• 대한방사선기술학회지:방사선기술과학
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• 제46권5호
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• pp.409-415
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• 2023

Although pediatric X-ray examinations are continuously increasing, there are not many studies on the radiation exposure to children and X-ray examination assistants according to X-ray Exposure conditions. Accordingly, we measured the radiation exposure dose of pediatric and X-ray examination assistants according to the standard guidelines and clinical average X-ray Exposure conditions when X-ray examination 10-year-old children. The effective dose and organ dose to pediatric were measured using an Dose area production meter and Monte Carlo-based PCXMC program, and the exposure dose of X-ray examination assistants was measured using an ion-chamber. When performing abdominal supine AP projection, the effective dose to children was up to 2.38 times higher under clinical average X-ray Exposure conditions than the standard guidelines. In addition, during abdominal supine AP projection, the radiation exposure dose to the X-ray examination assistants was highest on the hands at 0.0148 ~ 0.0709 mSv, and exposure dose could be reduced by up to 35% when wearing protective gloves. In conclusion, because the X-ray Exposure conditions used in clinical are unnecessarily high, unnecessary medical radiation exposure could be reduced if appropriate X-ray Exposure conditions and the radiation field area were minimized and the assistant wore shielding gloves.

• Clinical and Experimental Pediatrics
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• 제53권3호
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• pp.286-293
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• 2010

Peak bone mass is established predominately during childhood and adolescence. It is an important determinant of future resistance to osteoporosis and fractures to gain bone mass during growth. The issue of low bone density in children and adolescents has recently attracted much attention and the use of pediatric dual-energy X-ray absorptiometry (DXA) is increasing. The process of interpretation of pediatric DXA results is different from that of adults because normal bone mineral density (BMD) of children varies by age, body size, pubertal stage, skeletal maturation, sex, and ethnicity. Thus, an appropriate normal BMD Z-score reference value with Z-score should be used to detect and manage low BMD. Z-scores below -2.0 are generally considered a low BMD to pediatrician even though diagnoses of osteoporosis in children and adolescents are usually only made in the presence of at least one fragility fracture. This article will review the basic knowledge and practical guidelines on pediatric DXA based on the International Society for Clinical Densitometry (ISCD) Pediatric Official Positions. Also discussed are the characteristics of normal Korean children and adolescents with respect to BMD development. The objective of this review is to help pediatricians to understand when DXA will be useful and how to interpret pediatric DXA reports in the clinical practice for management of children with the potential to develop osteoporosis in adulthood.

• 대한방사선기술학회지:방사선기술과학
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• 제46권6호
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• pp.543-551
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• 2023

In this study, the aim was to assess the shielding performance of different 3D printing materials, specifically those produced using FDM, SLA, and CJP methods, with a focus on their application as shielding devices in clinical settings. Additionally, the weight of lead shielding materials can evoke reluctance in pediatric patients undergoing X-ray imaging. A total of 12 materials were printed using their respective 3D printers. These materials were then subjected to X-ray testing using diagnostic X-ray equipment and an exposure meter. The goal was to evaluate their shielding capabilities in comparison to 1 mm lead. The results of this evaluation revealed that VisiJet PXL-Pastel, produced using the CJP method, exhibited the highest shielding performance. Therefore, VisiJet PXL-Pastel by CJP method was selected for the creation of a shielding device designed for pediatric reproductive organs. Subsequent tests demonstrated that both the newly created shielding device and conventional lead shielding equipment achieved the same maximum shielding rate at 50 kVp. Specifically, the shielding rate for the 3D printed device was measured at 84.53%, while the conventional lead shielding equipment, categorized as Apron1 (85.74%), Apron2 (99.98%), and Apron3 (99.04%), demonstrated similar performance. In conclusion, the CJP-produced VisiJet PXL-Pastel material showcased excellent radiation shielding capabilities, allowing for anatomical observations of the target organs and their surrounding structures in X-ray images. Furthermore, its lower weight in comparison to traditional lead shielding materials makes it a clinically practical and useful choice, particularly for pediatric applications.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제14권2호
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• pp.130-136
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• 2011

Plain X-ray radiographs are the first line of investigation taken in the diagnosis of abdominal pathology and are considered an important diagnostic tool to provide guidelines for further imaging studies and comprehensive therapeutic management. Although most abdominal pathology demonstrates non-specific radiologic findings, the plain abdominal radiography is very useful in specific diseases, including certain gastrointestinal anomalies. This review provides image findings of normal plain abdominal radiography and some common abdominal pathology in infants and children.

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

• 대한방사선기술학회지:방사선기술과학
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• 제44권3호
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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.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2022년도 하계학술대회
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• pp.1181-1183
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• 2022

신생아 호흡곤란증후군(RDS, Respiratory Distress Syndrome)은 미숙아 사망의 주된 원인 중 하나이며, 이 질병은 빠른 진단과 치료가 필요하다. 소아의 x-ray 영상을 시각적으로 분석하여 RDS 의 판별을 하고 있으나, 이는 전문의의 주관적인 판단에 의지하기 때문에 상당한 시간적 비용과 인력이 소모된다. 이에 따라, 본 논문에서는 전문의의 진단을 보조하기 위해 심층 신경망을 활용한 소아 RDS/nonRDS 판별 방법을 제안한다. 소아 전신 X-ray 영상에 폐 영역 분할을 적용한 데이터 세트와 증강방법으로 추가한 데이터 세트를 구축하며, RDS 판별 성능을 높이기 위해 ImageNet 으로 사전학습된 DenseNet 판별 모델에 대해 구축된 데이터 세트로 추가 미세조정 학습을 수행한다. 추론 시 입력 X-ray 영상에 대해 MSRF-Net 으로 분할된 폐 영역을 얻고 이를 DenseNet 판별 모델에 적용하여 RDS 를 진단한다. 실험결과, 데이터 증강과 폐 영역을 분할을 적용한 판별 방법이 소아전신 X-ray 데이터 세트만을 사용하는 것과 비교하여 3.9%의 성능향상을 보였다.

• 한국콘텐츠학회논문지
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• 제13권3호
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• pp.198-203
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• 2013

본 연구에서는 손, 머리, 복부 등에 대한 X선 촬영 시행 시 조사야 크기를 최적화할 경우와 최대화할 경우 검사목적부위로부터 30cm 거리에서의 X선 산란선량이 각각 어느 정도인지를 알아보았다. 그 결과 손, 머리, 복부 등에 대한 X선 산란선량은 첫째, 소인촬영의 경우 조사야 크기를 최적화하였을 때 각각 $0.08{\mu}Sv$, $4.39{\mu}Sv$, $5.56{\mu}Sv$로 나타났고, 조사야 크기를 최대화하였을 때 각각 $0.58{\mu}Sv$, $33.47{\mu}Sv$, $35.93{\mu}Sv$로 나타났으며, 둘째, 성인촬영의 경우 조사야 크기를 최적화하였을 때 각각 $0.40{\mu}Sv$, $14.51{\mu}Sv$, $18.86{\mu}Sv$로 나타났고, 조사야 크기를 최대화하였을 때 각각 $2.78{\mu}Sv$, $107.40{\mu}Sv$, $117.52{\mu}Sv$로 나타났다(P<0.001). 결론적으로, X선 촬영 시 조사야 크기를 필요한 만큼만으로 최대한 줄여주어 최적화시켰을 때에 최대화 시켰을 때보다 피사체 주변의 X선 산란선 발생량은 약 6~7배 정도 감소하였다.

• Korean Journal of Radiology
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• 제23권9호
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• pp.854-865
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• 2022

Photon-counting detector (PCD) CT is a new CT technology utilizing a direct conversion X-ray detector, where incident X-ray photon energies are directly recorded as electronical signals. The design of the photon-counting detector itself facilitates improvements in spatial resolution (via smaller detector pixel design) and iodine signal (via count weighting) while still permitting multi-energy imaging. PCD-CT can eliminate electronic noise and reduce artifacts due to the use of energy thresholds. Improved dose efficiency is important for low dose CT and pediatric imaging. The ultra-high spatial resolution of PCD-CT design permits lower dose scanning for all body regions and is particularly helpful in identifying important imaging findings in thoracic and musculoskeletal CT. Improved iodine signal may be helpful for low contrast tasks in abdominal imaging. Virtual monoenergetic images and material classification will assist with numerous diagnostic tasks in abdominal, musculoskeletal, and cardiovascular imaging. Dual-source PCD-CT permits multi-energy CT images of the heart and coronary arteries at high temporal resolution. In this special review article, we review the clinical benefits of this technology across a wide variety of radiological subspecialties.

• Childhood Kidney Diseases
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• 제3권2호
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• pp.187-195
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• 1999

목적 : 방광요관역류는 방광에서 요관과 신장으로 소변이 역류하는 현상으로 요로감염증의 약 1/3에서 발견되며 정도는 1도에서 5도까지 나눌수 있다. 소아의 방광요관역류의 진단에 있어 사용되는 RI VCUG(Radioisotope voiding cystourethrography(이하 VCUG)) 와 X-ray VCUG의 결과를 비교하여 방광요관역류의 진단에 어느 방법이 더 유용한지 평가하고자 본 연구를 시행하였다. 방법 : 1991년 1월부터 1998년 7월까지 7년 6개월동안 순천향병원 소아과 외래를 방문한 환아중 잦은 요로감염증이나 초음파 검사상 이상소견을 보인 9개월에서 17세까지 평균 5년 6개월의 남아 19명, 여아 21명을 대상으로 대상환아들에게 X-ray VCUG나 RI VCUG 또는 두가지 방법을 동시에 시행하였으며 요검사와 소변 배양검사를 1개월마다, 신장 초음파 검사를 3개월마다, RI VCUG를 6개월마다 추적검사를 시행하여 방광요관역류의 소실여부를 관찰하며 예후를 평가하였다. 결과 : 대상환아중 24명이 RI VCUG를 시행하여 17명이 방광요관역류소견을 보여 70.1%의 양성률을 보였고 22명이 X-ray VCUG를 시행하여 9명이 방광요관역류소견을 보여 40.1%의 양성률을 보였으며 19명이 두가지 검사를 모두 시행하여 15명이 RI VCUG상 양성소견을 보였고 이중 7명이 X-ray VCUG상 양성소견을 보였고 RI VCUG상 음성소견을 보인 4명은 X-ray VCUG 상에서도 음성소견을 보였다. 방광요관역류환아의 예후는 중복신장을 동반한 1례에서는 수술로 교정되었으며 다낭포신을 동반한 1례에서는 역류가 지속되었고 그외 단순한 역류에서는 자연소실과 반혼의 형성이 각각 8명이었으며 역류가 지속된 경우가 5명, 수술로 교정된 경우는 2명, 신기능이 감소된 경우가1명, 추적관찰이 되지않은 경우가 1명이었다. DMSA(2,3-dimercaptosuccinic acid 이하 DMSA) sacn상 방광요관역류환아 9명중 8명이 반흔을 형성하였고 역류가 없던 8명에서는 반흔을 형성하지 않았다. 요배양검사상 방광요관역류환아가 19명중 17명으로 역류가 없던 환아 21명중 15명이 양성소견을 보인것보다 양성률이 높았으며 원인균으로는 대장균이 가장많았고 방광요관역류환아에서 요로감염이 없던 기간은 14개월로 방광요관역류가 없는 환아에서의 26개월보다 짧았다. 결론 : 소아의 방광요관 역류의 진단에 있어 RI VCUG가 X-ray VCUG보다 양성률이 높음을 확인할수 있었다. 그러므로 초기진단시 방광요관 역류가 의심되나 X-ray VCUG로 발견되지 않은 경우에는 RI VCUG를 꼭 시행하는 것이 방광요관역류의 정확한 진단을 하는데 도움이 된다.