• Imaging Science in Dentistry
• /
• 제30권3호
• /
• pp.183-188
• /
• 2000

Purpose: This study was to evaluate the beam quality of intraoral X-ray equipments used at Yonsei University Dental Hospital (YUDH) using the half value layer (HVL) and the characteristic curve of intraoral standard X-ray film. Materials and Methods : The study was done using the intraoral X -ray equipments used at each clinical department at YUDH. Aluminum filter was used to determine the HVL. Intraoral standard film was used to get the characteristic curve of each intraoral X-ray equipment. Results: Most of the HVLs of intraoral X-ray equipments were higher than the least recommended thickness, but the REX 601 model used at the operative dentistry department and the X-707 model used at the pediatric dentistry department had HVLs lower than the recommended thickness. The slopes of the characteristic curves of films taken using the PANP AS 601 model and REX 601 model at operative dentistry department, the X-70S model of prosthodontic dentistry department, and the REX 601 model at the student clinic were relatively low. Conclusion: HVL and the characteristic curve of X-ray film can be used to evaluate the beam quality of intraoral X-ray equipment. In order to get the best X-ray films with the least radiation exposure to patients and best diagnostic information in clinical dentistry, X -ray equipment should be managed in the planned and organized fashion.

• 한국치위생학회지
• /
• 제17권6호
• /
• pp.1053-1065
• /
• 2017

Objectives: The purpose of this study is to evaluate radiation safety education, knowledge and practice of dental hygienists in using handheld portable intraoral X-ray equipment and to suggest the need for radiation safety education in using handheld portable intraoral X-ray equipment. Methods: We surveyed 223 dental hygienists from July, 2017 to August in the dental clinics of Daejeon, Seoul and Gyeonggi area. Results: Radiation safety educational experience was higher in a year's career (72.9%), than 3 years experience (32.5%) (p<0.05). 82.7% of dental clinic workers took university education for radiation safety education while 55.6% of dental hospital workers took company training (p<0.05). More than 70% of the subjects did not have experience of radiation safety education about using portable intraoral X-ray. Radiation safety knowledge was highest in a year's career (p<0.05). The cumulative dose, radiation sensitivity, and lead defense knowledge were high in all subjects, but knowledge related to scattering radiation and scattering radiation sources was low. Practice of portable intraoral X-ray safety was significantly lower than knowledge. Conclusions: Knowledge of portable intraoral radiography safety is available, but performance is poor. Even with the small amount of radiation exposure, the risk is perceivable. There is a need to actively utilize the provided radiation protection products. In order to do this, efforts should be made to improve knowledge and performance of radiation safety through not only college education but also postemployment training.

• 치위생과학회지
• /
• 제15권3호
• /
• pp.254-258
• /
• 2015

치과병의원에서 사용하고 있는 이동형 치과 X선 발생장치를 이용하여 두경부 마네킹에 X선을 조사할 때 주변의 공간선량을 측정하고, 동일한 방법으로 고정형 X선 발생장치에 적용하여 측정된 공간선량을 상호 비교하며, 더불어 기기 및 위치별 공간선량을 비교 분석한 결과는 다음과 같다. 이동형 X선 발생장치의 평균 공간선량은 $37.51{\mu}Sv$로 고정형 X선 발생장치의 $10.77{\mu}Sv$보다 매우 높았다(p<0.001). 이동형 X선 발생장치의 기기별 공간선량은 $17.77{\mu}Sv$부터 $68.90{\mu}Sv$까지 큰 차이를 나타냈다(p<0.05). 위치별로는 직전 위치가 $54.14{\mu}Sv$로 가장 높았고, 직우 위치가 $13.60{\mu}Sv$로 가장 낮았으며, 직좌와 직후 위치는 $42.12{\mu}Sv$, $40.18{\mu}Sv$로 유사하였다(p<0.01). 이상의 결과를 통해 이동용 치과 X선 발생장치는 이동 불가능한 환자만을 대상으로 제한적으로 시행하여야 하며, 반드시 환자와 술자 모두 납 방어복을 착용하여 방사선 피폭을 최소화해야 할 것이다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2008년도 하계학술대회 논문집
• /
• pp.580-582
• /
• 2008

The object of this paper is develope the PC based controlled high voltage power supply and studies 1.2kW(120kV, 10mA) pulse power X-ray generator possible to adapt fluoroscopy of Dental CT X-ray generator and industrial X-ray pulse power equipment. The developed pulse power X-ray generator consisted of mono-block tank include X-ray tube and high voltage X-ray power supply circuit and high voltage control unit with RS232C/422 communication port. The PC control program of pulse power X-ray generator uses LabVIEW, and the size of high voltage transformer and high voltage generator is minimized by high voltage high frequency inverter has 100kHz switching frequency. Also this paper shows result of X-ray tube voltage and tube current correspond to variable load.

• Imaging Science in Dentistry
• /
• 제48권3호
• /
• pp.167-176
• /
• 2018

Purpose: In the age of X-ray computed tomography (CT) and digital volume tomography (DVT), with their outstanding post-processing capabilities, indications for planar radiography for the study of the dentition of ancient Egyptian mummies may easily be overlooked. In this article, the advantages and limitations of different approaches and projections are discussed for planar oral and maxillofacial radiography using portable digital X-ray equipment during archaeological excavations. Furthermore, recommendations are provided regarding projections and sample positioning in this context. Materials and Methods: A total of 55 specimens, including 19 skeletonized mandibles, 14 skeletonized skulls, 18 separate mummified heads, and 4 partially preserved mummies were imaged using portable digital X-ray equipment in the course of archaeological excavations led by the University of Basel in the Valley of the Kings between 2009 and 2012. Images were evaluated by 2 authors with regard to the visibility of diagnostically relevant dental structures using a 4-point grading system(Likert scale). Results: Overall, the visibility of diagnostically relevant dental structures was rated highest by both authors on X-ray images acquired using a dental detector. The tube-shift technique in the lateral projections of mandibular dentition achieved the second-best rating, and lateral projections achieved the third-best rating. Conclusion: Conventional planar digital X-ray imaging, due to its ubiquity, remains an excellent method-and often the only practicable one-for examining the skulls and teeth of ancient Egyptian mummies under field conditions. Radiographic images of excellent diagnostic quality can be obtained, if an appropriate methodology regarding the selected projections and sample placement is followed.

• 치위생과학회지
• /
• 제23권4호
• /
• pp.343-350
• /
• 2023

Background: Digital panoramic dental X-ray equipment (PDX) is frequently used by patients and dental workers for diagnosis and examination in dental institutions; however, infection control has not been properly implemented. Therefore, in this study, we aimed to systematically review the potential risk of cross-infection in the dental environment by investigating the contamination level of general aerobic bacteria and Staphylococcus aureus, which are important in hospital infections, in PDX areas that people mainly contact. Methods: This survey was conducted from March to May 2023 and covered one general hospital, three dental hospitals, and nine dental clinics equipped with PDX. Bacteria samples were collected from the left-handle, right-handle, forehead support, and head side support as the patient's contact areas, as well as the X-ray exposure switch and left-click mouse button as the dental hygienist's contact areas of the PDX. The collected bacteria were spread on Petrifilm, and colonies formed after 48 hours of culture were counted. Results: General aerobic bacteria and S. aureus were detected in all areas investigated. Significant differences in bacterial counts between different regions of the PDX were observed in both groups (p<0.001). The detection rates of general aerobic bacteria (p<0.001) and S. aureus (p<0.001) were significantly higher in the contact areas of patients than those of dental hygienists. A positive correlation was observed between the forehead and the temple region in terms of general aerobic bacteria and S. aureus detection (r=1) (p<0.01). Conclusion: Taken together, the presence of many bacteria, including S. aureus, detected in PDX indicates that PDX has a potential cross-infection risk. Our results therefore highlight the need for the development of appropriate disinfection protocols for reusable medical devices such as PDX and periodic infection prevention training for hospital-related workers, including dental hygienists.

• 전자통신동향분석
• /
• 제34권5호
• /
• pp.1-13
• /
• 2019

In modern times, X-ray imaging has become a necessary tool for early diagnosis, quality control, nondestructive testing, and security screening. X-ray imaging equipment generally comprises an X-ray generator and an image sensor. Most commercially available X-ray generators employ filament-thermionic electron-based X-ray tubes, thus demonstrating typical analog behavior, such as slow response and large stray X-rays. Furthermore, digital X-ray sources, which have been studied extensively using field electron emitters manufactured from nanometer-scale materials, provide fast and accurately controlled ultra-shot X-rays. This could usher in a new era of X-ray imaging in medical diagnosis and nondestructive inspections. Specifically, digital X-ray sources, with reduced X-ray dose, can significantly improve the temporal and spatial resolution of fluoroscopy and computed tomography. Recently, digital X-ray tube technologies based on carbon nanotubes, developed by Electronics and Telecommunications Research Institute, have been transferred to several companies and commercialized for dental imaging for the first time.

• 대한방사선기술학회지:방사선기술과학
• /
• 제39권4호
• /
• pp.651-660
• /
• 2016

최근 인구고령화로 인하여 치과진료 주요대상인 노인층의 검사가 꾸준히 증가하고 있다. 따라서 치과 진단용 엑스선장치 시장도 꾸준히 성장하고 있으며, 동시에 치과용엑스선장치의 허가 심사건수도 증가하고 있다. 의료기기 기술문서는 의료기기의 허가 심사 시 필수로 요구되는 자료이며, 해당 의료기기의 전반적인 항목을 기술해야 하는 만큼 작성자의 업무 이해도 및 전문성이 필요하다. 그러나 국내 의료기기 제조 수입 업체 대부분이 영세하여 의료기기 인 허가 관련 전문 인력의 확보가 쉽지 않아, 이로 인한 기술문서의 부정확한 작성이 증가하고 있다. 이에 따른 심사자의 민원 처리 지연과, 제품의 신속한 시장 진입의 어려움이 발생되고 있다. 특히 치과용구강외엑스선장치, 치과용구강내엑스선장치, 암형전산화단층엑스선촬영장치, 포터블엑스선 촬영장치(이하 치과용엑스선장치)는 식품의약품안전처 기준 규격이 최근에 제정되거나 부재한 품목으로, 의료기기 제조 수입업체에서 시험항목 설정 시 많은 어려움을 겪고 있기에, 개선된 규격이 반영된 치과용엑스선 장치 가이드라인(안)을 개발하여 관련 업체 및 심사자에게 도움을 주고자 한다. 본 연구를 위하여 첫째, 기술문서에 대한 개선된 제도 운영 조사 및 의료기기의 제도 적용에 따른 문서 작성 방법을 검토하였으며, 둘째, 품목별 시장현황을 조사하고, 국내 외 규격을 분석하였으며, 셋째, 기 허가된 제품의 기술문서를 분석하여 품목별 올바른 작성방법과 국제조화된 시험항목, 기준 및 방법을 도출하였다. 마지막으로, 산 연 관 전문가 협의체 회의를 통하여, 공정하고 전문성이 강화된 기술문서 작성 가이드라인(안)을 도출하였다.

• 한국멀티미디어학회논문지
• /
• 제8권4호
• /
• pp.482-491
• /
• 2005

본 논문에서는 디지털 X선 유방 촬영 시스템에서 획득된 영상으로부터 웨이브릿 변환과 자동적인 임계치 설정기법을 이용하여 미세 석회화 영역을 추출하였다. 디지털 X선 영상 장비는 임상 진단 분야에서는 필수적인 진단 장비이며, 흉부 촬영, 골절상 및 치아 교정 등의 다양한 분야에 사용되고 있다. 특히 디지털 X선 유방 촬영술은 유방암 진단의 가장 좋은 방법으로 알려져 있으며 최근 국내에서 디지털 X선 기기를 개발하기 위한 많은 연구들이 진행되고 있다. 본 논문에서는 디지털 X선 유방 촬영 영상으로부터 초기 단계의 유방암 진단을 위해 필수적인 미세 석회화를 검출하는 알고리즘을 제안하여 이를 효과적으로 검출하였으며 진단 방사선학적 진단에 도움을 줄 수 있음을 보였다.

• 한국콘텐츠학회논문지
• /
• 제10권3호
• /
• pp.266-270
• /
• 2010

진단용방사선발생장치의 안전관리법에 의하면 치과 구내촬영용 X선발생기의 경우 조사통의 조사야 크기는 촬영면에서의 최대지름이 7 cm이하가 되게 기준 되어있다. 하지만 실제 두개부에 붙여서 촬영하는 근접촬영이기 때문에 X선 조사면적을 벗어날 염려가 없으며, 구내촬영에 사용되는 필름 또는 디지털 디텍터의 크기도 $3\times4cm^2$의 크기이기 때문에 훨씬 큰 편이며, 근거리 촬영에 따른 환자의 피부선량도 무시할 수 가 없다. 이에 조사통의 지름을 0.5 cm간격으로 줄이며, 환자선량, 해상력 및 화질의 영향을 알아본 결과 조사통 직경이 5 cm가 되어도 사용에 따른 큰 불편이 없으면서 환자선량 감소 및 사진의 대조도 증가 효과를 볼 수 있어 정책적으로 검토해볼 사항이라는 연구 결과를 얻었다