방사선치료계획을 위한 PET 종양용적 결정 연구: 컴퓨터 모의실험

윤석남,조철우,이재성,Yoon Seok Nam,Joh Chul-Woo,Lee Jae Sung 한국의학물리학회 2005 의학물리 Vol.16 No.4

PET 기기의 보급이 급속도로 증가하고 있으며 여러 임상 및 연구 분야에서 그 유용성이 입증되어 널리 이용되고 있다. 이 가운데서도 종양 진단 분야에서 PET의 활용도는 매우 높아 대부분의 PET검사를 종양 검사가 차지하고 있으며 특히 양성과 악성종양의 감별, 종양의 치료효과 판정 및 종양의 재발진단 등에 널리 이용되고 있다. 최근에는 PET과 CT를 결합한 PET-CT의 사용이 증가됨에 따라 방사선치료분야에서 PET의 활용에 대한 관심이 커지고 있다. 방사선치료를 위한 종양의 경계를 결정하기 위하여 해부학적인 영상인 CT를 이용하는 것이 보편적이나 이 경우 실제 암조직에 상관없이 모양만을 기준으로 삼으므로 암조직에 대한 방사선 치료 용량이 많거나 적을 수 있어 적절한 치료가 되지 않을 수 있다. 따라서 PET을 이용한 기능적이고 살아 있는 암조직의 정확한 용적 측정은 적절한 치료 지표를 줄 수 있어 매우 중요한 일이나 상대적으로 낮은 공간해상도에 의해 정확한 경계를 결정하기 어려운 문제가 있다. 이 연구에서는 실제 종양의 용적을 구할 수 있는 영상화소 값의 역치가 변변의 크기, PET 기기의 공간해상도, 병변 대 주변 섭취비에 어떠한 영향을 받는지를 평가하기 위한 컴퓨터 모의실험을 수행하였다. The utilization of PET has been increased so fast since the usefulness of the PET has been proved in various clinical and research fields. Among the many applications, the PET Is especially useful in oncology and most of the clinical PET scans are peformed for the oncologic examination Including the different diagnosis of malignant and benign tumors and assessment of the treatment effects and recurrent tumors. As the PET-CT scanners are widely available, there is Increasing interest in the application of the PET Images to the radiation treatment planning. Although the CT images are conventionally used for the target volume determination in the radiation treatment planning, there are fundamental limitation In use of only the anatomical information. Therefore, the volume determination of the functionally active tumor region using the PET would be important for the treatment planning. However, the accurate determination of the tumor boundary is not simple in PET due to the relatively low spatial resolution of the currently available PET scanners. In this study, computer simulations were peformed to study the relationship between the lesion size, PET resolution, lesion to background ratio and the threshold of Image Intensity to determine the true tumor volume.

급성심근경색환자의 심근생존능 평가에 있어서 T1-201 재분포영상과 24시간 재주사영상의 역할

윤석남,배문선,박찬희,윤명호,최병일 ( Seok Nam Yoon,Moon Sun Pai,Chan H Park,Myung Ho Yoon,Byung Il William Choi ) 대한핵의학회 1998 핵의학 분자영상 Vol.32 No.4

Purpose: We evaluated the importance of redistribution and 24 hour reinjection images in Tl-201 SPECT assessment of myocardial viability after acute myocardial infarction (AMI). Materials and Methods: We performed dipyridamole stress-4 hour redistribution-24 hour reinjection Tl-201 SPECT in 43 patients with recent AMI (4-16 days). The myocardium was divided into 16 segments and perfusion grade was measured visually with 4 point score from 0 to 3 (absent uptake to normal uptake). A perfusion defect with stress score 2 was considered moderate. A defect was considered severe if the stress score was 0 or l (absent uptake or severe perfusion decrease). Moderate defect on stress image were considered viable and segments with severe defect were considered viable if they showed improvement of 1 score or more on redistribution or reinjection images. We compared the results of viability assess-ment in stress-redistribution and stress-reinjection images. Results: On visual analysis, 344 of 688 segments (50%) had abnormal perfusion. Fifty two (15%) had moderate perfusion defects and 292 (85%) had severe perfusion defects on stress image. Of 292 severe stress defects, 53 were irreversible on redistribution and reversible on reinjection images, and 15 were reversible on redistribution and irreversible on reinjection images. Two hundred twenty four of 292 segments (76.7%) showed concordant results on stress-redistribution and stress- reinjection images. Therefore 24 hour reinjection image changed viability status from necrotic to viable in 53 segments of 292 severe stress defect (18%). However, myocardial viability was underestimated in only 5% (15/292) of severe defects by 24 hour reinjection. Conclusion: The 24 hour reinjection imaging is useful in the assessment of rnyocardial viability. It is more sensitive than 4 hour redistribution imaging. However, both redistribution and reinjection images are needed since they complement each other. (Korean J Nucl Med 1998;32:325-31)

近代韓國語における日本製漢語の考察

윤석남 ( Seok Nam Yoon ) 한국현대언어학회 2007 언어연구 Vol.23 No.2

PET을 이용한 심근생존능의 평가

윤석남 ( Seok Nam Yoon ) 대한핵의학회 2005 핵의학 분자영상 Vol.39 No.2

급성심근경색 환자에서 역재분포를 보인 심근의 Thallium 재주사에 의한 생존능의 평가

윤석남(Seok Nam Yoon),배문선(Moon Sun Pai),박찬희(Chan H Park) 대한핵의학회 1998 핵의학 분자영상 Vol.32 No.6

N/A Purpose: The aim of this study was to evaluate whether T1-201 reinjection distinguishes viable from non-viable myocardium in patients with reverse redistribution after acute myocardial infarction. Materials and Methods: We studied 42 patients with acute myocardial infarction (age, 55±12 years). Eighteen (43%) out of 42 showed reverse redistribution on dipyridamole stress-4 hour redistribution T1-201 single photon emission computed tomography (SPECT). T1-201 reinjection was performed at 24 hours. Reverse redistribution was defined as worsening of perfusion defect at 4 hour delayed scan. All patients underwent follow-up echocardiography in 4 months to assess regional wall motion improvement. T1-201 uptake on reinjection images were analyzed for the prediction of myocardial wall motion improvement. Results: Of 36 segments with reverse redistribution, 17 segments showed normal wall motion on echocardiography, while 19 segments showed all motion abnormalities. Of 19 the segments with reverse redistribution, 11 (58%) showed enhanced uptake after 24 hour reinjection. Myocardial wall motion was improved in 10 of 11 segments (90%) with enhanced uptake on reinjection. Wall motion improvement was not seen in 5 of 8 segments (63%) without enhanced thallium uptake. When myocardial viability was assessed by the uptake on reinjection image, nine of 10 segments (90%) with normal or mildly decreased uptake showed improved wall motion. Wall motion was not improved in 5 of 9 segments (56%) with severely decreased uptake. Conclusion: In patients with acute myocardial ifarction, T1-201 reinjection imaging on myocardial segments with reverse redistribution has a high positive predictive value in the assessment of myocardial viability

『西国立志編』の漢語の問題 : 両ルビ付き漢語を中心に

尹錫南(Yoon Seok-Nam) 한국일본문화학회 2003 日本文化學報 Vol.0 No.19

관동맥우회로술 후에 심근 SPECT에 나타난 관류의 악화 분석

이원우,이동수,윤석남,김기봉,정준기,이명철,고창순 ( Won Woo Lee,Dong Soo Lee,Seok Nam Yoon,Ki Bong Kim,June Key Chung,Myung Chul Lee,Chang Soon Koh ) 대한핵의학회 1997 핵의학 분자영상 Vol.31 No.1

Though myocardial perfusion was usually expected to improve after coronary artery bypass graft(CABG) surgery, some myocardial segments were aggravated after operation, as we compared perfusion changes on postoperative SPECT with preoperative ones. In this study, we evaluated perfusion changes after operation in rest and stress myocardial SPCET in 44 patients (M:F=25:19, age 57.1 year +- 8.2) who had CABG before and 3 months after operation. We tried to find out possible causes for perfusion aggravation with multivariate logistic regression analysis regarding whether bypass graft was artery or vein and which coronary artery territory was operated. Among 616 myocardial segments which were operated, 89(14.4%) aggravated after operation In the univariate analysis, myocardial segments in the left circumflex arteries(I Cx) aggravated more often(p<0.01) than others and segments having operative angioplasty did less often(p<0.01). Multivariate logistic regression revealedthat LCx was risk factor for perfusion aggravation [odds ratio=2.54 (95% confidence interval : 1.53-4.22, p<0.01)] However, this was not the case when we analysed in terms of arterial territories. Among 106 coronary rterial territories which were operated. 27(25.5%) aggravated. The territories having aggravated had similar characterstics regarding whether they received arterial or venous grafts. Angioplasty and whether the operated territories were left anterior descending. Right coronary or left circumflex arteries. In conclusion, myocardial segments in the left circumflex artery tended to aggravate more often after bypass surgery than the others. In short-term comparison of perfusion after surgery. We could not find any tendency that arterial or venous fraft was associated with more frequency of the affravation of perfusion after operation.

관상동맥 질환 진단에서 ATP 부하 T1-201 심근 관류 SPECT 의 안전성과 유용성

배문선,박찬희,윤석남,김원,김한수 ( Moon Sun Pai,Chan H Park,Seok Nam Yoon Won Kim,Han Soo Kim ) 대한핵의학회 1998 핵의학 분자영상 Vol.32 No.3

Purpose: ATP (adenosine triphosphate) is a potent coronary vasodilator with a rapid onset of action and a very short half-life. Myocardial perfusion scintigraphy with intravenous ATP has not yet been sufficiently proven in the diagnosis, follow-up, and risk stratification of coronary artery disease. The purpose of this study was to evaluate the safety, feasibility and diagnostic accuracy of pharmacologic stress thallium-201 myocardial SPECT using an intravenous ATP infusion in patients with suspected coronary artery disease. Materials and Methods: Thalliurn-201 myocardial SPECT in 319 patients with suspected coronary artery disease were performed after the infusion of ATP (0.08 mg/kg/min for 6 rnin). The adverse effects were carefully monitored. Coronary angiography was also performed within 3 weeks. Results: Although 76.5% of the patients had sorne adverse effects, they were transient, mild, and well tolerated. In all patients, the ATP infusion protocol was completed and only 2 patients required aminophylline. The adverse effects were dyspnea in 63%, headache in 31%, flushing in 21%, chest pain in 14% and abdominal discomfort in 5% of the patients. The sensitivity and specificity were 80% and 90% respectively. Conclusion: Thallium-201 myocardial SPECT after 6 min-infusion of ATP at a rate of 0.08 mg/kg/min is safe and has a diagnostic value in detecting coronary artery disease. (Korean J Nucl Med 1998;32:250-8)

Bottom 컬렉터와 단일 금속층 구조로 설계된 SiGe HBT의 전기적 특성

최아람,최상식,김준식,윤석남,김상훈,심규환,Choi, A-Ram,Choi, Sang-Sik,Kim, Jun-Sik,Yoon, Seok-Nam,Kim, Sang-Hoon,Shim, Kyu-Hwan 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.8

This paper presents the electrical properties of SiGe HBTs designed with bottom collector and single metal layer structure for RF power amplifier. Base layer was formed with graded-SiGe/Si structures and the collector place to the bottom of the device. Bottom collector and single metal layer structures could significantly simplify the fabrication process. We studied about the influence of SiGe base thickness, number of emitter fingers and temperature dependence $(<200^{\circ}C)$ on electrical properties. The feasible application in $1{\sim}2GHz$ frequency from measured data $BV_{CEO}{\sim}10V,\;f_T{\sim}14GHz,\;{\beta}{\simeq}110,\;NF{\sim}1dB$ using packaged SiGe HBTs. We will discuss the temperature dependent current flow through the e-b, b-c junctions to understand stability and performance of the device.

의사결정트리 프로그램 개발 및 갑상선유두암에서 질량분석법을 이용한 단백질 패턴 분석

윤준기 ( Joon Kee Yoon ),이준 ( Jun Lee ),안영실 ( Young Sil An ),박복남 ( Bok Nam Park ),윤석남 ( Seok Nam Yoon ) 대한핵의학회 2007 핵의학 분자영상 Vol.41 No.4