이중 에너지 검출기를 이용한 영상 시스템

여화연(Yeo, Hwa-Yeon) 한국산학기술학회 2010 한국산학기술학회논문지 Vol.11 No.9

본 논문은 이중 에너지 DR(Digital Radiography) 방식 중, 단일 조사 X-선(single shot X-ray exposure) 장치 와 이중 모드 검출기 모듈 (Low Energy Detector & High Energy Detector)을 이용한 이중 X-선 이미징이 가능한 검 출기 모듈에 관한 연구이다. 상용 BIS(baggage inspection system)에서 사용되고 있는 X-선 발생장치의 스펙트럼과 이중 모드 검출기에 대한 특징 및 방사선적 특성을 분석하여 새롭게 제안 할 검출기 모듈의 최적 설계 방향을 기술하고 상용화된 용화된 LED 및 HED 검출기와 새롭게 제안 한 검출기 모듈에 대해 전기적, 광학적, 방사선적 특성 실험을 실시하여, 새롭게 제안 된 검출기 모듈이 BIS 용도로 사용 가능함을 증명하였다. 새롭게 제안 된 검출기 모듈이 적용된 BIS에 대해, 기본 특성 실험에 대한 X-선 영상을 획득하여 실험 및 분석을 실시하였다. Single exposure dual X-ray imaging can be used to separate soft and dense-material images for medical and industrial applications. This study keep focusing baggage inspection system(BIS) specifically. New detector modules for single exposure dual X-ray imaging are consisted of low energy detector (LED) and high energy detector (HED). First, the optimized thickness of copper filter coupled HED to separate low energy and high energy was simulated by the given X-ray energy (140 kVp, 1 mA) using Monte Carlo simulation codes, MCNPX. So as a result of simulation, the copper filter thickness is 0.7 mm. For the design of PIN photodiode, ATLAS device simulation tool was used. 16 channels PIN photodiode of 1.5 mm x 3.2 mm for Dual X-ray imaging detector was fabricated in the process of ETRI. And its dark current and quantum efficiency, terminal capacitance were measured. It was proven that the Lanex Fast B coupled HED were a sufficient candidate to replace the CsI(Tl) commerced in dual X-ray system, since these give a strong signal, overcoming system noise. Finally dual X-ray image was acquired through correction of the LED X-ray Image and the HED X-ray Image.

관상동맥 조영술 및 중재술시 요골동맥과 대퇴동맥의 사용에 관한 비교연구

문일봉 ( Il Bong Moon ),여화연 ( Hwa Yeon Yeo ),임환열 ( Hwan Yeal Lim ),동경래 ( Kyung Rae Dong ) 조선대학교 공학기술연구원 2015 공학기술논문지 Vol.8 No.4

Coronary angiography and interventional study mostly use the methods of radial artery and Femoral artery. The results of 116 patients (65.% male with an average age of 63.3±11.54)who had Coronary angiography and interventional study treatments from June 12th, 2014 to September 2nd, 2014 at the Chonnam National University Hospital were analyzed. For patients who had an angiography with interventional study treatment were divided into two groups (group 1: radial artery, group 2: femoral artery) and analyzed. For the group that used the radial artery the frequency of Coronary angiography interventional study was lower (19.5% vs. 55.9%, p<0.001), and the inner radius was smaller (5.20±0.429french vs. 6.18±0.999french, p<0.001), and the amount of contrast media used was smaller (66.8±43.30cc vs. 105.7±60.30cc, p=0.001). However, there was no difference for gender, age, BMI, type of artery, radiation exposure duration and amount. In the sub-analysis, for the group that only had the Coronary angiography without the interventional study treatment and where the radial artery, the radiation exposure duration was longer than that of the group that used the femoral artery (392.30±205.263sec vs. 282.13±82.984sec, p=0.002). However, there were no differences for the other parameters. Also, for the group that had both the Coronary angiography and interventional study treatment showed no difference for all parameters. In conclusion, it can be stated that Coronary angiography that uses the radial artery and interventional study treatment, which is widely know to be comfortable for the patient and to also lower the risk for hemorrhaging, is a better and safer treatment method.

유방촬영팬텀을 이용한 Film-Screen 방식과 DR 방식의 영상 비교 분석

강병삼 ( Byung Sam Kang ),여화연 ( Hwa Yeon Yeo ),동경래 ( Kyung Rae Dong ) 조선대학교 공학기술연구원 2013 공학기술논문지 Vol.6 No.1

Recently, interests and utilization on Computed Radiography (CR) and Digital Radiography (DR) have tended to increase owing to an introduction of Picture Archiving and Communication System (PACS) and an accuracy control of special medical equipment for breast imaging. The present paper compared the breast image of Film-Screen methods and DR methods using the breast photographing system for accuracy of breast cancer diagnosis. We use Mammo phantom and photograph in F/S System methods and DR System methods. Each image uses the basis of assessment of evaluation tests and 10 people radiation students are visible fiber, Calcification and mass degree score. It compared the average score of each received image, then it classified the above schedule score with passing. The cellulose (fiber), the calcareous sinter (calcification)and the bell lump (mass) received a high score in DR and Film-Screen methods order. In this study, the breast image of DR methods had a better picture quality compared to the breast image of Film-Screen methods, and had received high score from all items. In DR methods, the image quality was dependent on the monitor resolution. The higher the monitor resolution, the better the quality of the image produced. According to quality control in Film- Screen methods, we found out that there was a decrease in the quality of the picture being produced.

방사능 오염으로 인한 유아 안전에 대한 유치원 교사의 인식

양진희(Jinhee Yang),박윤(Yun Park),여화연(Hwayeon Yeo) 한국방사선학회 2013 한국방사선학회 논문지 Vol.7 No.3

본 연구는 2011년 일본 후쿠시마 원자력 발전소 방사능 누출사고가 방사능 오염으로 인한 유아안전에 대한 유치원 교사의 인식에 미치는 영향을 분석하고, 유아안전 대책마련을 위한 기초자료를 제공하는 데 의의가 있다. 본 연구는 2013년 2월 C도의 공ㆍ사립유치원 교사 197명을 대상으로 설문지를 배부하여 회수된 134명의 자료를 분석하였다. 본 연구의 결과, 일본 원전사고는 방사능 오염으로 인한 유아안전에 대한 교사의 불안감에 영향을 미쳤으나, 방사능 오염으로 인한 유아안전에 대한 유치원 교사들의 안전지식과 대처방안은 낮은 것으로 나타났다. 결론적으로 방사능 오염으로부터 유아안전을 위한 하나의 방안으로 유아교사교육이 요구되며, 유아안전을 위한 대책 마련이 시급하다. The purpose of this study was to examine the impact of the Fukushima nuclear power plant accident of Japan in 2011 on kindergarten teachers' perception on young children's safety due to radioactive contamination. This study analysed the 134 questionnaire forms out of 197 kindergarten teachers in the region of Chungbuk. The findings of the study indicated that the Japanese unclear power plant accident exerted an influence on anxious of kindergarten teachers on young children's safety due to radioactive contamination. In conclusion, kindergarten teacher education are required to improve the safety knowledge of kindergarten teachers and alternative resolution method for young children's safety due to radioactive contamination.

방사능 오염식품과 방사선조사 식품에 관한 유치원 부모의 인식

양진희(Jinhee Yang),박윤(Yun Park),여화연(Hwayeon Yeo) 한국방사선학회 2012 한국방사선학회 논문지 Vol.6 No.6

본 연구는 2011년 일본 후쿠시마 원자력 발전소 방사선 누출사고가 방사능 오염식품과 방사선 조사식품에 관한 유치원 부모의 인식에 미치는 영향을 분석하여 국민건강자료를 제공하는데 의의가 있다. 본 연구는 2012년 8월 J시의 K와 M유치원의 학부모 205명을 대상으로 설문지를 배부하여 회수된 178명의 자료를 분석하였다. 본 연구의 결과, 일본 원전사고는 방사능 오염식품에 대한 학부모의 불안감에 영향을 미쳤으며, 방사선조사 식품에 대한 부모들의 인식은 낮았다. 결론적으로 방사선조사 식품에 대한 유치원 부모들의 인식을 높이고, 방사능 오염식품과의 명확한 구분 및 올바른 인식을 돕는 적극적인 홍보와 부모교육이 이루어져야 할 것이다. The purpose of this study was to examine the impact of the Fukushima nuclear power plant accident of Japan in 2011 on kindergarten parents' perception about irradiated foods and radioactive-contaminated foods. This study analysed the 178 questionnaire forms out of 205 parents of 'K' and 'M' kindergarten in the region of 'J' city. The findings of the study indicated that the Japanese nuclear power plant accident exerted an influence on anxious of kindergarten parents about irradiated foods and radioactive-contaminated foods. In conclusion, The full-fledged publicity and parent education are required to improve the perception and understanding of kindergarten parents about irradiated foods and the differences between it and radioactive-contaminated foods.

1.5T와 3.0T MRI에서 Saline Phantom을 이용한 자장 균일도 비교 분석

민정환 ( Jung Whan Min ),박훈희 ( Hoon Hee Park ),여화연 ( Hwa Yeon Yeo ),동경래 ( Kyung Rae Dong ) 조선대학교 공학기술연구원 2013 공학기술논문지 Vol.6 No.1

MRI generates a radio frequency (RF) pulse after setting the body in position in a large Gantry that generates a magnetic field. The signal is released by resonance of inner body``s hydrogen nucleus. This technology reorganizes and records the difference of the signal through the Computer. Recently, the use of 1.5T and 3.0T has been increased in the hospitals because 3.0T has higher Signal to noise ratio (SNR) compared to the 1.5T. To confirm the difference of magnetic field according to changes in magnetic field intensity, we used Saline Phantom. We compared SNR to magnetic field uniformity of 1.5T and 3.0T to improve the diagnostic value of image. According to size Field of view (FOV) of MRI equipment, we made a Saline Phantom ourselves. Using the Saline phantom to compare the magnetic field uniformity of 1.5T and 3.0T, we then obtained Axial and Sagittal images. According to the result of experiment, we confirmed that the numerical value of SNR using saline phantom decreased relatively as it went far away from the center of the magnetic field. In other words, a magnetic field become uneven bit by bit as it comes apart from the center. When comparing 1.5T with 3.0T, we figured out that as the intensity of a magnetic field rises, it becomes uneven. The experiment above tells us that magnetic field uniformity of MRI showed some difference depending on the location, isocenter or periphery of the magnetic field; and if the magnetic field uniformity goes off the range, distortion of the image happens. This means that even through without the complicated and highpriced equipments, it is possible to check the efficiency of MRI using simple Saline Phantom which we made by ourselves.

일반촬영 테이블 재질 특성에 관한 연구

김창복 ( Chang Bok Kim ),동경래 ( Kyung Rae Dong ),여화연 ( Hwa Yeon Yeo ) 조선대학교 공학기술연구원 2014 공학기술논문지 Vol.7 No.2

This study is intended to determine suitability of acryl, which has been the table material of general shooting, in line with its purpose or other available material securing better suitability than acryl among several other materials available in actual uses. Possible materials for the table used in general shooting, including acryl as the existing material, wood, plastic, glass, and pulps were compared by measuring transmittance and scattered dose by a dosimeter. Every material was prepared to have an identical thickness of 1 cm, and measurement for transmittance was conducted with fixed amperage at 100 mA while changing the voltage to 40 kVp, 60 kVp, 80 kVp, 100 kVp, and 120 kVp while measuring scattered dose for the side-scatter ray under the identical conditions excepting FFD. FFD was kept changing for the measurement. The transmittance of wood was highest when FFD was 100 cm, followed by those of acryl, pulps, plastic, and glass, and the results were identical at FFD 180 cm. As results of side-scatter ray measurements, acryl showed the highest value at FFD 30 cm, followed by wood, pulp, glass, and plastic. When considering the overall results, wood was the best material for transmittance while acryl was the best for the side-scatter ray. Though confirming the suitability of wood as the table material in consideration of transmittance and side-scatter ray was somewhat obstructive, this study could observe less level of side-scatter ray in wood than that of acryl. If only the side-scatter ray is considered, wood is the better candidate for the table material, but the properties of wood seemed to be subject for instability by serious environmental factors than others. As shown in the above, a wooden table may result in less exposure of patients to scattered ray than that of acryl, but it has a risk of degradation and consecutive infection so that the acryl is assumed to be the most suitable material for the table for general shooting in a comprehensive view among other materials.

일반촬영장치의 정도관리 연구

강병삼 ( Byung Sam Kang ),박훈희 ( Hoon Hee Park ),동경래 ( Kyung Rae Dong ),여화연 ( Hwa Yeon Yeo ) 조선대학교 공학기술연구원 2013 공학기술논문지 Vol.6 No.4

Thanks to the rapid increase of the interest in the quality control of the General X-ray systems, this research proposes the direction of the quality control through comparing and inspecting the actual condition of the respective quality control in the Clinic, the educational institution and the hospital. The subjects of the investigation are diagnostic radiation equipment``s in the clinic, the educational institution and the hospital around the capital. A test of kVp, mR / mAs out put test and reproducibility of the exposure dose, half value layer, an accordance between the light field and the beam alignment test, and lastly reproducibility of the exposure time. Then the mean difference of the percentage, the CV (Coefficient of Variation, CV) and the attenuated curve which are respectively resulted from the above tests are computed. After that we have evaluated the values according to the regulations on the Diagnostic Radiation Equipment Safety Administration regulations. In the case of the clinic and the educational institution, there were 42 general X-ray devices. And 14.28% of the kVp test, 11.9% of the reproducibility of exposure dose test, 7.14% of the mR/mAs out put test, and 7.14% of the HVL (Half Value Layer) test appeared to be improper. In the case of the hospital, however, there were 28 devices. And 7.14% of the reproducibility of exposure dose, 7.14% of the difference in the light field/ beam alignment, and 7.14% of the reproducibility of the exposure time appeared to be improper. According to the investigation, the hospital``s quality control condition is better than the condition in the clinic and the educational institution. The quality control condition of the general X-ray devices in the clinic is unsatisfactory compared to the hospital. Thus, it is considered that realizing the importance of the quality control is necessary.

Fat Suppression에 대한 fast spin echo fat saturation와 IDEAL - FSE 기법의 유용성 비교 연구

박용순 ( Yong Soon Park ),문일봉 ( Il Bong Moon ),동경래 ( Kyung Rae Dong ),여화연 ( Hwa Yeon Yeo ) 조선대학교 공학기술연구원 2014 공학기술논문지 Vol.7 No.1

This study is intended to implement images using fast spin echo fat saturation and IDEAL techniques as the fat suppression of reducing fat signal phase artifact caused by chemical shift phenomena on the boundary interface between water and fat, and the consecutive qualitative analysis was carried out in order to compare the availabilities of those imaging techniques. The comparison was conducted by applying the fast spin echo (FSE) T2 weighted pulse sequence and IDEAL techniques to the test. 1.5 Tesla MR scanner (Signa HDxt, GE, USA) and 16 channel CTL coil were employed in the test as the MR imaging devices. For image point, FSE technique was applied to gain images as follows: TR as 2617 / 4250 ms, TE as 85 / 110 ms, Matrix as 320 × 192 / 320 × 224, ETL as 22 / 24, FOV as 330 ㎜, and slice thickness as 40 mm. For those by IDEAL technique, the image implantation was carried out under the following conditions: TR as 4250 ms, TE as 110 ms, FOV as 330 ㎜, Slice thickness as 40, Matrix as 320 × 224, ETL as 24, Band width as 62.50 ㎐, and NEX as 2. As the qualitative analysis method, the signal to noise ratio and the contrast to noise ratio were obtained from the areas of interest in each group, and the values among each group were comparatively analyzed to determine the higher availabilities between the fast spin echo fat saturation and IDEAL-FSE techniques for the fat suppression. As results of imaging, the SNR values of fat at the given points for FSE technique were 0.933, 0.926, 0.953, and 0.956, respectively, while that for IDEAL technique was 0.97. The SNR values for water for FSE technique were 0.316, 0.233, 0.296, and 0.196, respectively while that for IDEALtechnique was 0.44. The required time for FSE technique were 1 minutes 40 seconds, 2 minutes 54 seconds, 1 minute 29 seconds, and two minutes 54 seconds while that for IDEAL technique was four minutes 28 seconds. When FSE imaging and IDEAL techniques that used the identical image points with IDEAL technique were compared among other FSE techniques, SNR of IDEAL technique was 1.017 times of that in FSE, and the time requirement was 3.011 times larger. Though IDEAL technique required 3.011 times longer time than that of FSE T2 technique, but SNR was just 1.017 time higher while CNR became 0.896 times lower. Implication by the study results may include that IDEAL technique may be used to obtain images of uniform fat suppression with excellent SNR, but FSE T2 needs to be used to promote the convenience of patients based on relatively short test time.

CT 검사에서 Aluminum Foil을 이용한 수정체 차폐에 대한 유용성평가

김현수 ( Hyun Soo Kim ),손진현 ( Jin Hyun Son ),여화연 ( Hwa Yeon Yeo ),동경래 ( Kyung Rae Dong ) 조선대학교 공학기술연구원 2013 공학기술논문지 Vol.6 No.1

The aim of this study is to assess the radiation dose reduction of eye lens using aluminum foil shield. We also evaluated dose reduction and the effect on image quality using aluminum foil eye shield when performing head Multi Detector Computed Tomography (MDCT). Examinations were performed with a 256 MDCT scanner, and then compared the shielded/unshielded lens dose. The examination was performed with and without aluminum foil shielding using CT Head phantom and CT ionization chamber. We carried out image quality of aluminum foil``s thickness using AAPM CT phantom and Head phantom. The mean radiation doses to the eye with the shield and to those without the shield were 29.3 mGy versus 27.4 mGy, respectively. The lens shield had about 6.5% decrease in radiation dose to the lens. We did not see any differences in the quality of images between the shielded and unshielded brain. So, effective eye lens radiation dose reduction using the aluminum foil is less than the bismuth. But the eye and head CT recommend the use of shields by the principle of ALARA.