조영제 부작용 분석

하동윤(Dong Yoon Ha),김경숙(Kyoung Sook Kim) 대한CT영상기술학회 2006 대한CT영상기술학회지 Vol.8 No.1

Purpose To evaluate the prevalance rate and symptoms of risk factors of the adverse reactions m patients after contrast injection during CT examinations. Materials and Methodes Between january 2005 and december 2005, 103, 343 patients who received intravenous contrast administration during CT scans at Asan Medical Center. We evaluated the prevalance rate, symptoms of risk factors of the adverse reactions in patients based on reviewing medical records. Results The results of this study are as follows; 1. Adverse reactions occurred in 447 of 103,343 patients(0.43%). 2. Incidencs of severe adverse reactions occurred in 171 of 103,343 patients(0.17%) and very severe adverse reactions occurred in 1 of 103,343 patients(0.0001%). 3. Clinical signs of adverse reactions were most commonly dermatologic problems(40.4%) such as urticaria and itching, followed by systemic problems(30.5%), nervous problems(9.6%), respiratory problems(9.5%), and so on. Conclusions Serious adverse reaction to CM are fortunately fatal reactions are extremely rare with incidence of 1 in 170,000 contrast examinations. History of previous serious reaction to contrast media, bronchial asthma or multiple allergies are important risk factors for developing major reactions to contrast administration. A voiding contrast media administration in patients at high risk of serious reaction is advisable but if the administration is deemed essential all precautions should be implemented and measures to treat serious reactions should be rapidly available.

투시 검사 시 장비에 따른 환자와 시술자의 입사표면선량 연구

양해두,홍선숙,성민숙,하동윤,Yang, Hae-Doo,Hong, Seon-Sook,Seong, Min-Sook,Ha, Dong-Yoon 대한디지털의료영상학회 2013 대한디지털의료영상학회논문지 Vol.15 No.2

Purpose : Fluoroscopy equipment, depending on the type of changes that occur in the patient's position ESD and study the patient's scatter ray of ESD Practitioners considered a comparative analysis was to evaluate the correct dose. Materials and Methods : HITACHI four overtube type TU-8000 Flat Detector and Under tube C-Arm Philips' Multi Diagnost Eleva with Flat Detector type were measured by. Each devices is a measure of the patient's esd randophantom position in tabel unfors Xi multi funtion then fixed to the abdomen fluoroscopy and 10 seconds, spot was measured three times, practitioners of the incident surface dose by considering the patient's scatter ray of the table for each device in the average human stomach 21cm thickness acrylic phantom ($25cm{\times}25cm$) Place the practitioner position after position randophantom unfors Xi multi funtion in the thyroid and stomach 1 minute by a fixed one-time fluoroscopy and measured. Results : 10 seconds and the patient perspective of the c-arm ESD 1.2 times smaller on the AP and oblique measurements were measured in the 6-13 times smaller. spot positions to changes in the measured three times on the AP of the abdomen, ESD is 18 times smaller c-arm measurements and the oblique measurement was 19-30 times smaller. And 1 minute at practitioners fluoroscopy esd in the thyroid 2.12 times the c-arm, chest 1.75 times less the dose was measured. On the AP, depending on the device, but the lack of dose difference oblique positions of the two devices depending on changes in the area due to changes in both the AP than on the dose increased, the difference in dose between the two devices, the maximum difference was approximately 27 times. Conclusion : Fluoroscopic equipment at the time of inspection in accordance with changes in dose according to the patient and the patient's positions changes, because the area of the scatter ray considering the change of dose measurements be made, and study of the equipment according to the characteristics of the efficiency and the exposure of the patient and practitioner is considered smooth study equipment manufacturers that can be done is to build the system and think that is also important. Various fluoroscopy when you check future changes in many factors of change in dose for the equipment in the laboratory system by considering the scatter ray radiation shielding for the management to take advantage of reckless undertube have been utilized as more exposure Reduction activities can help is considered as the direction.

복부일반촬영시 선원과 검출기간의 거리변화에 따른 영상 화질 및 피폭선량에 관한 연구

장지성,최원근,정재연,이관섭,하동윤,Jang, Ji-Sung,Choi, Weon-Keun,Jung, Jae-Yon,Lee, Kwan-Sub,Ha, Dong-Yoon 대한디지털의료영상학회 2012 대한디지털의료영상학회논문지 Vol.14 No.2

Purpose : The purpose of this study was to reduce Entrance Surface Dose and maintain image quality by changing Source to Image receptor Distance. And we'd like to compare ESD on this study to DRLs in other contries. Materials and Methods : We used indirect DR system(Definium 8000, General Electric, USA)and phantom(ART-200X, Flukebiomedical, USA),glass dosimeters(GD-352M, Asahi Techno Glass, Japan)for this study. The imagies were obtained throuh 80kVp fixed, and different tube currents using AEC mode in $16{\times}16$(inch) field size and changing Source to Image receptor Distance from 100 cm to 130 cm per 10 cm unit. The phantom with attaching 5 glass dosimeters on abdomonal skin was set at supine and erect position as a anterioposterial projection on detector For measuring Entrance Surface Dose. Image analysis was conducted by histograms of Image J(1.46r) which was given from National Institutes of Health(NIH). Results : Due to inverse square law of distance, the tube currents were increasing 42.6 % in supine position and 32.6 % in erect position according to the change of Source to Image receptor Distance. While Entrance Surface Doses were rapidly decreasing 14.2 % in supine position and 29.4 % in erect position according to the change of Source to Image receptor Distance. As the results of histogram using Image J, pixel mean values from 100 cm to 110 cm, 120 cm and 130 cm were decreasing each 1.4%, 2.5%, 2.7%, 4.5%, 2.2 %, 5.8 % in supine, erect position. While standard deviations from 100 cm to 110 cm, 120 cm and 130 cm were increasing each 1.4 %, 2.5 %, 2.5 %, 4.0 %, 2.0 %, 4.9 % Consequently, there are no significant differences in abdomen images taken. Conclusion: As the results described above, we strongly recommend using long Sourceto Image receptor Distance than 100cm that we have been using. So, we should deliver less Entrance Surface Dose to the patients while maintaining image quality in abdomen radiography.

투시 검사 시 체위 변화에 따른 입사표면선량의 평가 연구

양해두,홍선숙,박은성,성민숙,하동윤,Yang, Hae-Doo,Hong, Seon-Sook,Park, Eun-Seong,Seong, Min-Sook,Ha, Dong-Yoon 대한디지털의료영상학회 2011 대한디지털의료영상학회논문지 Vol.13 No.4

This study intends to investigate patients' exact exposure doses by comparatively measuring ESD (Entrance Surface Dose) with the DAP meter, which excludes scattered rays, and ESD with the Xi multifunction meter, which includes scattered rays, by posture changes for Esophagography test and UGI test. The materialwere examined through Sonialvision-SafireII SPEC overtube system. ESD was measured by using the DAP meter, and as a tool to measure ESD including scattered rays on the plane of incidence of human phantom, the Xi multifunction meter was used. The average fluoroscopic time of Esophagography test was 4.192 minutes and the average number of images was 47.7, while the average fluoroscopic time of UGI test was 6.881 minutes and the average number of images was 37.8. The ratios of the incident dose of DAP meter and the ESD of Xi meter were calculated bydividing the fluoroscopic time and the number of images by each posture change. As for Esophagography test, the dose increased by 21.6~55.5% in the fluoroscopic test and by 4.8~24.7% in the spot test. In the front spot test, however, the does increased by as little as 5.3%. As for UGI test, the dose increased by 21.1~49.5% in the fluoroscopic test and by 10.1~34.9% in the spot test. It is expected that measuring doses in consideration of scattered rays by posture changes will be an important index in evaluating and managing patients' exact exposure doses for each test above. Furthermore, it is judged that this sort of study is inevitable and desirable to reduce patients' exposure doses after all.

Dual Source CT와 Multi Detector CT에서 Coronary 검사의 방사선량 분석

권성옥(Seong Ohk Kwon),하동윤(Dong Yoon Ha),최준호(Joon Ho Choi),이상우(Sang Woo Lee),서동수(Dong Soo Suh) 대한CT영상기술학회 2007 대한CT영상기술학회지 Vol.9 No.1

Purpose This study compared an exposure dose of DSCT with MDCT in cardiac CT and we analyzed how much the radiation dose increased or decreased. Materials and Methods For an experiment, CT device for the human body was used by 16 channel MDCT(Multi Detecter CT) manufactured by siemens and DSCT(Dual Source CT) called by SIEMENS Somatom Definition CT. It is available for supplying two source with each different kVp and mAs, processing and gathering the data at the same time. we used ECG Simulator(Marquette Electronics. USA) for examining a change of Heart Rate. An experiment method compares CTDIvol and CTDIDLP of DSCT with MDCT and is to measure. it was performed by using ECG Simulator in DSCT Coronary study, giving Heart Rate with a variety of numerical value, such as 50bpm, 55bpm, 60bpm, 65bpm, 70bpm, 75bpm, 80bpm, 85bpm, 90bpm, 95bpm, 100bpm, 105bpm, 110bpm, according to high or low of each heart rate, comparing and measuring CTDIvol and CTDIDLP, we can know whether there is some differences. Results 1. The Coronary study protocol of MDCT is 120kVp, 600mAs, Rotation time 0.37sec, Scan Time 18~20sec. CTDIvol and CTDIDLP measured each 46.80mGy, 936mGy. The Coronary study protocol of DSCT is 120kVp, 300mAs, Rotation time 0.33sec, Scan Time 8~10sec. CTDIvol and CTDIDLP measured each 47.45mGy, 427.05mGy. As a result, CTDIDLP was reduced about 55% in DSCT compared with Multi Detecter CT though CTDIvol is similar. 2. Heat rate of Coronary Study used ECG Simulator in DSCT is 50bpm, 55bpm, 60bpm, 65bpm, 70bpm, 75bpm, 80bpm, 85bpm, 90bpm, 95bpm, 100bpm, 105bpm, 110bpm. according to high or low of each heart rate, CTDIvol is measured to 60.81mGy in 50bpm and 29.llmGy in 110bpm. 3. CTDIvol and CTDIDLP of MDCT used Coronary study protocol is measured to 46.80mGy and 936mGy. measured CTDIvol of DSCT is 29.11~60.81mGy in 50bpm ~110bpm heart rate and CTDIDLP is measured to 261.99~547.29mGy. Conclusion The Dual Source CT is increased 29.9%~0.1% of CTDIvol in 50bpm ~ 110bpm compared with the Multi Detecter CT. And the CTDIvol in 70bpm ~ 110bpm was reduced by 9%~37.8. In the Single Source the Table speed came to be late as a heart rate increase. On the other hand, The Table speed of DSCT did fast according to the increase of the Heart Rate and The Scan time is reduced. When heart rate is slow, CTDIDLP of Dual Source CT is reduced by 41.6 % compared with Multi Detecter CT and When heart rate is fast, CTDim.P of Dual Source CT is reduced by 72.1% compared with Multi Detecter CT.

CT검사시 소아환자의 적정 촬영조건에 관한 연구

권성옥(Seong Ohk Kwon),하동윤(Dong Yoon Ha),이희정(Hee Jeong Lee),김선기(Seon Ki Kim),서동수(Dong Soo Suh),장동수(Dong Soo Chang) 대한CT영상기술학회 2005 대한CT영상기술학회지 Vol.7 No.1

Purpose In this study, In order to decrease of exposure rate and attain better image quality for protect pediatric patients. We investigated to find the optimal exposure factors for pediatric patients in computed tomography. Materials and methods : We performed this study to assesment exposure rates from using the pencil type Ionization chamber. We are using the 16 channel multi detector computed tomography(16-MDCT) on General Electric Lightspeed ultra 16. In this Experimental phantom made of each brain and abdomen types to 5kg, 5~10kg, 10~20kg, 20~40kg, 40~60kg, more 60kg etc(Standard of korea child growth 표). Results The results obtained were as followed : 1) Optimal Exposure factor of brain Phantom is : 100kVp~120kVp, 160mA~200mA(Weighting steps) 2) Optimal Exposure factor for Abdomen Phantom is : 80kVp~100kVp, 60mA~180mA(Weighting steps) 3) Measured Exposure rates : 10%~180%,(using the adult Exposure factor) 4) Measured Exposure rates : -30%~110%,(decease of one steps Exposure factor) 5) Abdomen Phantom Exposure rates is more than brain Phantom caused of beam hardening artifact in brain. Conclusion From the results of these studies, It is suggested that which are using the optimal exposure factor to decrease exposure rate and attain better image quality for protect pediatric patients. We are need to standard official certification in order to avoid of radiation hazard.

전 척추 전.후 방향 검사 시 AEC Mode와 Fix Mode에서 PC-Based Monte Carlo Program을 이용한 장기선량 및 유효선량 평가

김정진,장성원,박장흠,이관섭,하동윤,Kim, Jeong Jin,Jang, Seong Won,Park, Jang Heum,Lee, Kwan Seob,Ha, Dong Yoon 대한디지털의료영상학회 2012 대한디지털의료영상학회논문지 Vol.14 No.2

There are AEC mode and fix mode to exposure when the whole spine antero-posterior radiography is done by using DR equipment. This study compared the utility of fix mode to AEC mode, by evaluating organ dose and effective dose and by examining the quality of radiographic image. GE DEFINIUM 8000 and ART-200X Rando Phantom manufactured by Flukebiometical were used for this study. The Rando phantom was set in front of wall detector of X-rays equipment. AEC mode was set at 80kVp and Fix mode was set at 80kVp, 25mAs, 32mAs, 40mAs, and 50mAs. Whole spine AP image were aquired by combining C, T-L and L-S spine images obtained through 3 exposures. When obtaining C, T-L and L-S spine images, were checked for Air kerma (mGy) value calculated by UNFORS Xi meter attached at the phantom surface of center of radiation field. The effective and organ doses were compared by PCXMC program (PC-Based Monte Carlo Program). The quality of obtained radiographic image was evaluated visually by 3 radiologists using resolution chart. When the effective doses was calculated based on tissue weighting factor of ICRP-103, 1.278mSv was measured by AEC mode, and Fix mode measured 0.405mSv at 25mAs, 0.518mSv at 32mAs, 0.649mSv at 40mAs, and 0.810mSv at 50mAS. In addition, the organ dose measured with esposure at 25mAs by Fix mode was almost equivalent to the organ dose by AEC mode, at the esophagus, thyroid, oral mucosa, salivaly glands located at the cervical spine part, while the organ dose by Fix mode was in general lower than the organ dose by AEC mode at the other organs. When Fix mode at 32mAs, 40mAs, and 50mAs was compared to AEC mode for organ dose in 26 organs, AEC mode had higher measurement in 21 organs but not for than brain, trachea, thyroid, oral mucosa, and salivaly glands which are located at the cervical spine part. The image quality evaluated by resolution test chart was much higher with AEC mode than the quality with Fix mode at all exposure conditions. However, while the image quality of cervical spine exposured at 50mAs by Fix mode was lower than the quality of AEC mode, thoraco-lumbar spine and lumbo-sacral spine were calculated and the quality was similar to AEC mode. Scoliosis occurs mainly at thoraco-lumbar and lumbo-sacral spine, not at cervical spine. Compared to AEC mode, Using the appropriate protocol (80kVp, 50mAs) of fix mode for whole spine AP radiography was thought to be useful because the image quality of the thoraco-lumar and lumbo-sacral spine was similar on AEC mode, Also organ and effective doses can be decreased with Fix mode. Therefore, It is considered that fix mode can be used properly with AEC mode for whole spine AP radiography when considering patient's body posture.

C-arm의 Tube 위치에 따른 거리 및 방향별 피폭선량 비교

김진수,우봉철,김성진,이관섭,하동윤,Kim, Jin-Su,Woo, Bong-Cheol,Kim, Sung-Jin,Lee, Kwan-Sup,Ha, Dong-Yoon 대한디지털의료영상학회 2009 대한디지털의료영상학회논문지 Vol.11 No.1

In operation room, the use of the C-arm unit is increasing. So, the radiation dose of the person who work in operation room was even more increased than before. Thus, this study is shown the measurement of expose dose and the way for decrease of the radiation dose by using the C-arm unit. The experiment was performed with the C-arm unit and used a phantom which is similar to tissue of the human body and fluoro-glass dosimeter for dose measurement. The expose dose were measured by the tube position(over tube, under tube) of the C-arm unit, distance(50, 100$\sim$200cm), direction(I, II, III, IV), runtime(1min, 3min), wearing of the apron. The radiation dose was decreased twice and three times at under tube rather than over tube. The I direction was measured 20$\sim$30% more than the others. The biggest expose dose is 50cm from center on distance. The expose dose is decreased to far from center. In case of Wearing of the apron, the radiation dose was decreased 60$\sim$90% by the distance. But there weren't change of the radiation dose by C-arm tube position. In present, by increasing the usage of the C-arm unit, the radiation dose is inevitable. So, this study recommends us to use the under tube of the C-arm unit. Also, Wearing of the apron is required for minimum of the radiation exposure.

고령화된 매립지에서 발생되는 침출수의 처리방안

권철웅(Cheol Woong Kwon),조순행(Soon Haing Cho),최영수(Young Soo Choi),하동윤(Dong Yun Ha),윤계섭(Kye Sup Yoon) 大韓環境工學會 1997 대한환경공학회지 Vol.19 No.3

Glass Dosimeter를 이용한 환자피폭선량에 관한 분석

김재인,최원근,장성원,오창섭,이관섭,하동윤,Kim, Jae-In,Choi, Won-Keun,Chang, Sung-Won,Oh, Chang-Seop,Lee, Kwan-Sup,Ha, Dong-Yoon 대한디지털의료영상학회 2009 대한디지털의료영상학회논문지 Vol.11 No.1

Far reducing medical radiation exposure and managing patient doses, Entrance surface doses(ESDs) were measured at Diagnostic Radiology Department in ASAN medical center, also we determined and compared with the Diagnostic Reference Level(DRL) of some other countries. ESDs were measured far the most common types of X-ray procedures, such as chest PA, lumbar spine AP, lumbar spine lateral, Pelvis AP, Skull PA. ESDs were measured by Glass dosimeter and Unfors Xi meter. Those were applied collimation center of phantom's entrance skin surface. The results of ESDs were compared Glass dosimeter with Unfors Xi meter. Those were measured within 5% statistical difference. It seemed well agreement at two devices. In most cases ESDs measured far the different types of X ray procedures were found to be lower than the DRL of IAEA, but ESDs on chest PA, lumbar spine AP, lumbar spine lateral, Pelvis AP, Skull PA were proximity ar excesses at DRL of advanced country. Through this study, we need an investigation and improvement at present diagnostic radiology exam system. Also, radiologists make an effort to reduce patient dose and having a technical skill.