• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.3-23
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• 2024

Intervertebral disc herniation is frequently encountered in radiological practice. Sequestered disc herniation occurs when the disc material undergoes degeneration and completely loses continuity with the parent nucleus pulposus. Sequestered discs can reside within and outside the spinal canal, exerting a mass effect on adjacent structures, compressing nerve pathways, and eliciting a range of clinical symptoms. In particular, sequestered discs within the dura cannot be identified without durotomy. Therefore, precise preoperative localization is crucial for surgical planning. On MRI, the signal intensity of the sequestered disc may vary due to independent degeneration processes. Additionally, most sequestered disc fragments show varying degrees of peripheral enhancement depending on the degree of angiogenesis and granulation around the isolated tissue. In this article, we review various imaging findings and the location of the sequestered disc to provide patients with an accurate diagnosis and appropriate treatment direction.

• Economic and Environmental Geology
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• v.55 no.6
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• pp.737-760
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• 2022

For the geological disposal of high-level radioactive wastes (HLW), an understanding of deep subsurface environment is essential through geological, hydrogeological, geochemical, and geotechnical investigations. Although South Korea plans the geological disposal of HLW, only a few studies have been conducted for characterizing the geochemistry of deep subsurface environment. To guide the hydrogeochemical research for selecting suitable repository sites, this study overviewed the status and trends in hydrogeochemical characterization of deep groundwater for the deep geological disposal of HLW in developed countries. As a result of examining the selection process of geological disposal sites in 8 countries including USA, Canada, Finland, Sweden, France, Japan, Germany, and Switzerland, the following geochemical parameters were needed for the geochemical characterization of deep subsurface environment: major and minor elements and isotopes (e.g., ³⁴S and ¹⁸O of SO₄^2-, ¹³C and ¹⁴C of DIC, ²H and ¹⁸O of water) of both groundwater and pore water (in aquitard), fracture-filling minerals, organic materials, colloids, and oxidation-reduction indicators (e.g., Eh, Fe²⁺/Fe³⁺, H₂S/SO₄^2-, NH₄⁺/NO₃^-). A suitable repository was selected based on the integrated interpretation of these geochemical data from deep subsurface. In South Korea, hydrochemical types and evolutionary patterns of deep groundwater were identified using artificial neural networks (e.g., Self-Organizing Map), and the impact of shallow groundwater mixing was evaluated based on multivariate statistics (e.g., M3 modeling). The relationship between fracture-filling minerals and groundwater chemistry also has been investigated through a reaction-path modeling. However, these previous studies in South Korea had been conducted without some important geochemical data including isotopes, oxidationreduction indicators and DOC, mainly due to the lack of available data. Therefore, a detailed geochemical investigation is required over the country to collect these hydrochemical data to select a geological disposal site based on scientific evidence.

• Clinical and Experimental Pediatrics
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• v.48 no.10
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• pp.1121-1125
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• 2005

Purpose : Rotavirus is the main cause of infantile diarrheal disease worldwide, especially in patients 3-24 months of age. Infants younger than 3 months of age are relatively protected by transplacental antibody. So the purpose of this study is to evaluate the clinical features and severity of neonatal rotaviral gastroenteritis less than 1 month of age. Methods : A retrospective chart review was established of 62 neonates less than 1 month of age and with a diagnosis of rotaviral gastroenteritis who had been admitted to Pochon CHA University between June 2002 through July 2004. The rotavirus was examined by stool latex agglutination. Results : During 2 years, the total number of admitted patients for rotaviral gastroenteritis was 688 and among these, less than 1 month of age accounted for 9%(62). The occurrence was generally even distribution from January to July($7.14{\pm}1.0$) but since then decreased($2.4{\pm}1.8$). The most common chief complaint was mild fever(46%) when admitted which subsided within 1 hospital day in most patients. 4 patients had seizure and cyanosis with no typical symptoms of rotaviral gastroenteritis. During admission, all the patients had diarrhea. 17% of the patients had leukocytosis and positive C-reactive protein. In one patient, stool occult blood test was positive but there was no necrotizing gastroenteritis evidence. The mean period of hospital day was $5.8{\pm}2.5$ and breast-milk feeding was 62.9%. Conclusion : Neonatal rotaviral gastroenteritis is not a rare disease. Most patients have fever and diarrhea and improve through conservative therapy but a few patients may have severe complications so we must be more cautious about the hygiene for prevention.