• Journal of Korean Neurosurgical Society
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• v.51 no.1
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• pp.24-30
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• 2012

Objective : This study was conducted to assess the clinical significance of traumatic brain stem injury (TBSI) reflected on Glasgow Coma Score (GCS) and Glasgow Outcome Score (GOS) by various clinical variables. Methods : A total of 136 TBSI patients were selected out of 2695 head-injured patients. All initial computerized tomography and/or magnetic resonance imaging studies were retrospectively analyzed according to demographic- and injury variables which result in GCS and GOS. Results : In univariate analysis, mode of injury showed a significant effect on combined injury (p<0.001), as were the cases with skull fracture on radiologic finding (p<0.000). The GCS showed a various correlation with radiologic finding (p<0.000), mode of injury (p<0.002), but less favorably with impact site (p<0.052), age (p<0.054) and skull fracture (p<0.057), in order of statistical significances. However, only GOS showed a definite correlation to radiologic finding (p<0.000). In multivariate analysis, the individual variables to enhance an unfavorable effect on GCS were radiologic finding [odds ratio (OR) 7.327, 95% confidence interval (CI)], mode of injury (OR; 4.499, 95% CI) and age (OR; 3.141, 95% CI). Those which influence an unfavorable effect on GOS were radiologic finding (OR; 25.420, 95% CI) and age (OR; 2.674, 95% CI). Conclusion : In evaluation of TBSI on outcome, the variables such as radiological finding, mode of injury, and age were revealed as three important ones to have an unfavorable effect on early stage outcome expressed as GCS. However, mode of injury was shown not to have an unfavorable effect on late stage outcome as GOS. Among all unfavorable variables, radiological finding was confirmed as the only powerful prognostic variable both on GCS and GOS.

• Journal of Korean Neurosurgical Society
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• v.52 no.6
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• pp.513-516
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• 2012

Objective : It is rare that the medial loop in the V2 segment of the vertebral artery (VA) causes compression of the proximal cervical root of the spinal cord without leading to bony erosion and an enlarged foramen. We evaluated the clinical significance and incidence of the medial loop in the V2 segment of the VA. Methods : We reviewed the records from 1000 consecutive patients who had undergone magnetic resonance imaging evaluation of the cervical spine between January 2005 and January 2008. The inclusion criteria were that over a third of the axial aspect of the VA located in the intervertebral foramen was inside the line between the most ventral points of the bilateral lateral mass, and that the ipsilateral proximal root deviated dorsally because of the medial loop of the VA. We excluded cases of bone erosion, a widened foramen at the medial loop of the VA, any bony abnormalities, tumors displacing VA, or vertebral fractures. The medical records were reviewed retrospectively to search for factors of clinical significance. Results : In six patients (0.6%), the VA formed a medial loop that caused compression of the proximal cervical root. One of these patients had the cervical radiculopathy that developed after minor trauma but the others did not present with cervical radiculopathy related to the medial loop of the VA. Conclusion : The medial loop of the VA might have a direct effect on cervical radiculopathy. Therefore, this feature should be of critical consideration in preoperative planning and during surgery.

• Journal of Korean Neurosurgical Society
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• v.46 no.4
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• pp.365-369
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• 2009

Objective : Susceptibility-weighted image (SWI) is a sensitive magnetic resonance image (MRI) technique to detect cerebral microbleeds (MBLs). which would not be detected by conventional MRI. We performed SWI to detect MBLs and investigated its usefulness in the evaluation of mild traumatic brain injury (MTBI) patients. Methods : From December 2006 to June 2007, twenty-one MTBI patients without any parenchymal hemorrhage on conventional MRI were selected. Forty-two patients without trauma were selected for control group. According to the presence of MBLs, we divided the MTBI group into MBLs positive [SWI (+)] and negative [SWI (-)] group. Regional distribution of MBLs and clinical factors were compared between groups. Results : Fifty-one MBLs appeared in 16 patients of SWI (+) group and 16 MBLs in 10 patients of control group [control (+)], respectively. In SWI (+) group, MBLs were located more frequently in white matters than in deep nucleus different from the control (+) group (p<0.05). Nine patients (56.3%) of SW (+) group had various neurological deficits (disorientation in 4, visual field defect in 2, hearing difficulty in 2 and Parkinson syndrome in 1). Initial Glasgow Coma Scale (GCS)/mean Glasgow Outcome Scale (GOS) were $13.9{\pm}1.5/4.7{\pm}0.8$ and $15.0{\pm}0.0/5.0{\pm}0.0$ in SWI (+) and SWI (-) groups, respectively (p<0.05). Conclusion : Traumatic cerebral MBLs showed characteristic regional distribution, and seemed to have an importance on the initial neurological status and the prognosis. SWI is useful for detection of traumatic cerebral MBLs, and can provide etiologic evidences for some post-traumatic neurologic deficits which were unexplainable with conventional MRI.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.1040-1043
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• 2003

Henoch-Shonlein purpura(HSP) is a systemic small-vessel vasculitis that primarily affects the skin, gastrointestinal tract, joints, and kidneys. The nervous system may be involved, less commonly than other organs. When the central nervous system(CNS) was involved, headache, changes in mental status, seizures, and focal neurologic deficits have been reported. Hypertension, uremic encephalopathy, metabolic abnomalities, electrolyte abnormalities, or cerebral vasculitis were suggested as possible causes of the neurologic manifestation. Diagnosis of vasculitic involvement of CNS is difficult. Magnetic resonance imaging of the brain is the modality of choice for the evaluation of the CNS disease. Steroid or plasmapheresis are used in treatment of cerebral vasculitis. We experienced a case of 9-year-old boy who had presented with Henoch-Schonlein purpura nephritis complicating encephalopathy accompanied by hypertension and cerebral vasculitis. Brain MRI showed multiple small nodular-linear pattern enhancing lesions in whole cerebral hemispheres and focal increased T2 signal in the right basal ganglia. We used intravenous immunoglobulin in treatment of cerebral vasculitis. We report this case with a brief review of related literature.

• Composites Research
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• v.26 no.6
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• pp.386-391
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• 2013

In this paper, a carbon fiber/epoxy composite-aluminum hybrid wheel for passenger cars was suggested for better performance and a prototype was fabricated and tested. Adhesive bonding between aluminum part and a composite rim part was used, and the bonding length and thickness were determined by finite element analysis. For self alignment and the function of bonding jig the special structure with a groove and a protrusion was applied. To evaluate the performance of the hybrid wheel various FE analyses were carried out. Inner and outer molds were prepared for the composite rim part and the thermoformed composite part was bonded to the aluminum part. Vibration tests revealed that the hybrid wheel had 16% higher resonance frequency and 32% higher damping capacity with 10% weight reduction.

• Journal of Korean Foot and Ankle Society
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• v.14 no.1
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• pp.53-57
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• 2010

Purpose: This study was designed to evaluate the clinical and radiographical results of anatomical reconstruction by Chen method for chronic lateral ankle instability. Materials and Methods: Fifteen patients with chronic lateral ankle instability who had undergone anatomical reconstruction of anterior talofibular and calcaneofibular ligaments by Chen method were evaluated retrospectively. Average age of the patients was 31.3 years, and average follow-up period was 15.5 months. Preoperative and postoperative radiographs including varus stress view and magnetic resonance imaging (MRI) were analyzed. The clinical evaluation was performed according to the American Orthopaedic Foot and Ankle Society (AOFAS) scale. Results: Radiographically average talar tilt angle was $15.3^{\circ}$ preoperatively, and the difference with contralateral normal side was $10.1^{\circ}$. At last follow up, talar tile angle and the difference with contralateral side improved to $5.9^{\circ}$ and $1.3^{\circ}$ respectively. AOFAS scale was 66.6 preoperatively and 87.3 postoperatively. In MRI findings, four patients had associated intra-articular lesion such as articular cartilage defect, synovitis and osteoarthritis. The talar tilt angle improvement and AOFAS scale of patients without intra-articular lesion was better than those of four patients with intra-articular lesions. Surgical wound pain occurred in six patients and sural neuropathy in three patients. Conclusion: The anatomical reconstruction by Chen method was an easy and effective procedure for symptomatic chronic lateral ankle instability. Careful operative technique may prevent the surgical wound pain and sural neuropathy.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.174-174
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• 2009

The acromioclavicular-hook-plate is one of the surgical treatments for distal clavicle fracture and traumatic acromioclavicular (AC) joint dislocation. Although this procedure can obtain rigid and accurate anatomical reduction of the AC joint, secondary widening of the hook-hole in the acromion is often seen during postoperative follow-up. This complication is owing to the high-degree of mobility of the AC joint. Therefore, it is important to evaluate the effect on these complications due to the position of the hook-hole. The purpose of the present study is to investigate three-dimensionally the effect due to the position of the hook-hole during arm abduction motion. We studied in vivo and three-dimensional kinematics of the normal shoulder joint with use of a markerless bone-registration technique. Magnetic resonance images of 14 shoulders of 7 healthy volunteers were acquired in 7 positions between $0^{\circ}$ and $180^{\circ}$ of abduction. We created three-dimensional computer models of the bones and the acromioclavicular-hook-plate. Based on the three-dimensional kinematics data, we simulated the widening of the hook-hole each different positioning of the hook-hole. The widths of the hook-holes almost linearly increased. And these widths significantly increased, when we put the hook-hole on the acromion from AC joint to 20 mm and 25 mm posterior position.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.43-43
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• 2009

Glenohumeral ligaments play an important role in stabilizing the shoulder. However, it is impossible to know how they function in vivo during shoulder motion. To help elucidate this stabilizing role, we conducted in vivo three-dimensional kinematics of the normal shoulder joint using a markerless bone-registration technique. Magnetic resonance images of 14 shoulder joints of 7 healthy volunteers were acquired for 7 isometric abduction positions between $0^{\circ}$ and $180^{\circ}$. We then calculated three-dimensional shortest paths between the origin and insertion of each ligament based on anatomical study in each abduction position. At $0^{\circ}$ of abduction, the posterior band of the coracohumeral ligament displayed the maximum length. At $30^{\circ}$ of abduction, the superior glenohumeral ligament displayed the maximum length. At $60^{\circ}$ of abduction, the anterior band of the coracohumeral ligament and the middle glenohumeral ligament displayed the maximum length. At $120^{\circ}$ of abduction, the anterior band of the inferior glenohumeral ligament displayed the maximum length. We think that the maximum length of these results is an important influence on the function of the soft tissue stabilizer.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.3
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• pp.235-241
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• 2016

Underwater weapon system is required to structurally strong material, since as it is directly exposed to external shock. It should also be using the lightweight material in order to take advantage of buoyancy. Composite materials meet these requirements simultaneously. Particularly in the case of submarine, composite materials are widely used. It is important to have a high strength enough to be able to withstand external shock, but it is also important to attenuate it. In a method for the shock damping, viscoelastic damping materials are inserted between the high strength composite material as a sandwich structure. Shock attenuation can be evaluated in the loss factor. In ASTM(American Society of Testing Materials), evaluation method of the loss factor of cantilever specimens is specified. In this paper, mode tests of the cantilever are performed by the ASTM standard, in order to calculate the loss factor of the viscoelastic damping material by the specified expression. Further, for verifying of the calculated loss factor, mode test of compound beams is carried out. In addition, the characteristics of the material were analyzed the effect on the loss factor.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.17 no.3
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• pp.170-177
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• 2014

Purpose: Choledochal cyst is a cystic dilatation of common bile duct. Although the etiology is presently uncertain, anomalous pancreaticobiliary ductal union (APBDU) is thought to be a major etiology of choledochal cyst. In this study, we analyzed the clinical and anatomical characteristics and pathologies of patients diagnosed with choledochal cyst in a single institute for 25 years. Methods: A total of 113 patients, diagnosed with choledochal cyst and who received an operation in Severance Children's Hospital from January 1988 to May 2013, were included. Medical records were reviewed, including clinical and demographic data, surgical procedures. Abdominal ultrasonography, magnetic resonance cholangiopancreatography, and intraoperative cholangiography were used as diagnostic tools for evaluation and classification of choledochal cyst and the presence of anomalous pancreaticobiliary ductal union. Todani's classification, and relationship between APBDU and surgical pathology. Results: Among 113 patients, 77 patients (68.1%) presented symptoms such as hepatitis, pancreatitis and/or cholecystitis. Eighty three patients (73.5%) had APBDU, and 94 patients (83.2%) showed inflammatory pathologic changes. APBDU, pathologic inflammation, and serological abnormalities such as hepatitis or pancreatitis showed a statistically significant correlation to one another. Conclusion: APBDU is thought to be one of the etiologic factors of choledochal cyst. It is related to the inflammatory changes in bile duct that can lead to the cystic dilatation.