• Journal of Oral Medicine and Pain
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• 제48권3호
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• pp.81-86
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• 2023

Purpose: To evaluate the clinical and radiologic findings of the postoperative maxillary cysts (POMCs) and investigate the relationship between lesion size and clinical symptoms depending on the time elapsed after radical maxillary sinus surgery. Methods: A total of 29 patients who were diagnosed with POMCs at Chonnam National University Dental Hospital were selected. Clinical and radiologic findings were investigated. POMC cases were divided into two groups: those with <24 years between maxillary sinus surgery and POMC diagnosis and those with >24 years. The chi-square test was used to compare the differences between the two groups. Results: The average period from surgery to POMC detection was 24.32 years; however, the period could not be confirmed in four patients. The average patient age was 52.75 years, and 12 (41.3%) patients were in their 50s. POMC-related clinical symptoms were as follows: buccal pain and swelling, dull pain, toothache, abscess, sensory abnormality, and asymptomatic. Twenty (69.0%) cases showed unilocular radiolucency and 9 (31.0%) revealed multilocular radiolucency. Seven cases (35.0%) were misdiagnosed as odontogenic lesions, resulting in the delayed treatment of POMCs. No statistical significance was found between the two groups with respect to symptoms, expansion to the surrounding area, presence of secondary cysts, and mesiodistal length of cyst on cone-beam computed tomography (CBCT) images. However, the buccopalatal length of the cyst on CBCT images was significantly different between the two groups. Conclusions: The buccopalatal length of POMCs observed on CBCT images was related to the time elapsed since surgery. The lack of awareness of POMCs may lead to misdiagnosis as an odontogenic infection and delayed treatment. Therefore, dentists must recognize the clinical and radiologic features of POMCs to differentiate it from dental infections.

• 대한방사선기술학회지:방사선기술과학
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• 제36권3호
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• pp.193-200
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• 2013

2011년 3월 일본 동북해안의 지진과 해일, 그리고 연이은 후쿠시마 원전사고에 따른 국내의 방사선 피폭에 대하여 심각하게 우려되고 있다. 후쿠시마 원전에서 누출된 방사성 물질이 미량이나마 국내에도 검출되고 있어 방사성 물질에 대한 시민들의 불안감이 고조됨과 동시에, 국내 언론에서는 과학적인 접근 보다는 실시간으로 시민의 불안감에 편승하여 대중들을 방사선에 대한 공포로 몰아가는 상황이 자주 연출되고 있다. 이에 현상을 올바르게 직시하고 대안을 제시하기 위해 세계 각국의 보건, 의료기관 및 학술 단체에서는 의료방사선 안전문화 확산을 위해 다양한 정보를 제공하고, 의료방사선이 안전하다는 인식을 일반인에게 확산시키기 위한 캠페인을 실시하고 있다. 이에 국내에서도 지난 2011년 6월 초 식품의약품안전처의 제안으로 '의료용 방사선 관련 유관학회의 공동 심포지엄'의 개최를 위하여 마련된 유관학회 전문가 회의에서 공동 심포지엄의 개최 결정과 더불어, 의료용 방사선 안전을 위한 연합회 구성을 공식화하여 '의료방사선안전문화연합회(KARSM, the Korean Alliance for Radiation Safety and Culture in Medicine)'를 창립하게 되었다. 따라서 본 보고에서는 국외 의료방사선 안전문화 활동들에 대한 소개와 더불어 국내 의료방사선 안전문화 확산을 위한 의료방사선안전문화 연합회의 사업을 중점적으로 소개하고자 한다. 의료방사선 안전문화 확산과 관련한 여러 활동들을 통하여 일반 대중들에게 의료방사선의 막연한 공포감을 해소하고 바람직한 인식 형성에 기여하고자 한다.

• 대한디지털의료영상학회논문지
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• 제10권1호
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• pp.45-50
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• 2008

Recently, MR Cholangiography used mainly bu controlling of patient's breathing. There is breathing hold techniques to get images within shopt time and gating technique adjusted to respiration cycle for high resolution image. In this study, the aim of this experiment is to know on clinical usefulness compared with PACE and RTG thchniques. This study's period is from 2006 in November to 2007 in January. A total of 21 patients investigated at MAGNETOM Sonata 1.5T (SIEMENS Erlangen) with use of 12ch body coil. MR acquisition protocol used 3D turbo spin echo coronal sequence. Scan parameters applied to potimal setting in use as gating techniques, respectively. Analysis of consuming timing evaluated with rapidness. As analysis of quantity, the common bile duct, gall bladder measured in signal intensities, then these data were calculated by signal to noise ratio and contrast to noise ratio. Qualitative analysis, experienced 2radiologists and 3 RTs were evaluated into 3groups about artifact, accuracy of lesions, sharpness of the common bile duct or gall bladder. As a result of analysis, when compared to PACE, consuming time of the RTG took less than PACE, On both CNRs and SNRs, PACE technique was slightly high values than RTG(p<0.05). Qualitative analysis' results, discrimination of lesions in the common bile duct, gall bladder get a significance level in both RTG and PACE techniques but presence's artifact of breathing and pulsation highly demonstrate in PACE techniques. In conclusion, both PACE and RTG methods at MRCP provided prominently clinical information for the common bile duct, gall bladder. If machines have not limitation with performance, induction of breathing holding also will help getting diagnistic quality.

• 대한방사선기술학회지:방사선기술과학
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• 제24권1호
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• pp.23-26
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• 2001

The spatial distribution of the scattered dose for mobile X-ray radiography is measured. The scattered X-ray exposures at the radius of 50, 100 and 150 cm from the irradiation center are 880, 180 and $50\;{\mu}R$, respectively. This scattered X-rays can be reduced to 60% by inserting the portable shield made by 0.4 mm copper sheet sandwiched in two plywoods.

• 대한방사선기술학회지:방사선기술과학
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• 제21권2호
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• pp.43-46
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• 1998

When a patient was irradiated with prosthetic hip, the dose distribution was changed according to inhomogeneous materials. The density, effective atomic number, and the composition of material had influence on absorbed dose distribution. In this study, the influence of inhomogeneous material(Ti) was measured using a polyethylene phantom, which consisted of various diameter of titanium, with film dosimetry. As a result, the backward dose showed 29.5% increas by backscattering, the forward dose showed 28% decreas by absorption, and the side dose showed 7% increas by scattering, when 25 mm diameter Ti was used. In addition forward dose was in inverse proportion to the thickness of prosthetic material. When the prosthetic hip of patient is in an irradiated field, we must carefully study the absorbed dose distribution.

• 반도체디스플레이기술학회지
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• 제9권4호
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• pp.67-70
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• 2010

X-ray absorption rate and multiplication factor of X-ray detector were calculated with Garfield code. High Z (= atomic number) was important factor to increase the absorption rate but low Z is also important to increase the multiplication. Five different gas composition were examined under the condition of 1400 V bias and 400 um gap. Xe 100% gas showed the highest absorption rate and He 96% + isobutene 4% showed the highest multiplication.

• Nuclear Engineering and Technology
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• 제42권4호
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• pp.426-433
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• 2010

The characteristic X-rays emitted from materials after gamma ray exposure was simulated and measured. A CdTe semiconductor detector and a $^{57}Co$ radiation source were used for energy spectroscopy. The types of materials could be identified by comparing the measured energy spectrum with the theoretical X-ray transition energy of the material. The sample composition was represented by the $K_{\alpha1}$-line (Siegbahn notations), which has the highest intensity among the characteristic X-rays of each atom. The difference between the theoretic prediction and the experimental result of K-line measurement was < 0.61% even if the characteristic X-rays from several materials were measured simultaneously. 2D images of the mixed materials were acquired with very high selectivity.

• 대한방사선기술학회지:방사선기술과학
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• 제36권1호
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• pp.1-10
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• 2013

IEC 규격은 유럽, 일본 등 해외 여러 나라에서 자국의 규격으로서 이용되고 있으며, 우리나라에서는 현재 산업표준인 KS 형태와 더불어 강제성을 갖는 식품의약품안전청 고시로서도 발행되고 있다. 전자의료기기에 관한 IEC 규격인 IEC 60601 시리즈의 공통규격(IEC 60601-1:2005)이 3판으로 개정됨에 따라, 보조규격과 개별규격 또한 그에 맞추어 제 개정이 필요하다. IEC 규격의 변화 동향을 파악하는 것은 국내 의료기기 제조 수입업체 및 시험검사기관에서 매우 중요하다. 따라서 본 연구에서는, 진단용X선기기와 관련한 3개 규격 IEC 60601-2-44(CT의 기본안전과 필수성능에 관한 규격), IEC 60601-2-45(유방촬영용X선장치의 기본안전과 필수성능에 관한 규격), IEC 60601-2-54(진단용 X선장치의 기본안전과 필수성능에 관한 개별규격)에 대하여 IEC 60601-1의 3판에 맞추어 제 개정된 최신판의 동향 및 특징을 살펴보고자 하였다. 또한 현행 식품의약품안전청 고시가 IEC 60601-1의 2판이 적용된 개별규격을 참고로 하고 있어, 현행 식품의약품안전청 고시와 대비하여 그 특징을 살펴보았다. IEC 60601-1의 3판이 적용된 진단용X선장치 외 2개의 IEC 개별규격의 특징은 다음과 같다. 1) 기계적 위해요인, 특히 움직이는 부분에 대한 내용이 강화되었다. 2) 환자 선량을 표시 및 기록하도록 명시하고 있다. 3) 잠재적인 위험요소에 대해 체계적으로 관리가 가능한 위험관리 프로세스를 도입하고 있다. 4) 과거 Film-Screen System과 더불어 DR system(digital radiography system)에 대해서도 적용하고 있다. 현재 IEC 60601-1의 3판이 적용된 개별규격이 식품의약품안전청 고시로 개정될 예정이므로, 국내 시험 검사기관 및 의료기기 제조 수입업체 등에 유용한 자료가 되기를 기대한다.

• Imaging Science in Dentistry
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• 제30권4호
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• pp.249-254
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• 2000

Purpose: To clarify the clinical and radiologic parameters that can be used to differentiate odontogenic keratocyst and ameloblastoma Materials and Methods: The records of 46 patients of ameloblastoma and 48 patients of odontogenic keratocyst at the Yonsei University Dental Hospital during the period of 1979 to 1995 were retrospectively reviewed. As a possible means for differentiating between the odontogenic keratocyst and ameloblastoma, the clinical parameters and the radiologic parameters were evaluated. Results: In the clinical parameters, there was no significant difference in age, sex, and sign and symptoms (p>0.05). In the radiologic parameters, there was significant difference in site, shape of the lesion, and external root resorption of adjacent teeth (p<0.05). Conclusion: The site, shape of the lesion, and external root resorption of adjacent teeth can be the parameters to differentiate odontogenic keratocyst and ameloblastoma, but a definite differentiation of these two lesions needs a more specialized imaging modality.

• 한국수산과학회지
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• 제40권3호
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• pp.147-152
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• 2007

Spermiogenesis and mature spermatozoa of the Korean false minnow Pseudogobio esocinus (Cyprinidae) are described by means of scanning and transmission electron microscopy. Spermiogenesis is characterized by lateral development of the flagellum, absence of nuclear rotation, and eccentric nuclear fossa formation. The spermatozoa have a spherical head containing a nucleus with highly condensed chromatin and no acrosome. The nuclear fossa contains the proximal centriole and anterior part of the distal centriole. The midpiece is type A II and contains semi-fused mitochondria around the axoneme. However, the symmetrical distribution of 4 or more the mitochondria does not follow a general pattern of the cyprinid spermatozoa. Cytoplasmic vesicles in the midpiece are common in Cypriniformes and some of Siluriformes and Characiformes spermatozoa.