• Journal of Veterinary Clinics
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• v.26 no.1
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• pp.104-108
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• 2009

Global cerebral ischemia occurs commonly in patients who have a variety of clinical conditions including cardiac arrest and shock. Cerebral ischemia results in a rapid depletion of energy stores that triggers resulting in excitotoxic death. Imaging studies of the brain with computed tomography(CT) or magnetic resonance imaging(MRI) are necessary to confirm the clinical neurolocalization, identify any associated mass effect, and rule out other causes of focal brain disorders. Cardiopulmonary arrest was occurred by propofol anesthesia in a 1 year old, intact female Beagle dog. After successful cardiopulmonary resuscitation was performed within 5 minutes, clinical signs such as vocalization, paddling, opisthotonus and seizure were represented. At the 12th day, CT and MRI examinations of the brain were performed to evaluate the brain. After euthanasia, histopathologic examination was performed. On transverse image of CT, lesions appeared as a hypodense in the right dorsal surface of the frontal lobe and level of optic canal, and dorsomedial surface of occipital lobe of cerebrum. No contrast enhancement was represented following intravenous contrast administration. On MR images of brain, the lesions were seen as a hyperintense on T2-weighted(T2W) images and a isointense or mild hypointense on T1-weighted(T1W) images. Hyperintense lesions both T2W and T1W images were observed at the surrounding cerebral sulcus. There was no significant signal changes on contrast T1WI. Histopathologic examination after euthanasia revealed that the lesion was necrosis of the cerebral cortex caused by cerebral ischemia.

• Journal of Sericultural and Entomological Science
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• v.46 no.2
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• pp.77-79
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• 2004

To investigate whether BF-7, extracted from Bombyx mori, improved learning and memory of ordinary people, K-WAIS (Korean version of Wechsler adult intelligence scale) was performed in 4 normal students. Treatment with 400 mg of BF-7 increased mean IQ from 103 to 114. To know how BF-7 plays such a positive role, we measured the blood flow to brain, especially for the area concerned with learning and memory, with Single Photon Emission Computed Tomography(SPECT). Our result showed that the blood flow to parahippocampal gyrus and medial temporal area was increased. Also, our results showed the image representing the increase of blood supply in this area. So, our results suggest that BF-7 effectively help to use brain concerning with learning and memory.

• Radiation Oncology Journal
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• v.31 no.4
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• pp.199-205
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• 2013

Purpose: To assess the clinical efficacy and toxicity of whole pelvic intensity-modulated radiotherapy (WP-IMRT) for high-risk prostate cancer. Materials and Methods: Patients with high-risk prostate cancer treated between 2008 and 2013 were reviewed. The study included patients who had undergone WP-IMRT with image guidance using electronic portal imaging devices and/or cone-beam computed tomography. The endorectal balloon was used in 93% of patients. Patients received either 46 Gy to the whole pelvis plus a boost of up to 76 Gy to the prostate in 2 Gy daily fractions, or 44 Gy to the whole pelvis plus a boost of up to 72.6 Gy to the prostate in 2.2 Gy fractions. Results: The study cohort included 70 patients, of whom 55 (78%) had a Gleason score of 8 to 10 and 50 (71%) had a prostate-specific antigen level > 20 ng/mL. The androgen deprivation therapy was combined in 62 patients. The biochemical failure-free survival rate was 86.7% at 2 years. Acute any grade gastrointestinal (GI) and genitourinary (GU) toxicity rates were 47% and 73%, respectively. The actuarial rate of late grade 2 or worse toxicity at 2 years was 12.9% for GI, and 5.7% for GU with no late grade 4 toxicity. Conclusion: WP-IMRT was well tolerated with no severe acute or late toxicities, resulting in at least similar biochemical control to that of the historic control group with a small field. The long-term efficacy and toxicity will be assessed in the future, and a prospective randomized trial is needed to verify these findings.

• Imaging Science in Dentistry
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• v.40 no.1
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• pp.39-44
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• 2010

Purpose : We want to identify the appearance of the buccolingual root dilaceration teeth in the panoramic views and specify the characteristics of these teeth. Materials and Methods : One thousand-six patients were examined on the basis of both panoramic and CT image criteria. We diagnosed and excluded certain teeth from the samples; both prosthodontic or pathologic lesion appearing teeth and mesiodistally dilacerated ones. We meticulously discerned buccolingually dilacerated teeth in the CT images and total 48 samples were selected. The degree of severity in dilaceration was standardized by 2 types of criteria. The samples were differentiated into 3 groups and again categorized into six types showing from the panoramic views: irregular view on the root apex area, clear blunt on the root tip, stepping on root tip, double lamina dura or double tip, arrow-target shaped root, bull's eye, normal view. Results : The types of teeth selected from total 48 buccolingual root dilaceration samples were mandibular first and second molar, premolars, canines, and lateral incisors. The direction of dilaceration was an even percentage to each buccal and lingual side for most selected teeth, however, that of both canines and lateral incisors were directed in almost a buccal side. In the panoramic views, the root types of the buccolingually dilacerated teeth were irregular view on the root apex area, clear blunt on the root tip, stepping on root tip and normal types were almost always normal view. The more severity in dilareated degree, the more chances of observation in the panoramic views were clear blunt on the root tip and stepping on root tip. Conclusion : As observed in the shape of stepping on root tip or double lamina dura in the panoramic views, there can be much more probability to diagnose as a buccolingually dilacerated root.

• Tuberculosis and Respiratory Diseases
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• v.71 no.2
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• pp.126-133
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• 2011

Unilateral pulmonary artery hypoplasia (UPAH) is a rare disease in adults and is frequently accompanied by a congenital cardiac anomaly at a young age. The diagnosis is usually based on computed tomography (CT), angiography, and magnetic resonance imaging (MRI). However, no reports are available on retrograde flow in patients with UPAH. We describe a 68-year-old man with isolated UPAH and retrograde blood flow. He was admitted for dyspnea on exertion for the past 23 years. His diagnosis was delayed, as his symptoms and signs mimicked his underlying pulmonary diseases, such as emphysema and previous tuberculous pleurisy sequelae. A discrepancy was detected between the results of a ventilation-perfusion scan and the CT image. This was resolved by MRI, which showed retrograde blood flow from the right to the left pulmonary artery. Using MRI, we diagnosed this patient with isolated pulmonary artery hypoplasia and retrograde flow.

• Archives of Craniofacial Surgery
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• v.10 no.1
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• pp.49-54
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• 2009

Purpose: Inevitably, Maxillary structural defect follows maxillary cancer extirpation. Maxillary reconstruction is over every surgeon's head. Every physician tried to overcome limited donor site of craniofacial defect. We considered to suggest optimal method of inferior orbital wall defect in functional point as well as esthetic point. Methods: We performed wide excision of maxilla and vascularized partial thickness calvarial bone flap to reconstruct the defect from cancer extirpation in three cases. We select ipsilateral superficial temporal artery, vein and outer cortex of parietal bone flap as donor. And we applied bone flap as inferior orbital wall structure. The bony surface was wrapped with fascia to prevent direct contact between orbital contents and rough bony flap surface. Computed tomography image was checked during follolw up period. Results: We can observe these patients for over two years. In all three cases, We can get fair inferior orbital wall structure. Even though they got radiation therapy, there was no limitation of extraocular movements, no diplopia. no enophthalmos. Also there was minimal donor site morbidity. Conclusion: We suggest vascularized calvarial bone flap is practically excellent strategy for inferior orbital wall reconstruction.

• Journal of the Korean GEO-environmental Society
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• v.18 no.1
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• pp.31-35
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• 2017

The mechanical characteristics of frozen sand greatly depend on the frozen temperature and the fine contents according to the previous study by Chae et al. (2015). There are two hypotheses to explain this experimental results; one is the unfrozen water contents greatly affected by the fine contents and frozen temperature and the other is the sand particle spacing greatly affected by the pore-ice. To evaluate the latter hypothesis, the micro X-ray CT scan was performed. The micro X-ray CT scanning, one of the actively performed interdisciplinary research area, has a high resolution with micrometer unit allows to investigate internal structure of soils. In this study, X-ray CT technique was applied to investigate the effect of the frozen temperature and fine contents on the sand particle minimum and average spacing with the developed image processing techniques. Based on the spacing analysis, the frozen temperature and fine contents have little influence on the sand particle spacing in the frozen sand specimens.

• Imaging Science in Dentistry
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• v.39 no.1
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• pp.13-18
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• 2009

Purpose: This study was designed to determine a proper threshold value and opacity in three-dimensional CT volume rendering of oral and maxillofacial area. Materials and Methods: Three-dimensional CT data obtained from 50 persons who were done orthognatic surgery in department of oral and maxillofacial radiology of Seoul National University retrospectively. 12 volume rendering post-processing protocols of combination of threshold(100HU, 150HU, 221HU, 270HU) and opacity (58%, 80%, 90%) were applied. Five observers independently evaluated image quality using a five-point range scale. The results were analyzed by receiver operating characteristic curves, ANOVA and Kappa value. And three oromaxillofacial surgeons chose the all images that they thought proper clinically in the all of images. Results: Analysis using ROC curves revealed the area under each curve which indicated a diagnostic accuracy. The highest diagnostic accuracy appear with 100HU and 58% opacity. and the lowest diagnostic accuracy appear with 221HU and 58% opacity that are being used protocol in department of oral and maxillofacial radiology of Seoul National University. But, no statistically significant difference was noted between any of the protocols. And the number of proper images clinically that chosen by three oromaxillofacial surgeons is the largest in the cases of protocol 8 (221HU, opacity 80%) and protocol 11 (270HU, opacity 80%) in one after the other. Conclusion: Threshold and opacity in volume rendering can be controled easily and these can be causes of making an diagnostic accuracy. So we need to select proper values of these factors.

• Progress in Medical Physics
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• v.15 no.1
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• pp.23-29
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• 2004

The relationship between the dose calculated with a radiotherapy treatment planning system (RTPS) and CT number verses the relative electron density curve was investigated for various CT voltages and beam qualifies. We obtained the relationship between the CT numbers and electron densities of the tissue equivalent materials for various CT voltages and beam qualifies. At lower CT voltages, the higher density materials, like cortical bone, showed larger CT numbers and the soft tissues showed no variations. We peformed a phantom study in a RTPS, where a phantom consisted of lung and bone legions in water. We calculated the dose received behind the lung and bone regions for 6 MV photon beams, in which the regions below the lung, water and bone received higher doses in this listed order. The result was the same for 10 MV photon beams. For the clinical application, the doses were calculated for the lung and pelvis. No difference was observed when using different electron density conversion tables with various CT voltages from a same CT. A relative dose difference of 1.5% was obtained when the CT machine for the density conversion table was different from that for the CT image for planning.

• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.371-376
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• 2014

The process of flip-chip bump bonding, Au wire bonding and encapsulation were sucessfully developed and modularized. The CdTe sensor and ROIC were optimally jointed together at $150^{\circ}C$ and $270^{\circ}C$ respectively under24.5 N for 30s. To make SnAg bump on ROIC easy to be bonded, the higher bonding temperature was established than CdTe sensor's. In addition, the bonding pressure was lowered minimally because CdTe Sensor is easier to break than Si Sensor. CdTe multi-energy sensor module observed were no electrical failures in the joints using developed flip chip bump bonding and Au wire bonding process. As a result of measurement, shearing force was $2.45kgf/mm^2$ and, it is enough bonding force against threshold force, $2kgf/mm^2s$.