• Journal of the Korean Society of Radiology
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• v.15 no.1
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• pp.71-78
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• 2021

When continuous X-ray are used when acquiring and X-ray image, even the same material may not be accurately represented in the image according to the thickness due to various X-ray energies. To solve this problem, the X-ray energy spectrum was changed to improve the image quality. Using SPEKTR v3.0, an X-ray energy spectrum with an additional filter added and a general X-ray energy spectrum using only a unique filter were obtained. Simulation was performed using the obtained X-ray energy spectrum as a radiation source for Geant4 Application for Tomographic Emission (GATE). Using GATE data, an X-ray image with an additional filter and an image reconstructed from and X-ray image without an additional filter were compared and analyzed through a mono energy image of 74 keV. In the case of using the X-ray energy spectrum without using an additional filter, the amount of X-rays transmitted according to the thickness of the same material is different from the amount that decreases according to the thickness of the material. Similar results were obtained as the amount decreased with the material thickness. In other words, a similar result was obtained when the reduced dose was used with a mono energy. When an X-ray image is obtained by changing an X-ray energy spectrum using an additional filter, a more accurate result of transmission of X-rays may be obtained. In radiological examination, it was confirmed that the appropriate use of the additional filter has a great effect on improving the image quality.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.3
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• pp.181-190
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• 1998

A computerized tomography system was developed using the X-ray source that has diameter of 5 micrometer. The system is used for the nondestructive testing of specimens with diameter below 20 mm. The convolution back projection algorithm was adopted for the reconstruction of cross sectional image, and the shape of the X-ray beam was let parallel beam or fan beam to compare each resultant image. Our CT system was constructed to operate based on the personal computer. The sectional images of the fabricated specimens were reconstructed and analyzed. The reconstructed images well coincided with real images taken with optical microscope and gave us enough reports on the defects in the ceramic specimen. The resolution of the system regarded as about $20{\sim}30$ micrometers.

• Journal of the Korean Society of Radiology
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• v.13 no.6
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• pp.889-894
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• 2019

Upper gastrointestinal series is an examination that uses X-rays. It is important to defend against exposure to radiation during upper gastrointestinal examination because the organs, such as thyroid gland, lens, breasts, and gonads, with relatively high biological sensitivity to radiation are distributed on the examination area. We have made a whole body phantom that can change the depth of organs. radiation dose of eye, thyroid gland, breast and gonads were measured by the same procedure as the actual upper gastrointestinal examination. When performed only fluoroscopy the mean dose reduction of lens, thyroid gland, breast and gonads was 62.2%. The mean dose reduction of lens, thyroid gland, breast and gonads was 59.0% when both fluoroscopy and spot shoot were performed. Therefore, when performed upper gastrointestinal examination it was confirmed that shielding of the lens, thyroid gland, breast and gonads was effective in decreasing the exposure dose. The manufactured human phantom can be used in measuring radiation dose for deep organ because it can adjust the height corresponding to the organs located in the human body.

• Biomedical Science Letters
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• v.5 no.2
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• pp.191-200
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• 1999

In recent years continuously increasing number of tuberculosis (TB) cases due to the emergence of strains with multidrug resistance and AIDS is a significant global health problem. Therefore, more rapid and reliable diagnosis of TB may be one of the most urgent needs in efforts to eradicate the disease. The present study was designed to compare and assess the diagnostic values and efficiencies between the conventional methods (X-ray, AFB stain and culture) and PCR for pulmonary TB on 171 cases. Chest X-ray finding and clinical features revealed that 39 (22.8%) of 171 sputum specimens were pulmonary TB cases. The statistical data were taken on the basis of the definitive diagnosis: In X-ray, overall sensitivity, specificity, efficiency and false positive and false negative incidence was respectively 69.2%, 87.1％, 83.0%, 12.9%, and 30.8％； 79.5%, 95.5%, 91.8%,4.6％ and 20.5％ in AFB-stain; 56.4%, 99.2%,89.5%, 0.8% and 43.6% in culture; 82.1%, 96.2%, 93.0%, 3.8% and 17.9% in PCR. PCR got a highest sensitivity and efficiency as well as a lowest false negative incidence. Culture had a highest specificity with a lowest false positive incidence. These results imply that PCR assay is fast, sensitive and efficient method for diagnosis of pulmonary TB. However, combined use of the conventional methods with thorough quality control may offer more opportunities for detecting Mycobacterium tuberculosis and diagnosting TB although they have some limits.

• Pediatric Infection and Vaccine
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• v.24 no.3
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• pp.178-182
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• 2017

Paragonimiasis was one of the most common causes of cavitary lung lesions until the 1960s, but now it has become a very rare disease in Korea. A 16-year-old boy presented with hemoptysis and several days of cough. His plain chest radiograph showed nodular opacity with a cavity in the left upper lung region. Although his symptoms disappeared after taking antituberculous drugs, his plain chest radiograph and computed tomography images after completion of therapy showed a new nodule with a cavity in the left lung field. Through video-assisted thoracoscopic wedge resection, Paragonimus eggs were found in the lung tissues.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1987.05a
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• pp.18.2-18
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• 1987

Plastic bronchitis는 길고, 분지된 기관지원주(bronchial cast)의 형성과 기관지원주의 현미경 검사상, 염증세포를 포함하고 있는 농후한 점액의 층상 구조를 특징으로 하는 질환으로, 과거에는 fibrinous bronchitis, pseudomembranous bronchitis 그리고 Hoffman's bronchitis로 불려졌으며, 소아와 성인에서 발생하는 드문 질환으로 알려져 있다. 본 교실에서는 갑작스러운 발열, 기침 및 호흡 곤란을 동반하고, 흉부 단순 X-선 검사상 좌측 흉부에 무기폐 소견을 보인 19개월 남아에서, 기관지경 검사를 시행하여 제거한 조직의 육안 및 광학현미경 검사상 plastic bronchitis를 의심할 수 있는 1례를 경험하였기에 보고하는 바이다.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.4
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• pp.195-201
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• 2020

This study studied scoliosis, one of the most common modern diseases caused by lifestyle patterns of office workers sitting in front of computers all day and modern people who use smart phones frequently. Scoliosis is a typical complication that takes more than 80% of the nation's total population at least once. X-ray are used to test for these complications. X-ray, a non-destructive testing method that allows scoliosis to be easily performed and filmed in various areas such as the chest, abdomen and bone without contrast agents or other instruments. We uses NI DAQ to miniaturize digital X-ray imaging devices and image intensifier in self-shielding housing with Vision Assistant for drawing lines to the top and the bottom of the spine to acquire angles, i.e. curvature in real-time. In this way, the research was conducted to see scoliosis patients and their condition easily and to help rapid treatment for solving the problem of posture correction in modern people.

• Proceedings of the KWS Conference
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• 2000.10a
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• pp.251-253
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• 2000

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2619-2621
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• 2004

감마선 또는 x-선 등 방사선을 이용한 구조물 진단은 산업전반에 걸쳐 널리 이용되고 있다. 기존의 x-선이나 Ir-192의 감마선 등을 이용한 비파괴검사는 용접부의 확인이나 구조물의 내부 결점 확인과 같이 국부적인 진단에는 유용하나 석유화학산업에서 반응물의 분리 또는 정제 등에 많이 사용되고 있는 증류탑의 내부진단 실험에는 적합하지 않다. 증류탑은 목적에 따라 직경이 $3{\sim}10m$, 높이 $10{\sim}100m$에 달하는 대형 장치로서 내부의 이상현상에 대한 정확한 진단은 공정 전체의 가동효율 최적화에 결정적인 영향을 끼친다. 밀봉 감마선원으로부터 방출된 방사선의 투과율 변화를 증류탑의 반대편에 설치한 방사선 검출기로 측정하여 수직밀도분포(vertical density profile)를 구하여 증류탑의 내부현상에 대한 정확한 정보를 얻을 수 있는데 이러한 작업을 자동으로 수행할 수 있도록 한 것이 자동 증류탑 검사장치이다. 증류탑 진단장치는 크게 방사선 계측 및 데이터 전송회로, 방사선원부와 방사선검출부의 구동장치 및 구동회로, 데이터 수집 및 제어장치 둥으로 구성되어 있으며, 증류탑 검사를 자동화하여 진단결과의 신뢰도와 재현성을 향상시켰다. 본 논문은 방사선원과 방사선 검출장치의 위치를 자동으로 제어하면서 방사선 계측결과를 전송시키는 장치의 개발에 관한 내용으로서 개발된 장치의 소개와 산업현장 적용의 예를 소개함으로써 기존의 비파괴검사기술로는 진단할 수 없는 대형 증류탑의 진단에 효과적인 방사선 응용 계측장치임을 보이고자 한다.

• Tuberculosis and Respiratory Diseases
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• v.39 no.1
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• pp.15-23
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• 1992

Background: The prognosis of lung cancer remains poor and early detection and curative surgery is still the most effective treatment for many. In the early detection of lung cancer, sputum cytology and simple chest x-ray are used, but both of these tests are far from being perfect. So we studied the characteristics of patients diagnosed as lung cancer without demonstrable mass lesion on simple chest x-ray to help in the early diagnosis of lung cancer. Methods: We conducted a retrospective study on 11 subjects who were diagnosed as lung cancer at Seoul National University Hospital between August 1986 and June 1989 and had no demonstrable mass lesion on simple chest x-rays. Results: Ten of 11 patients were male, 8 had a history of smoking, most frequent symptoms were sputum, cough, and hemoptysis, and 3 patients either had wheezing or stridor. In 3 of the cases, although there were no mass lesion, there were ill-defined infiltration, major fissure thickening, and fibrostreaky density mimiking tuberculosis where the tumor was eventually found and in one patient tumor was masked by a rib shadow. Also in one case, lateral chest film demonstrated a retrocardiac mass. Both bronchoscopy and computed tomogram were useful in the localization of the tumor. Seven of 11 had relatively early disease (less than StageII). Four of 11 are still alive without any evidence of recurrence between 2 and a half and 4 years after the operation. Conclusion: We conclude that in patients with respiratory symtoms in whom cancer cannot be ruled out, sputum cytology and lateral chest x-rays should be taken and that if necessary further studies like computed tomogram and bronchoscopy should be done to aid in the early diagnosis of lung cancer.