• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.3
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• pp.273-279
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• 2012

Purpose : This study was aimed to calculate effective dose from cone beam CT and compare effective dose from periapical and panoramic radiography for mesiodens. Materials and Methods : Upper anteiror periapical, panoramic radiography and cone-beam CT were taken for diagnosis of mesiodens. The effective dose were calculated by using an anthropomorphic phantom loaded with thermoluminescent dosimeters at the 23 sites related to sensitive organs. Results : The highest absorbed doses were received by the mandibular body, parotid gland and cheek from periapical, panoramic and cone-beam CT, respectively. The effective doses for periapical, panoramic radiography and cone-beam CT measured 2, 18 and 48 ${\mu}Sv$. Conclusion : Cone-beam CT, although providing additional diagnostic benefits, exposes patients to higher levels of radiation than conventional periapical and panoramic radiography.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.2
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• pp.195-201
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• 1992

The authors evaluated the distribution of the antral pathologic conditions and their radiographic features on the Waters' radiolgraphs of 151 children patients who had been radiographed at the department of Oral Radiology, Seoul National University Hospitals. The obtained results were as follows: 1. The most common pathologic condition was inflammatory change(58%). Percentage of cases showing cystic lesion and fibro-osseous lesion were 25% and 11% respectively. 2. In cases of inflammatory change, odontogenic origins were 12 cases(13%) and bilateral occurrences were 37 cases(39%). 3. The most common radiographic feature of the inflammatory conditions was various types of mucosal thickenkng(78%).Percentage of cases showing totally increased radiopacity was 18%. 4. Intrinsic cystic lesions were 26 cases(65%) and dentigerous cyst was the most common extrinsic cyst. 5. Most of the fibro-osseous lesions(15 from 17 cases) were fibrous dysplasia. 6. Maxillary sinus hypoplasia(5 cases) and Burkitt's lyphoma(4 cases) were also observed.

• Journal of Oral Medicine and Pain
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• v.26 no.3
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• pp.291-300
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• 2001

본 연구는 측두하악관절장애의 증상이 있는 악관절의 통상적인 방사선 단층촬영술에 대한 해석과 관절강 측정에 대한 조사자내, 조사자간 신뢰도를 조사하였다. 신뢰도 검사는 조사자들 간에 판독의 일관성이 있는지와 일정 시간이 지난 후 반복 측정 시 판독의 정확성이 있는지를 알아보기 위하여 시행하였다. 조사자내 상관계수는 과두 형태에 대해서는 각각 0.812와 0.619, 골변화 형태에 대해서는 모두1.00, 골변화에 대해서는 0.846과 0.991, 전방관절강에 대해서는 0.919와 0.966, 상방관절강에 대해서는 0.864와 0.955, 그리고 후방관절강에 대해서는 0.718과 0.672였다. 통상적인 방사선 단층촬영술이 신뢰도가 있음을 보여주는 이 연구의 결과로 보아, 측두하악 관절을 평가하는데 있어서 통상적인 방사선 단층촬영술은 높은 진단학적 정확성과 조사자간 일치성을 가진다고 할 수 있다.

• Journal of radiological science and technology
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• v.2 no.1
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• pp.3-9
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• 1979

이상 방사면역측정(放射免疫測定)의 기본원리(基本原理), 순수(純粹)한 항원(抗原), 표지항원(標識抗原), 항체생성(抗體生成), 표준곡선(表準曲線)의 작성(作成), 항원항체복합체(抗原抗體複合體)의 분리방법(分離方法)에 대(對)하여 설명(說明)하였다. 생물학적방법(生物學的方法),화학적방법(化學的方法), 기계적(機械的)인 측정방법(測定方法)에 의(依)해 생체내(生體內)의 미량(微量)으로 존재(存在)하고 있는 물질(物質)들을 정확(正確)하게 측정(測定)할 수 없다. 그러나 방사면역측정법(放射免疫測定法)에 의(依)해 쉽게 측정(測定)되어 기관(器管)의 기능검사(機能檢査)는 물론(勿論) 각(各) 기관(器管)과의 상관관계(相關關係)를 분석(分析)하여 질병(疾病)의 진단(診斷), 치료경과(治療經過)을 평가(評價)하는데 매우 중요(重要)한 정보(情報)를 제공(提供)해주고 있다. 이러한 점(點)을 고려(考慮)하여 이 방법(方法)을 잘 습득(習得)하고 진료(診療)의 수단(手段)으로 널리 이용(利用)되어 의료기술발전(醫療技術發展)에 토대(土臺)가 되기를 바란다.

• Journal of Radiation Protection and Research
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• v.24 no.2
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• pp.93-99
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• 1999

The alkaline single-cell gel electrophoresis (SCGE) assay, called the comet assay, has been applied to the detection of DNA damage from a number of chemical and biological factors in vivo and in vitro. The comet assay is a novel method to assess DNA single-strand breaks, alkali-labile sites in individual cells. The effect of peach kernel extracts on radiation-induced DNA damage in human blood lymphocytes was evaluated by the SCGE assay. The lymphocytes, with or without pretreatment of the extracts, were exposed to 0, 0.1, 0.3, 0.5, 1.0 and 2.0 Gy of $^{60}Co$ gamma ray. Significantly increased tail moment, which was a marker of DNA strand breaks in the comet assay, showed an excellent dose-response relationship. The treatment of the peach kernel extracts reduced the DNA damage by 30 % in irradiated groups as compared to that in non-treated control groups. The result indicates that the extracts shows radioprotective effect on lymphocyte DNA when assessed by the comet assay.

• Journal of Veterinary Clinics
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• v.29 no.3
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• pp.263-267
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• 2012

A 4-year-old female Labrador Retriever dog was evaluated for a mass located in the left maxilla. Skull radiographic and CT findings revealed a soft tissue mass with bone lysis in the region of the left maxilla. Mass resection and surgical curettage was performed, and the mass was histopathologically classified as an acanthomatous ameloblastoma with a fibrous dysplasia.

• Journal of radiological science and technology
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• v.33 no.3
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• pp.173-178
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• 2010

In projection radiography, two types of digital imaging systems are currently available, computed radiography (CR) and digital radiography (DR): a difference between them can be stated in terms of dose and image quality. In the Department of Radiology our hospital, a flat-panel DR equipment (Digital diagnost, Philips) and two CR systems (ADC Compact plus digitizer, AGFA) are employed. Eight standard radiographic examinations (Skull AP, Skull LAT, Chest PA, Chest LAT, Abdomen AP, L-spine AP, L-spine LAT, Pelvis AP) were considered: doses delivered to patients in terms of both entrance skin dose (ESD) were calculated and compared in order to study the dosimetric discrepancies between CR and DR. Assessment of image quality is undertaken by Consultant Radiologists to ensure that the quality criteria for diagnostic radiographic images of the European guidelines were met. Results showed that both ESD in DR are lower than that in CR; all images met the criteria in the European Guidelines for both modalities and were used for reporting by the radiologists. Since the operators are the same and the image quality is comparable in both modalities, this study shows that in the considered examinations, DR can perform better than CR from a dosimetric point of view.

• Journal of Radiation Protection and Research
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• v.25 no.4
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• pp.217-221
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• 2000

Radiotheraphy may be considered as one of the most effective treatments for digestive tumors. This procedure has major side effects, especially in fast growing tissues like intestinal mucosa. For this reason, the morphological changes in mouse jejunal villi after whole body ${\gamma}-irradiation$ were analysed. Four week old ICR male mice were irradiatied with 6.5Gy or 12Gy of whole body ${\gamma}-irradiation$ and were sacrificed 3 days later. Jejunum among intestine were taken for morphology. Samples were carried out dehydration process and sliced sample covered with paraffin was hold on the slide and then light microscopy was observed by Hematoxylin & Eosin staining. villi at both irradiated doses were showed that the length of villi were shortened and thickened and that lumen were expanded in comparison with non-irradiated group. Since willi have an important role in digestion and very sensitive to radiation from this test, it has a role of test parameter for finding radioprotectors as well as evaluating the biological effect by radiaton.

• Journal of Veterinary Clinics
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• v.25 no.2
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• pp.96-101
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• 2008

This study was performed to quantify the pleural effusion in radiography, ultrasonography and computed tomography(CT) and to evaluate and compare the usefulness of these methods. Normal saline of 10 ml/kg was infused into the pleural space until a final loading volume of 60 ml/kg body weight was reached in six Beagle dogs. The radiographic examination was performed for the detection and quantification of pleural effusion. On the ultrasonographic study, the maximum perpendicular distance was measured between the surface of the lung and the thoracic wall to evaluate pleural effusion. On the CT image, pleural effusion was evaluated as the perpendicular distance to the thoracic surface in the maximum pleural effusion volume on any transverse images with soft tissue window. Statistical analysis was performed using linear regression test. The volume of pleural effusion and measurements of radiography and ultrasonography had no statistical relationship. However, a significant correlation was identified between the volume of pleural effusion and the depth at right ($r^2=0.715$), left ($r^2=0.745$), and mean right and left depth ($r^2=0.844$) on the CT images. All of the thoracic radiographs, ultrasonography, and CT are useful in recognition of pleural effusion. In quantification of pleural effusion, the CT measurement method is superior to radiographic and ultrasonographic measurements.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.255-260
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• 2005

Stability of functional properties and chemical components of gamma-irradiated Astragali Radix (AR) were investigated to study the application of radiation technology for preservation and hygiene of medicinal herbs. Thus, ethanolic extracts and ethyl acetate fractions were prepared from gamma-irradiated and gamma-nonirradiated AR, respectively. Functional properties were estimated by comparing antioxidant activity (DPPH radical scavenging activity, lipid peroxidation inhibitory activity) and protective effect against oxidative DNA damage in human lymphocytes. Chemical components were compared by HPLC analysis, comparing with calycosin ($_{t}$ R= 15.111 min), which was isolated from ethyl acetate fraction as a standard material. Their antioxidant activities and protective effects against oxidative DNA damage showed no significant difference at the concentrations tested. HPLC analysis also showed almost same pattem. These results suggest that the functional properties and chemical components of AR are not affected largely by gamma irradiation, and radiation technology can be applied to preservation and hygiene of medicinal herbs.s.