호흡에 의해 내부 움직임을 갖는 장기에 전달되는 선량에서 Time Gating Threshold (TGT)의 효과

김연래,정진범,정원균,홍세미,서태석,Kim Yon Lae,Chung Jin Bum,Chung Won Kyun,Hong Semie,Suh Tae Suk 한국의학물리학회 2005 의학물리 Vol.16 No.2

본 연구는 호흡에 따라 내부 장기가 움직일 때, 내부 장기가 가장 안정적인 구간의 문턱 값(threshold)을 시간으로 설정한 후 선량분포에 대한 연구를 수행하였다. 일반적으로 정상적인 호흡주기 중에서 시간대비 내부 장기 움직임이 호기 상태에서 적게 나타난다. 그러므로 시간동기 문턱 값(time gating threshold, TGT)은 내부 장기 움직임이 가장 적은 호기 시 1 초 동안 움직일 때의 선량분포를 평가하였다. TGT를 설정했을 때 선량분포를 비교하기 위해 다음 조건으로 방사선을 조사하였다. 내부 장기가 1) 고정된 상태, 2) 문책 값 범위 내에서 움직일 때, 3) 문턱 값 범위 밖에서 움직일 때, 각각의 내부 장기 움직임 조건을 구동팬톰시스템으로 모사하였다. 그리고 필름 선량 측정법(film dosimetry)을 이용하여 비교 평가하였다. TGT를 1초로 설정하고 내부적 움직임을 고려하여 선량분포를 획득했을 때 치료시간은 증가하였다. 그러나 TGT를 1초로 설정한 것은 내부적 움직임을 고려하지 않은 선량분포 즉, 치료 조사면 내에 장기의 움직임이 없을 때와 비슷한 선량분포를 얻을 수 있었다. 그리고 문턱 詰없이 내부 장기가 움직일 때와 비교해서 반음영 영역에 불필요한 선량을 줄일 수 있었다. 또한 치료시간을 줄이기 위해서 문턱 값을 1.4초로 설정했을 때가 1초로 설정했을 때보다 시간 비에 따른 선량분포에 대해 효과적인 결과를 얻지 못했다. 즉, 시간은 줄었지만 치료영역 밖에 많은 선량이 분포하였다. 임상적으로 TGT를 설정해서 방사선 치료를 하기 위해서는 수학적인 계산 방법에 의한 내부 장기의 움직임을 표현하는 것이 아니라 실측에 의해서 모든 환자의 외부 움직임과 내부 움직임을 측정해야 한다. 또한 내부와 외부 움직임의 상관관계를 분석해서 환자의 호흡주기에 따른 내부 장기의 움직임 중에 이상적인 위치에서 문책 값을 설정 후 방사선치료를 시행하면 정상조직은 낮은 선량이 분포하면서 치료성적이 향상될 것이라 예상된다. In this study, we investigated the effect of time gating threshold on the delivered dose at a organ with internal motion by respiration. Generally, the internal organs have minimum motion at exhalation during normal breathing. Therefore to compare the dose distribution time gating threshold, in this paper, was determined as the moving region of target during 1 sec at the initial position of exhalation. The irradiated fields were then delivered under three conditions; 1) non-moving target 2) existence of the moving target in the region of threshold (1sec), 3) existence of the moving target region out of threshold (1.4 sec, 2 sec). And each of conditions was described by the moving phantom system. It was compared with the dose distributions of three conditions using film dosimetry. Although the treatment time increased when the dose distributions was obtained by the internal motion to consider the TGT, it could be obtained more exact dose distribution than in the treatment field that didn't consider the internal motion. And it could be reduced the unnecessary dose at the penumbra region. When we set up 1.4 sec of threshold, to reduce the treatment time, it could not be obtained less effective dose distribution than 1 sec of threshold. Namely, although the treatment time reduce, the much dose was distributed out of the treatment region. Actually when it is treated the moving organ, it would rather measure internal motion and external motion of the moving organ than mathematical method. If it could be analyzed the correlation of the internal and external motion, the treatment scores would be improved.

냉각핀 형상에 따른 타이어 사이드월의 표면온도 저감 효과 예측에 관한 연구

박재현(Jae Hyen Park),정성필(Sung Pil Jung),정원선(Won Sun Chung),전철균(Chul Kyun Chun) 대한기계학회 2016 大韓機械學會論文集B Vol.40 No.4

타이어의 반복적 변형과 노면과의 마찰은 열발생을 야기하여 타이어의 온도를 상승시킨다. 이 온도 증가는 타이어 손상을 가져오는 요인이 될 수 있다. 이 같은 온도 상승을 억제하고자 타이어 측면에 냉각핀을 적용하고, 이에 따른 냉각 효과를 규명하는 것이 본 연구의 목적이다. 이를 위하여 8개의 냉각핀 형상이 검토 되었으며, 냉각핀 형상에 따른 사이드월 표면 온도 저감 효과를 수치해석적 분석을 통해 규명하였다. 또한 핀 후류에서의 와류에 의한 유동특성과 열전달특성을 비교하였다. The friction and deformation of a tire causes heat generation, which causes a temperature rise of the tire. This temperature rise can be a source of tire damage. The object of this study is to investigate the cooling effect of the application of a fin to the tire side to suppress the temperature rise. Eight different fin shapes were considered, and the sidewall surface temperature reduction owing to the cooling fin shape was numerically analyzed. In addition, the flow characteristics and heat transfer characteristics of the vortex of the pin rear were compared.

정위 체부 고정틀을 이용한 체부 방사선수술의 예비적 결과

안승도(Seung Do Ahn),이병용(Byong Yong Yi),최은경(Eun Kyung Choi),김종훈(Jong Hoo Kim),노영주(Young Ju Nho),신경환(Kyung Hwan Shin),김경주(Kyoung Ju Kim),정원균(Won Kyun Chung),장혜숙(Hyesook Chang) 대한방사선종양학회 2000 Radiation Oncology Journal Vol.18 No.4

목 적: 1990년대 이후 개발된 정위 체부 고정틀을 이용한 체부 정위방사선수술의 치료효과, 치료의 정확성과 후유증에 대해 후향적으로 알아보고자 하였다. 대상 및 방법: 1997년 12월부터 1999년 6월까지 간암 3명, 동정맥기형 1명, 폐전이 6명와 간전이 1명 등 모두 11명에서 정위 체부 고정틀을 이용하여 체부 방사선수술을 시행했다. 환자의 고정은 정위 체부 고정틀에 vacuum pillow를 이용하여 수행하였고 chest marker와 leg marker를 이용하여 흉골부위 또는 등부위와 경골부위의 피부에 환자 위치 표시를 하였다. 이후 모의치료실로 이동하여 X선 투시기를 통해 횡경막의 움직임을 측정한 후 Diaphragm control을 사용하여 1 cm 이하로 횡경막의 움직임을 최소화하였다. CT-simulator를 이용하여 치료부위의 단층촬영을 시행한 후 치료계획을 세웠다. 매회 치료전 CT-simulator를 이용하여 단층촬영을 반복하여 최초의 단층촬영의 영상과 수동적으로 비교하여 치료의 정확성을 확인하고 오차가 5 mm 이내인 경우 치료를 시행하였다. 방사선 치료는 90% 등선량곡선에 10 Gy씩 1일 내지 2일 간격으로 3회 시행하여 총 30 Gy를 조사하였다. 결 과:중앙 추적관찰기간은 12개월이었다. 11명의 환자 중 1명(9%)의 환자에서 국소적 완전관해를 보였고 4명(36%)에서 부분관해를 보였다. 계획용표적체적은 3∼111 cc 였고 평균값은 18.4 cc 였다. 치료 오차를 측정한 결과 X, Y, Z 축으로 오차범위는 모두 5 mm 이내를 보였다. 치료 중 또는 치료 직후에 올 수 있는 고열, 통증 등의 급성후유증은 관찰되지 않았다. 결 론:정위 체부 고정틀을 이용한 체부 방사선수술은 뛰어난 치료의 재현성을 보여주었고 간 혹은 폐종양에서 유용한 치료 방법으로 이용될 수 있을 것으로 기대된다. Purpose :To evaluate efficacy and complication of stereotactic radiosurgery using stereotactic body frame. Methods and Materials : From December 1997 to June 1999, 11 patients with prima ry and metastatic tumors were treated with stereotactic radiosurgery using stereotactic body frame(Precision Therapy™ ). Three patients were treated with primary hepatoma and seven with metastatic tumor from liver, lung, breast, trachea and one with a rteriovenous malformation on neck. We used vacuum pillow for immobilization and made skin marker on sternum and tibia area with chest marker and leg marker. Diaphragm control was used for reducing movement by respiration. CT- simulation and treatment planning were performed. Set- up error was checked by CT- Simulator before each treatment. Dose were calculated on the 80∼90% isodose of isocenter dose and given consecutive 3 fractions for total dose of 30 Gy (10 Gy/fraction). Results :Median follow- up was 12 months. One patient (9%) showed complete response and four patients (36%) showed partial response and others showed stable disease. Planning target volumes (PTV) ranged from 3 to 111 cc (mean 18.4 cc). Set- up error was within 5 mm in all directions (X, Y, Z axis). There was no complication in all patients. Conclusion : In primary and metastatic tumors, stereotactic radiosurgery using stereotactic body frame is very safe, accurate and effective treatment modality.

^152Sm에서의 다중극 혼합비에 관한 연구

정원모,주관식,황한렬,정원균 연세대학교 자연과학연구소 1986 學術論文集 Vol.17 No.-

동일한 선원에 대한 감마-감마, 감마-내부전환전자 각상관관계 실험을 통하여 변형핵인 ^152Sm의 혼합비(δ)와 121.8keV전이의 내부 전환전자 입자매개변수(b_2)를 결정하였다. 감마선을 검출하는데는 두대의 Ge(Li)검출기를 내부전환전자를 검출하는 데는 표면장벽형검출기를 사용하였다. 실험을 통하여 다음과 같은 결과를 구하였다. 244.7 keV-121.8 keV ; δ =-0.012±0.007 688.6 keV-121.8 keV ; δ =17.4±3.01 964.0 keV-121.8 keV ; δ =9.51±1.93 1112.0 keV-121.8 keV ; δ =12.30±2.05 1408.0 keV-121.8 keV ; δ =0.16±0.07 964.0 keVγ-121.8 keVe_K ; b_2=1.66±0.26 1408.0 keVγ-121.8 keVe_K ; b_2=1.63±0.10 1408.0 keVγ-121.8 keVe_L ; b_2=0.99±0.13 혼합비는 PPQ(Pairing-Plus-Quadrupole)모델과 IBA(Interacting-Boson-Approximation)모델로부터 얻은 이론값과 비교하여 보았고 또한 입자매개변수값이 이론값과 큰 차이가 있는 것으로 보아 변형핵의 저에너지 E_2 전이에서 ‘anomaly’가 있는 것으로 추정된다. The mixing ratios (δ) and the internal conversion electron particle parameters (b_2) of the 121.8keV transition in deformed ^152Sm nuclei were determined by comparing the γ-γ and γ-e angular correlation measurements made with the same source. The experimental apparatus was constructed with a surface barrier detecter for electrons and two Ge(Li) detectors for gamma rays. The following results were obtained. 244.7 keV-121.8 keV ; δ =-0.012±0.007 688.6 keV-121.8 keV ; δ =17.4±3.01 964.0 keV-121.8 keV ; δ =9.51±1.93 1112.0 keV-121.8 keV ; δ =12.30±2.05 1408.0 keV-121.8 keV ; δ =0.16±0.07 964.0 keVγ-121.8 keVe_K ; b_2=1.66±0.26 1408.0 keVγ-121.8 keVe_K ; b_2=1.63±0.10 1408.0 keVγ-121.8 keVe_L ; b_2=0.99±0.13 The results are compared with the theoretical values derived from the Pairing-Plus-Quadrupole model and from the Interacting-Boson-Approximation model, and an 'anomaly' was found in the low-lying E_2 transition for deformed ^152Sm nuclei.

血管 造影劑의 腎毒性에 關한 臨床的 硏究

全惠廷,鄭元均,徐源赫 고려대학교 의과대학 1987 고려대 의대 잡지 Vol.24 No.1

There has been many complications after infusion of radiologic contrast materials. Acute renal failure has been also one of complications following use of iodinated radiographic contrast media. But, recent developments of contrast media have reduced to very low instance the renal insufficiency following angiography. The present study was performed to analysis prospectively the incidence of acute renal failure in 148 consecutive patients who had angiography. The angiographic studies were including 39 cases of celiac arteriography with superior mesenteric arteriography, 6 cases of cardiac angiography, 40 cases of cerebral arteriography, 42 cases of femoral arteriography and 21 cases of renal angiography. There were only two incidences of renal failure following the procedure. The contrast media were meglumine iothalamate 60%, sodium methylglucamine iothalamate 60%, sodium methylglucamine ioxitalamate 60%, sodium methylglucamine diatrizoate 76% and the dose was 1.1cc/㎏(CM/BW). We studied the levels of blood urea nitrogen, serum creatinine, prior to angiography, immediately after angiography, 24 hours and 48 hours after angiography respectively. The summarized results were as follows: 1. There was no significant change of blood urea nitrogen or serum creatinine level before and after angiography in 146 consecutive patients who were in normal renal function before angiography. But two patients who were pancreatic carcinoma and essential hypertension had been in renal insufficiency before angiography, showed renal failure after angiography. 2. There was no significant statistical difference between pre-angiography and post-angiography in the evaluation of BUN, serum creatinine in patients, regardless of age or kinds of contrast media. 3. Renal artery and non-renal artery injection such as cerebral, cardiac, celiac artery or severity of peripheral vascular disease did not have an effect on renal function.

모형을 이용한 CT상의 폐결절 크기계측에 관한 연구

김정혁,정원균,서원혁 고려대학교 의과대학 1987 고려대 의대 잡지 Vol.24 No.1

It has been well known that the role of computed tomography (CT) to evaluate pulmonary nodules, concerning CT attenuation values, size determination, and edge patterns. Although the assessment of the size of pulmonary nodules is not sufficiently accurate to distinguish benign from malignant lesions, the measurement of the real size of the lesion is still being stressed on CT examination. Many authors have indicated that solitary pulmonary nodules (SPNs), measured by 2.0㎝ or less in diameter, were more apt to be benign. And lung cancers which were less than 3.0 ㎝ in the greatest diameter have been considered T1 lesion on the base of TNM system (The American Joint Comitte for Cancer Staging), while tumors more than 3.0㎝ have already been T2 lesion. But as the CT is a synthetic image, the size of the lesion displayed on CT are greatly influenced by various factors. The author designed a chest and lung phantom with pulmonary nodules that enabled the accurate measurement of the size of SPNs on various window setting, and proposed the optimal window center (WC) for measurement of the real size on CT. The results were fellows: 1. As CT No. of SPNs increase on a fixed window center and width, an error of size also increase. 2. The measurement of size of SPNs are greatly influenced by window setting. 3. The size of SPNs is decreased, as the window center is increased, 4. It is not correspond with between the measured (WC) or real size and WC which is optimal for viewing. 5. The optimal WC for measurement of real sire is on -500HU and -400HU. 6. CT No. of wall of chest phantom with various amount of fat did not greatly influence size measurement of nodules.

혈관경의 구조 및 피판의 크기에 따른 도서형피판의 생존비율에 관한 비교연구

김우경,정원균,한승규 大韓成形外科學會 1995 Archives of Plastic Surgery Vol.22 No.5

A lot of reconstructive methods for soft tissue defects involving skin have been introduced, but there were some limitations in each method. Recently, there have been some reports of successful skin flaps that apparently depend on only arterial or venous blood flow. We performed this study to compare the survival rates of arterial and venous island flaps with those of conventional ones, the survival rates of arterial and venous island flaps each other, and the survival rates according to the flap size. On the groin area of the rats, skin flaps were elevated bilaterally based on inferior epigastric artery or vein. They were divided into three groups: group Ⅰ-flaps based on inferior epigastric artery : group Ⅱ-flaps based on inferior epigastric vein : group Ⅲ - flaps with inferior epigastric artery and vein. Each group included twenty four flaps and were subdivided into subgroup A(n=12) and subgroup B(n=12) according to flap size(subgroup A : 2×3cm, subgroup B : 1×1.5cm). Flap survival rates of each group were evaluated and compared. The results were as followings: 1. Survival rates of the arterial and venous island flaps were significantly lower than those of conventional island flaps regardless of flap size (P < 0.050). 2. In making a comparison between arterial and venous island flaps, survival rate of the venous island flaps was higher than that of arterial ones. Especially in large flaps the difference was statistically significant (P=0.019). 3. Survival rate of large flaps was lower than that of small ones, but statically not significant. All conventional flaps survived completely regardlessly of flap size.

服部腫塊(81例)의 血管造影에 關한 放射線學的 考察

金基廷,鄭元均 順天鄕病院 1976 順天鄕醫報 Vol.1 No.1

Aortography and selective visceral injections has veen recognized as highly diagnostic and rather easy technique for the enaluation of various abdominal and retroperitoneal mass lesions. The writers have collected and analized 81 cases, whose chief complaints were slowly growing abdominal mass lesion out of 250 cases of abdominal aortography recent several years. The angiographic study were comprehensively analized which were not well detected with conventional study, and obtained results are summarized as follows. 1) Out of 81 cases female predominated over the male was 43 to 38, and age of the patients ranged from 12 years to 66 years. 2) Above one-half of cases were rather slowly growing goose egg sized mass localized one side of flank. 3) About two-third of cases were renal expanding lesions which composed with 15 hypernephroma, 10 renal tuberculosis, 9 renal cyst, 8 hycronephrosis(excluding tbc.hydro), 3 Wilms'tumor and 2 ureteropapillomatous carcinoma involving renal pelvis. 4) Other retroperitoneal expanding lesion: 3 pheochromocytoma, 1 neuroblastoma, 1 teratoma, 1 myxoma, 1 metastasis from fibromymata uteri, 1 Hodgkin's sarcoma, 4 Cushing's syndrme, 3 abscess, 1 ureteral transitional cell carcinoma, 1 malignant lymphoma, 1 ovarian cyst, 1 tuberculous salpingitis and 1 multiple saccular abdominal aneurysm. 5) 14 cases of abdominal mass were detected which composed 5 liver, 6 pancreas, 3 spleen lesions. 6) Abdominal aortography and selective visceral injection gave more diagmostic than any other radiological examination in detecting abdominal and retroperitoneal lesions which could not be approched with other radiological examinations.