness of head and neck cancer PET-MRI scan was evaluated using pathological opinions and idiopathy surrounding tissue metastasis evaluation method. Materials and Methods: Targeting 100 head and neck cancer patients in SNUH from January to August in 2013. $^{18}F-FDG$ (5.18 MBq/kg) was intravenous injected and after 60 min of rest, torso (body TIM coil, Vibe-Dixon) and dedication (head-neck TIM coil, UTE, Dotarem injection) scans were conducted using $Bio-graph^{TM}$ mMR 3T (SIEMENS, Munich). Data were reorganized using iterative reconstruction and lymph node metastasis was read with Syngo.Via workstation. Subsequently, pathological observations and diagnosis before-and-after surgery were examined with integrated medical information system (EMR, best-care) in SNUH. Patient's diagnostic information was entered in each category of $2{\times}2$ decision matrix and was classified into true positive (TP), true negative (TN), false positive (FP) and false negative (FN). Based on these classified test results, sensitivity, specificity, accuracy, false negative and false positive rate were calculated. Results: In PET-MRI scan results of head and neck cancer patients, positive and negative cases of lymph node metastasis were 49 and 51 cases respectively and positive and negative lymph node metastasis through before-and-after surgery pathological results were 46 and 54 cases respectively. In both tests, TP which received positive lymph node metastasis were analyzed as 34 cases, FP which received positive lymph node metastasis in PET-MRI scan but received negative lymph node metastasis in pathological test were 4 cases, FN which received negative lymph node metastasis but received positive lymph node metastasis in pathological test was 1 case, and TN which received negative lymph node metastasis in both two tests were 50 cases. Based on these data, sensitivity in PET-MRI scan of head and neck cancer patient was identified to be 97.8%, specificity was 92.5%, accuracy was 95%, FN rate was 2.1% and FP rate was 7.00% respectively. Conclusion: PET-MRI which can apply the acquired functional information using high tissue contrast and various sequences was considered to be useful in determining the weapons before-and-after surgery in head and neck cancer diagnosis or in the evaluation of recurrence and remote detection of metastasis and uncertain idiopathy cervical lymph node metastasis. Additionally, clinical usefulness of PET-MRI through pathological test and integrated diagnosis and follow-up scan was considered to be sufficient as a standard diagnosis scan of head and neck cancer, and additional researches about the development of optimum MR sequence and clinical application are required.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.3
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• pp.171-175
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• 2008

Purpose: There have been something difficulties in locating focuses and quantitative analysis in case of pediatric patients because of the relatively small body compared to adults. This author of this study, therefore, evaluated the usefulness of DFOV (Display Field Of View) according to its changes in PET/CT image reconstruction by means of the phantom experiment and pediatric patients examination. Materials & Methods: 0.023 MBq/cc of $^{18}F$-FDG was put into the uniform NU2-94 phantom, and then emission scan was acquired for 10 minutes. For reconstruction, DFOV values were changed to 50, 45, 40, 35, 30, and 25 cm respectively. As for patient images, 20 patients who were diagnosed as the one or suspicion of the children tumor are targeted from Oct 2007 to Jan 2008. For image reconstruction, 50 cm was the basis of DFOV, and the value was adjusted to DFOV 45 cm to 25 cm respectively. In the phantom and the reconstruction image of pediatric patients, the changes in pixel size and $SUV_{max}$ according to DFOV changes were analyzed. Results: As DFOV decreased to 50, 45, 40, 35, 30, and 25 cm by means of the phantom, the pixel size was changed to 3.906, 3.515, 3.125, 2.734, 2.343, and 1.953 mm respectively. Besides, as a result of reconstruction DFOV in images of pediatric patients to 50, to 25 cm, the different values of $SUV_{max}$ are shown as 3.3, 7.3, 12, 14, 18% and 2.6, 4.3, 5.0, 7.0, 10.0% on respectively when 50 cm was the standard. Conclusion: In $SUV_{max}$ using the phantom, as DFOV decreased every 5 cm, the mean value gradually increased. With 50 cm as the standard, the increase rates were 3.7, 6.5, 11.2, 19.5, and 32.1% respectively. As for pediatric patients image too, as DFOV decreased, the rates increased as in the phantom experiment. In image reconstruction, since DFOV decrease regardless of matrix size change reduced the pixel size, the image quality can be improved. This would be more useful than reconstruction and enlarge images of pediatric patients in the same way of examining adults. However, when the value of 35 cm DFOV was applied, this may result in truncated artifact, and thus the application should be properly controlled. Change of DFOV may produce better image for pediatric patients, but changes of SUV values according to DFOV change should be considered in reading.

• Journal of Chest Surgery
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• v.41 no.1
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• pp.74-81
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• 2008

Background: Fascin is an actin-bundling protein that induces membrane protrusions and it increases cell motility in various transformed cells. Esophageal cancer is one of the most lethal malignancies, and it exhibits extensive local invasion or frequent regional lymph node metastasis even after curative surgery. We investigate the expression of fascin by performing immunohistochemistry to evaluate the clinical characteristics and prognostic significance of its expression in esophageal cancer patients. Material and Method: Immunochemistry for fascin was performed on 76 tumor samples from 76 patients who underwent esophageal cancer operations. The expression levels of fascin in the 76 esophageal cancer tissues were compared with those in the corresponding normal esophageal epithelium. The fascin-positive samples were defined as those showing more than 75% of fascin-positive cells. Result: Overall, a fascin positive expression was detected in 39 (51.3%) out of the total 76 cases. The tumors with positive fascin expression tended to more frequently show a higher stage (p=0.030), and a higher T-factor (p=0.031). The prognosis of the fascin negative group was significantly better than that of the fascin positive group (p=0.004). Multivariate analysis revealed that lymphovascular invasion and the fascin expression were independent prognostic factors. Conclusion: Fascin was expressed in 513% of the esophageal cancer tissues and a positive expression of fascin was associated with more advanced tumor progression and recurrence. Our study suggests that the fascin expression may be an independent prognostic factor for an unfavorable clinical course few those patients suffering with esophageal cancer.

• Journal of Radiation Protection and Research
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• v.23 no.3
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• pp.123-138
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• 1998

Characteristics of element responses of Panasonic UD802 personnel dosimeters in the X, ${\beta}$, ${\gamma}$, ${\gamma}/X$, ${\gamma}/{\beta}$ and ${\gamma}$/neutron mixed fields were assessed. A dose-response algorithm has been developed to decide the high probability of a radiation type and energy by using the distribution in all six ratios of the multi-element TLD. To calculate the 4-element response factors and ratios between the elements of the Panasonic TLDs in the X, $\beta$, and $\gamma$ radiation fields, Panasonic’s UD802 TLDs were irradiated with KINS’s reference irradiation facility. In the photon radiation field, this study confirms that element-3 (E3) and element-4 (E4) of the Panasonic TLDs show energy dependent both in low- and intermediate-energy range, while element-1 (E1) and element-2 (E2) show little energy dependency in the entire whole range. The algorithm, which was developed in this study, was applied to the Panasonic personnel dosimetry system with UD716AGL reader and UD802 TLDs. Performance tests of the algorithm developed was conducted according to the standards and criteria recommended in the ANSI N13.11. The sum of biases and standard deviations was less than 0.232. The values of biases and standard deviations are distributed within a triangle of a lateral value of 0.3 in the ordinate and abscissa, With the above algorithm, Panasonic TLDs satisfactorily perform optimum dose assessment even under an abnormal response of the TLD elements to the energy imparted. This algorithm can be applied to a more rigorous dose assessment by distinguishing an unexpected dose from the planned dose for the most practical purposes, and is useful in conducting an effective personnel dose control program.

• Tuberculosis and Respiratory Diseases
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• v.55 no.5
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• pp.499-505
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• 2003

Background : The brain is a common site of a metastasis in lung cancer patients. If left untreated, the patients succumb to progressive neurological deterioration with a lower survival rate than with other metastases sites. Contrast-enhanced MR imaging in the absence of symptoms or clinical signs is not recommended for identifying a cerebral metastasis in lung cancer patients because of management effectiveness. This pilot study was performed to estimate whether or not limited brain MR imaging, which has a lower cost, could be used to replace conventional brain MR imaging. Method : Between April 1999 and March 2001, 43 patients with a primary lung cancer and the others (breast cancer, stomach cancer, colon cancer, malignant melanoma etc), who had neurological symptoms and signs, were examined using conventional brain MR imaging to examine brain metastases. The control group involved four patients who had no evidence of brain metastases the sensitivity, specificity and correlation of limited brain MR imaging were compared with conventional brain MR imaging. Results : All the 43 patients who were examined with conventional brain MR imaging showed evidence of brain metastases, whereas limited brain MR imaging indicated that 42 patients had brain metastases(sensitivity=97.67%). One patient in whom limited brain MR imaging showed no brain metastasis had a metastasis in the cerebellum, as shown by the contrast-enhanced T1 weighted axial view using conventional brain MR imaging. The conventional brain MR imaging and the limited brain MI imaging of the 4 control patients both indicated no brain metastases (specificity=100 %). The Pearson Correlation of the two groups was 0.884(Confidence Interval : 99%) observed. Conclusion : Limited brain MR imaging can detect a brain metastasis with the same accuracy. In addition, it is cost-effective (229,000 won, 180$) compared to conventional brain MR imaging(529,000 won, 480$) when patients had neurological symptoms and signs or staging.

• Tuberculosis and Respiratory Diseases
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• v.62 no.1
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• pp.5-10
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• 2007

Background: Korean national guidelines for examining contacts with active pulmonary tuberculosis (TB) are a tuberculin skin test (TST) and chest radiographs. The treatment of a latent TB infection as performed only in those younger than six years of age who test positive for TST. Although there is a high incidence of active TB in young Korean soldiers, the current national guidelines for controlling contacts with active TB in soldiers are insufficient. This study highlights the problems with the Korean guidelines for controlling a TB outbreak in a small military unit. Material and Methods: In December of 2005, there was a tuberculosis outbreak in a military unit with a total of 464 soldiers in Kyung Gi province. The chest radiographs were taken of all the soldiers, and TST were carried out on 408 candidates. Results: In the first screening of the chest radiographs, two active TB patients were detected. By August of 2006, four additional cases were detected, making a total of six cases after the outbreak. All the patients showed active pulmonary TB or TB pleuritis. When the results of TST in the close contacts and non-close contacts were compared, there was a significant difference in the absolute size of the induration($9.70{\pm}7.50mm$ vs. $6.26{\pm}7.02mm$, p<0.001) as well as the ratio of patients showing an induration > 10mm (50.0% vs. 32.0%, p<0.001) and 15mm (33.2% vs. 20.9%, p= 0.005). Conclusion: Although the national guidelines for managing a TB outbreak in a military unit were followed, there were continuous instances of new active TB cases. This highlights the need for new guidelines to prevent the spread of TB.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.1
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• pp.77-84
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• 2020

This study is apply 3D spatial information per traditional landscape space by comparing spatial information data created using a small drone and 3D scanner used for 3D spatial information construction for efficient preservation and management of traditional landscaping space composed of areas such as scenic sites and traditional landscape architectures. The analysis results are as follows. First, aerial photogrammetry data is less accurate than 3D scanners, but it was confirmed to be more suitable for monitoring landscape changes by reading RGB images than 3D scanners by texture mapping using digital data in constructing orthographic image data. Second, the orthographic image data constructed by aerial photogrammetry in a traditional landscaping space consisting of a fixed area, such as Gwanghalluwon Garden, produced visually accurate and precise results. However, as a result of the data extraction, data for trees, which is one of the elements that make up the traditional landscaping, was not extracted, so it was determined that 3D scanning and aerial surveying had to be performed in parallel, especially in areas where trees were densely populated. Third, The surrounding trees in Soswaewon Garden caused many errors in 3D spatial information data including topographic data. It was analyzed that it is preferable to use 3D scanning technology for precise measurement rather than aerial photogrammetry because buildings, landscaping facilities and trees are dense in a relatively small space. When 3D spatial information construction data for a traditional landscaping space composed of area using a small drone and a 3D scanner free from temporal and spatial constraints and compared the data was compared, the aerial photogrammetry is effective for large site such as Hahoe Village, Gyeongju and construction of a 3D space using a 3D scanner is effective for traditional garden such as Soswaewon Garden.

• The korean journal of orthodontics
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• v.40 no.5
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• pp.304-313
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• 2010

Objective: The aim of this study was to evaluate the occlusal force and contact area and to find its associating factors in Koreans. Methods: Occlusal force and contact area in maximum intercuspation were measured using the Dental $Prescale^{(R)}$ system in 651 subjects (15 with normal occlusion, 636 with various malocclusions divided into subgroups according to the skeletal pattern, Angle's molar relationship, age and gender). Results: Occlusal force of the normal occlusion group ($744.5{\pm}262.6N$) was significantly higher than those of the malocclusion group ($439.0{\pm}229.9N$, $p$ < 0.05). Occlusal force was similar regardless of differences in ANB angle or Angle's molar classification, however the increase in vertical dimension significantly reduced occlusal force ($p$ < 0.05). Conclusions: Occlusal force was significantly lower in the malocclusion group compared to the normal occlusion group, and in females compared to males, but it was not affected by age, antero-posterior skeletal pattern or molar classification. Although a hyperdivergent facial pattern indicated lower occlusal force compared to a hypodivergent facial pattern, the differences in skeletal pattern were not the primary cause of its decrease, but a secondary result induced by the differences in occlusal contact area according to the facial pattern.

• Progress in Medical Physics
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• v.14 no.2
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• pp.108-123
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• 2003

The purpose of this study is to evaluate the contribution of $^{18}$ F-FDG brain PET in the differentiating Idiopathic parkinson's diesease (IPD), progressive supranuclear palsy (PSP), and multiple system atrophy (MSA). We studied 24 patients with parkinsonism : 8 patients (mean age 67.9$\pm$10.7 y: M/F : 3/5) with IPD, 9 patients (57.9$\pm$9.2 y : M/F : 4/5) with MSA and 7 patients (67.6$\pm$4.8 y : M/F 3/4) with PSP. All patients with parkinsonism and 22 age-matched normal controls underwent $^{18}$ F FDG PET in 3D mode after the injection of 370 MBq $^{118}$ F FDG. The patients with IPD, MSh and PSP were compared with a normal control group by a two-sided t-test of SPM99 (uncorrected P<0.001, extent threshold>100 voxel). All three parkinsonism groups, showed significant hypometabolism in the cerebral neocortex compared to the normal control group. However, the three groups displayed different metabolism in the subcortical structure, brain stem, and cerebellum. In IPD, there was no significant hypometabolism in the putamen, brain stem and cerebellum. However, MSA patients showed significant hypometabolism in the striatum, pons, and cerebellum compared to the normal controls and IPD patients. In addition, PSP showed significant hypometabolism in the caudate nuclei, the thalamus, midbrain, and the cingulate gyrus compared to the normal controls, the IPD, and MSA groups (IPD vs Normal sensitivity/specificity : 75%/l00%, MSA vs Normal sensitivity/specificity :100%/87%, PSP vs Normal sensitivity/specificity : 86%/94%). Our results show that the regional metabolism of IPD, MSA, and PSP is different mainly in the striatum, thalamus, brain stem and cerebellum. An assessment of the $^{18}$ F-FDG PET scan images using SPM may be a useful adjunct to a clinical examination in making a differential diagnosis of Parkinsonism.

• Geophysics and Geophysical Exploration
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• v.9 no.3
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• pp.207-224
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• 2006

It has been widely known that the seismic piezo-cone penetration test (SCPTu) is one of the most useful techniques for investigating the geotechnical characteristics such as static and dynamic soil properties. As practical applications in Korea, SCPTu was carried out at two sites in Busan and four sites in Incheon, which are mainly composed of alluvial or marine soil deposits. From the SCPTu waveform data obtained from the testing sites, the first arrival times of shear waves and the corresponding time differences with depth were determined using the cross-over method, and the shear wave velocity $(V_S)$ profiles with depth were derived based on the refracted ray path method based on Snell's law. Comparing the determined $V_S$ profile with the cone tip resistance $(q_t)$ profile, both trends of profiles with depth were similar. For the application of the conventional CPTu to earthquake engineering practices, the correlations between $V_S$ and CPTu data were deduced based on the SCPTu results. For the empirical evaluation of $V_S$ for all soils together with clays and sands which are classified unambiguously in this study by the soil behavior type classification index $(I_C)$, the authors suggested the $V_S-CPTu$ data correlations expressed as a function of four parameters, $q_t,\;f_s,\;\sigma'_{v0}$ and $B_q$, determined by multiple statistical regression modeling. Despite the incompatible strain levels of the downhole seismic test during SCPTu and the conventional CPTu, it is shown that the $V_S-CPTu$ data correlations for all soils, clays and sands suggested in this study is applicable to the preliminary estimation of $V_S$ for the soil deposits at a part in Korea and is more reliable than the previous correlations proposed by other researchers.