• Title/Summary/Keyword: 구내 방사선

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방사선 가공처리 시설 준공

  • Korean Federation of Science and Technology Societies
    • The Science & Technology
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    • v.8 no.11 s.78
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    • pp.6-7
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    • 1975
  • 원자력의 산업적 이용에 대한 기틀이 될 대단위 방사선 가공 처리 시범 시설이 칙공 1년만인 10월 15일 한국 원자력 연구소 구내에 준공되었다. 국제 연합 개발계획(UNDP) 기금 49만 불의 지원과 내자 3억4천만 원을 들여 완공한 이 시설에는 코발트-60을 조사원으로 하는 방사선 조사 장치와 30만 전자 볼트의 전자 가속 장치가 설치되었다. 이날 최형섭 과학기술처장관, UNDP 주한 대표 "찬드"씨, 윤용구 한국원자력 연구소장을 비롯 2백여병의 내외 귀빈이 참석한 가운데 이 시설은 시운전 기간을 걸쳐 76년 말 국제원자력기구(IAEA)로부터 운영권이 한국원자력연구소로 이관되어 방사선의 산업적 이용을 극대화하게 된다. 이 시범 시설의 운영 목적은 국내의 여러 산업 기관으로 하여금 방사선 가공 기술의 응용 범위와 생산성이 높다는 것을 실제로 깨닫게 하여 제품을 개량하므로서 수출 증대를 도모하는데 있다.

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The Effect of Recombinant Human Epidermal Growth Factor on Cisplatin and Radiotherapy Induced Oral Mucositis in Mice (마우스에서 Cisplatin과 방사선조사로 유발된 구내염에 대한 재조합 표피성장인자의 효과)

  • Na, Jae-Boem;Kim, Hye-Jung;Chai, Gyu-Young;Lee, Sang-Wook;Lee, Kang-Kyoo;Chang, Ki-Churl;Choi, Byung-Ock;Jang, Hong-Seok;Jeong, Bea-Keon;Kang, Ki-Mun
    • Radiation Oncology Journal
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    • v.25 no.4
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    • pp.242-248
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    • 2007
  • Purpose: To study the effect of recombinant human epidermal growth factor (rhEGF) on oral mucositis induced by cisplatin and radiotherapy in a mouse model. Materials and Methods: Twenty-four ICR mice were divided into three groups-the normal control group, the no rhEGF group (treatment with cisplatin and radiation) and the rhEGF group (treatment with cisplatin, radiation and rhEGF). A model of mucositis induced by cisplatin and radiotherapy was established by injecting mice with cisplatin (10 mg/kg) on day 1 and with radiation exposure (5 Gy/day) to the head and neck on days $1{\sim}5$. rhEGF was administered subcutaneously on days -1 to 0 (1 mg/kg/day) and on days 3 to 5 (1 mg/kg/day). Evaluation included body weight, oral intake, and histology. Results: For the comparison of the change of body weight between the rhEGF group and the no rhEGF group, a statistically significant difference was observed in the rhEGF group for the 5 days after day 3 of. the experiment. The rhEGF group and no rhEGF group had reduced food intake until day 5 of the experiment, and then the mice demonstrated increased food intake after day 13 of the of experiment. When the histological examination was conducted on day 7 after treatment with cisplatin and radiation, the rhEGF group showed a focal cellular reaction in the epidermal layer of the mucosa, while the no rhEGF group did not show inflammation of the oral mucosa. Conclusion: These findings suggest that rhEGF has a potential to reduce the oral mucositis burden in mice after treatment with cisplatin and radiation. The optimal dose, number and timing of the administration of rhEGF require further investigation.

Facemask Effects in Two Types of Intraoral Appliances : Bonded Expander vs. Hyrax (구내 장치 종류에 따른 facemask의 효과 비교 : bonded expander와 Hyrax)

  • Park, Chanyoung;Park, Kitae
    • Journal of the korean academy of Pediatric Dentistry
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    • v.42 no.1
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    • pp.45-52
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    • 2015
  • The purpose of this study was to compare and evaluate facemask effects when two types of intraoral appliances were used for maxillary protraction for patients with class III malocclusion. Eighteen patients with class III malocclusion were treated with a facemask for an average of 12 months. Two types of intraoral appliances were used: nine patients were treated with bonded expander (Group 1), and nine patients with Hyrax (Group 2). Cephalometric radiographs were taken before and after treatment. Cephalometric radiographs were traced, analyzed, and the results such as sagittal, vertical and soft-tissue changes were compared between two groups. The amount of anchorage loss was also measured to evaluate the difference between two groups. All patients showed significant sagittal skeletal changes after treatment, and there was no statistically significant difference between the two groups. When anchorage loss was evaluated, no differences were shown between the two. Facemask with Hyrax or bonded expander is similarly an effective method as a treatment in class III malocclusion patients.

A Study of Radiation Dose Evaluation and Optimization Methods for Intra Oral Dental X-ray in Pediatric Patient (소아 구내촬영 시 방사선량 평가 및 최적화 방안에 대한 연구)

  • Lee, Hyun-Yong;Cho, Yong-In
    • Journal of radiological science and technology
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    • v.44 no.3
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    • pp.195-203
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    • 2021
  • Although intra oral dental x-ray is a lower dose than other radiological examinations, pediatric patients are known to have a higher risk of radiation damage than adults. For this reason, pediatric dental x-ray requires management of dose evaluation and imaging conditions during the examination. In this study, the dose calculation program ALARA-Dental(child/adult) was used to evaluate the organ dose and effective dose exposed to each examination site during intra oral imaging of children during dental radiographic examination, and dose analysis according to the imaging conditions was performed. As a result, the highest organ dose distribution was shown at 0.044 ~ 0.097 mGy in all are as of the mucous membrane of oral cavity except for the maxillary incisors and canines. Also, in the case of the thyroid gland, the maxillary canine and maxillary premolar examination showed 0.027 and 0.020 mGy, respectively, and the dose distribution was 15.4% to 70.0% higher than that of the mandibular examination. As for the effective dose calculated during intra oral imaging, the maxillary anterior and canine examinations showed the highest effective doses of 0.005 and 0.004 mSv, respectively, and the maxillary area examination showed a higher dose distribution on average than the mandible.

Dose Change according to Diameter Change of the Cone for Dental X-ray Apparatus (치과구내용 X선발생기의 조사통 직경 변화에 따른 선량변화)

  • Ahn, Sung-Min;Oh, Jung-Hoan;Choi, Jung-Hyun;Shin, Gwi-Soon;Kim, Sung-Chul
    • The Journal of the Korea Contents Association
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    • v.10 no.3
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    • pp.266-270
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    • 2010
  • In case of the Dental X-ray apparatus, the diameter (or the field size) of the tip of the cone should be less than 7 cm according to the Diagnosis Radiation Equipment Safety Management. However, deviation from the field is not expected to be big as photography is made at close range from the skin. Also, as the size of film or digital detector used in intra-oral photography is $3\times4cm^2$, the size mentioned above can be considered to be much bigger. Furthermore, the patient dose by short-distance photography can not be ignored. Therefore, effect on the patient dose, resolution and image qualty was examined by reducing the cone diameter by 0.5 cm interval. The result showed that the patient dose was reduced and a partial improvement in picture contrast was observed. Therefore, it can be concluded from these results that further investigation may be worthwhile in terms of policy.

Evaluation of Radiation Doses of Dental Portable Equipment (치과용 이동형 방사선장치의 선량평가)

  • Park, Hoon-Hee;Kang, Byung-Sam
    • Journal of radiological science and technology
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    • v.41 no.5
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    • pp.445-450
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    • 2018
  • We aim to evaluate safety of radiation by measuring leakage dose and patient(phantom) incident dose of ZEN-PX II dental portable equipment developed by G company. Measurement for leakage dose of equipment is conducted on the top, at the bottom, on the left, on the right and at the back. Dose measurement incident on the subject with the area dosimeter when using the phantom and measurement the leakage dose of equipment when using the phantom are evaluated. Comparing the right with the highest leakage dose as a 0 cm, 25 cm, 50 cm, 75 cm and 100 cm dose measurement at the measurement height of 100 cm, 64.2 uR was reduced to 47.3 uR in the senser mode 0.32sec. Even in film mode it was measured at 414.4 uR and about 27% lower at 162.6 uR. As the result of this study, when the irradiation time is 2 sec the right side dose is 290.5 uR and sensor mode is 0.32 sec the right side dose is 64.2 uR.

Analysis of Condition Changing on Dose Variation using Intraoral Radiation Devices (구내 촬영용 방사선 장치의 촬영조건에 따른 선량변화 분석)

  • Kim, Young-Jae;Lee, Yong-Tak;Song, Hyeon-Cheol
    • Journal of the Korean Society of Radiology
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    • v.6 no.2
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    • pp.137-142
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    • 2012
  • This study is investigated dose change on intra-oral radiography when same conditions under the others unit and same unit under the different exposed conditions. Three different radiation devices were studied. Exposure to the upper anterior, premolar and molar on the variant time and dose measure was using semiconductor radiation dose meter. Obtained film density value was analyzed to the belong in the range of diagnosis. Results for dose of each region were less dissimilar between the maximum and minimum. Its value was different 10 times as many as 3 times. In addition, the range of film density was 2.10 ~ 2.95. These values were exceeded on the allow density of diagnostic value '0.25 ~ 2.0'. Even if the same device and the same condition, measured dose was considerable differance and film density was showed show the inappropriate density range. Those can be caused the patient's re-take and patient's diagnostic errors so patients has affected direct and indirect radiological harm. Therefore, dental radiography devices will be required periodical maintenance and also provided standard on the exposure and processing conditions.

Analysis of Chromosomal Aberration Induced by Low Dose of Radiation (저선량방사선에 의한 염색체이상 빈도)

  • Yi, Chun-Ja;Ha, Sung-Whan
    • Radiation Oncology Journal
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    • v.11 no.2
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    • pp.233-240
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    • 1993
  • Chromosomal aberration analysis, as a basis for biological radiation dosimetry, was performed for radiation dose ranges below 150 cGy. The yield, ratio of lymphocytes with dicentric and/or ring chromosomes, was 0, 0, 0.4, 0.5, 0.6, 0.8, 1.8, 5.5, 8.0, and $18.5\%$ for 0,5, 10, 15, 20, 25, 50, 75, 100 and 150 cGy, respectively. The Qdr, ratio of dicentric and ring chromosomes in total lymphocytes, was 0, 0, 0.004, 0.005, 0.006, 0.009, 0.018, 0.055, 0.084 and 0.207, respectively. The Qdr, ratio of dicentric and ring chromosomes in lymphocytes with aberration, was 1.0 for the radiation doses up to 75 cGy and 1.05 and 1.11 for 100 and 150 cGy, respectively. From the results, it seems possible to estimate radiation dose from Ydr when the exposure is 25 cGy or more. All the 5 radiation workers studied, with exposure much less than 1 mSv per month, had chromosomal aberrations. And acentric fragment pairs, in addition to dicentric and ring chromosomes, showed good dose response relationship and so may be useful for biological dosimetry for low dose radiation.

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A GEOMETRIC STANDARDIZATION OF PERIAPICAL INTRAORAL RADIOGRAPHY (구내 표준 방사선 사진촬영의 위치 표준화)

  • Choi Bong-In;Nah Kyung-Soo
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.21 no.2
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    • pp.415-423
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    • 1991
  • This study was performed to evaluate the geometric standardization of periapical intraoral radiography. Image distortion was measured by analysing serial radiography obtained from dry skull using 5 types of bite registration device. After 16 weeks, the angular distortion of Pattern resin was 0.26±0.14 degree(Horizontal angle 0.17±0.14, Vertical angle 0.16±0.11) which was the lowest among the 5 registration device, and that of putty type Exaflex was 0.49±0.35 degree(Horizontal angle 0.42±0.35, Vertical angle 0.17±0.13) which was the highest. The mean amount of distortion variance of Tooth shade acrylic at each experimental period was 0.06±0.08 which was the lowest among the 5 registration device, and that of XCP alone was 0.ll±0.13 which was the highest.

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