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      • KCI등재

        Evaluation and Comparison of Signal to Noise Ratio According to Change of Kernel size of Heart Shadow on Chest Image

        Yongkeun Song,Seunguk Heo,Gyuseok Cho,Sanghyun Choi,Moojae Han,Jikoon Park 한국방사선학회 2017 한국방사선학회 논문지 Vol.11 No.6

        꿈의 암치료기라고 불리는 중입자 치료는 환자의 암세포에 입사하여 암세포만을 사멸하고 사라지는데 이때 중성자 및 감마선이 발생되어 치료실 내 영상장비, 그 밖의 전자장비에 영향을 미치게 된다. 중입자 치료시설을 구축하기 위해서는 약 2,000억 원 가량의 예산이 필요하며 구축기간도 5년 이상 소요된다. 따 라서 구축 전 몬테카를로 시뮬레이션을 이용하여 치료실 내 선량 분포에 대해 관찰하여 적절한 대비를 하 는 것이 중요하다. 본 연구에서는 몬테카를로 시뮬레이션 툴인 FLUKA를 이용하여 중입자 치료 시 치료실 내 선량분포에 대해 알아보았으며 1분 치료 시 치료실 내에는 약 0.1 mSv에서 2 pSv 정도의 영향이 있을 것으로 파악되었다. The purpose of this study was to comparison of measure signal to noise ratio (SNR) according to change of kernel size from region of interest (ROI) of heart shadow in chest image. We examined images of chest image of 100 patients in a University-affiliated hospital, Seoul, Korea. Chest images of each patient were calculated by using ImageJ. We have analysis socio-demographical variables, SNR according to images, 95% confidence according to SNR of difference in a mean of SNR. Differences of SNR among change of equalization were tested by SPSS Statistics21 ANOVA test for there was statistical significance 95%(p<0.05). In SNR results, with the quality of distributions in the order of kernel size 9*9 image, kernel size 7*7 image and original chest image, kernel size 3*3 image (p<0.001). In conclusion, this study would be that quantitative evaluation of heart shadow on chest image can be used as an adjunct to the kernel size chest image.

      • KCI등재

        A Comparison Study of the Ridge Filter Parameter by Using FLUKA and GEANT4 Simulation Codes

        Yongkeun Song,Jaeik Shin,Sungho Cho,Seunghoon Yoo,Ilsung Cho,Eunho Kim,Wongyun Jung,Sanghyoun Choi,오경민 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.1

        We investigated the parameter optimization of the ridge filter’s thickness for carbon-ion therapy by using a Monte Carlo simulation. For this study, a ridge filter was designed for the spreadout Bragg peak (SOBP) by considering the relative biological effectiveness (RBE). The thickness, height, and width of the ridge filter were designed by using the FLUKA and the GEANT4 codes, and we analyzed and compared the results of the physical dose distributions for the FLUKA and the GEANT4 codes. The results showed that the minimum width of the groove for the ridge filter should be at least 0.5 cm for an appropriate biological dose. The SOBP sections were 8 cm, 9 cm, and 10 cm, respectively, when the heights were 3.5 cm, 4.0 cm, and 4.5 cm. The height of the ridge filter was designed to be associated with the SOBP width. Also, the results for the FLUKA and the GEANT4 codes showed that the average value of the difference was 3% and that the maximum error was 5%; however, the trends were similar. Therefore, the height and the width of the groove for the ridge filter are important parameters for deciding the length and the plateau of the SOBP.

      • 전산모사를 이용항 탄소빔 확장 브래그 피크 연구

        송용근(Song yongkeun),조성호(Cho sungho),정원균(Jung wongyun) 한국방사선학회 2014 한국방사선학회 학술대회 논문집 Vol.2014 No.추계

        탄소 빔을 환자의 치료를 위해 Spread out bragg peak (SOBP)로 변조하려면 Active 및 Passive 변조방식 등 두 가지 방법을 사용하고 있다. Active 변조 방식은 Bragg peak의 중첩으로 구현되고, Passive 변조 방식은 Ridge filter를 사용한다. Ridge filter 하나의 groove의 Height 및 Width는 SOBP의 형상을 결정한다. Ridge filter는 일반적으로 탄소치료 시설에서 사용되지만, 또한 양성자에도 사용된다. 현재 부산 기장군에 건설 중인 중비자치료시설은 Passive 변조 방식을 이용해서 SOBP를 구현 할 계획이다. Passive 변조방식의 주요 Component인 Ridge filter를 설계하기 위해, 전산모사를 수행하는 것이 필수적이다. 본 연구에서는 SOBP을 만드는 Ridge filter를 구현하고, FLUKA 2011코드를 사용하여 Water phatom 내 흡수되는 선량을 계산하였다. To create Spread Out Bragg Peak (SOBP) for the treatment of patient with carbon beam is two kinds of methods. There are active modulation and passive modulation, respectively. Active modulation method is implemented as superposition of Bragg Peak, and passive modulation method is using ridge filter. The ridge filter is a static component positioned in the beam line. The beam is spread to a monoenergetic, homogeneous field of carbon ions before entering the ridge filter. The shape of each of the groove determines the shape of the SOBP. Ridge filters are commonly used in carbon therapy facilities, but are also used for protons. At the carbon ion therapy center by Korea Institute of Radiological and Medical Sciences (KIRAMS) in Busan, Korea, we are planning to adopt the passive modulation. To design ridge filter of passive modulation key components, it is essential to carry out the Monte Carlo Simulation. In this study, we implemented ridge filter to create SOBP, and calculated absorbed dose in water phantom using FLUKA 2011 code.

      • KCI등재

        몬테카를로 시뮬레이션을 이용한 중입자 치료실의 선량분포 추정

        송용근(Yongkeun Song),허승욱(Seunguk Heo),조규석(Gyuseok Cho),최상현(Sanghyun Choi),한무재(Moojae Han),박지군(Jikoon Park) 한국방사선학회 2017 한국방사선학회 논문지 Vol.11 No.6

        꿈의 암치료기라고 불리는 중입자 치료는 환자의 암세포에 입사하여 암세포만을 사멸하고 사라지는데 이때 중성자 및 감마선이 발생되어 치료실 내 영상장비, 그 밖의 전자장비에 영향을 미치게 된다. 중입자 치료시설을 구축하기 위해서는 약 2,000억 원 가량의 예산이 필요하며 구축기간도 5년 이상 소요된다. 따라서 구축 전 몬테카를로 시뮬레이션을 이용하여 치료실 내 선량 분포에 대해 관찰하여 적절한 대비를 하는 것이 중요하다. 본 연구에서는 몬테카를로 시뮬레이션 툴인 FLUKA를 이용하여 중입자 치료 시 치료실내 선량분포에 대해 알아보았으며 1분 치료 시 치료실 내에는 약 0.1 mSv에서 2 pSv 정도의 영향이 있을 것으로 파악되었다. Heavy ion therapy has a high cure rate for cancer cell. So many countries are introducing heavy ion therapy facility. When treating a cancer using heavy ion therapy, neutrons and gamma rays are generated and affect electronic equipment. A budget of about KRW 200 billion is needed to build a heavy ion therapy facility, and it takes more than five years to build it. Therefore it is important to observe the dose distribution in the treatment room using the monte carlo simulation before construction. In this study, we used the FLUKA of monte carlo simulation to investigate the dose distribution in the heavy ion treatment room.

      • KCI등재

        Cardiovascular beriberi: rare cause of reversible pulmonary hypertension

        Song, Joon Hyuk,Cheon, Sang Soo,Bae, Myung Hwan,Lee, Jang Hoon,Yang, Dong Heon,Park, Hun Sik,Cho, Yongkeun,Chae, Shung Chull Yeungnam University College of Medicine 2014 Yeungnam University Journal of Medicine Vol.31 No.1

        Cardiovascular beriberi is caused by thiamine deficiency and usually presents as high cardiac output failure associated with predominantly right-sided heart failure and rapid recovery after treatment with thiamine. Because of its rarity in developed countries, the diagnosis can often be delayed and missed. We recently experienced a case of cardiovascular beriberi with pulmonary hypertension which successfully treated with thiamine infusion. A 50-year-old man with chronic heavy alcoholics was refered to our department for dyspnea with mental change. Echocardiography showed marked right ventricular (RV) dilatation and flattening of the interventricular septum with a D-shaped deformation of the left ventricle. Moderate tricuspid valve regurgitation was found and estimated RV systolic pressure was 52 mm Hg. Because of his confused mentality and history of chronic alcohol intake, neurological disorder due to thiamine deficiency was suspected and intravenous thiamine was administered and he continuously received a daily dose of 100 mg of thiamine. Follow up echocardiography showed marked reduction of RV dilatation and improvement of a D-shaped deformation of the left ventricle. He finally diagnosed as cardiovascular beriberi on the basis of dramatic response to intravenous thiamine. Thiamine deficiency can cause reversible pulmonary hypertension, and can still be encountered in the clinical setting. Thus high index of suspicion is critically needed for diagnosis.

      • KCI등재

        Cardiovascular beriberi: rare cause of reversible pulmonary hypertension

        Joon Hyuk Song,Sang Soo Cheon,Myung Hwan Bae,Jang Hoon Lee,Dong Heon Yang,Hun Sik Park,Yongkeun Cho,Shung Chull Chae 영남대학교 의과대학 2014 Yeungnam University Journal of Medicine Vol.31 No.1

        Cardiovascular beriberi is caused by thiamine deficiency and usually presents as high cardiac output failure associated with predominantly right-sided heart failure and rapid recovery after treatment with thiamine. Because of its rarity in developed countries, the diagnosis can often be delayed and missed. We recently experienced a case of cardiovascular beriberi with pulmonary hypertension which successfully treated with thiamine infusion. A 50-year-old man with chronic heavy alcoholics was refered to our department for dyspnea with mental change. Echocardiography showed marked right ventricular (RV) dilatation and flattening of the interventricular septum with a D-shaped deformation of the left ventricle. Moderate tricuspid valve regurgitation was found and estimated RV systolic pressure was 52 mm Hg. Because of his confused mentality and history of chronic alcohol intake, neurological disorder due to thiamine deficiency was suspected and intravenous thiamine was administered and he continuously received a daily dose of 100 mg of thiamine. Follow up echocardiography showed marked reduction of RV dilatation and improvement of a D-shaped deformation of the left ventricle. He finally diagnosed as cardiovascular beriberi on the basis of dramatic response to intravenous thiamine. Thiamine deficiency can cause reversible pulmonary hypertension, and can still be encountered in the clinical setting. Thus high index of suspicion is critically needed for diagnosis.

      • KCI등재후보

        Value of surgical resection compared to transarterial chemoembolization in the treatment of hepatocellular carcinoma with portal vein tumor thrombus: A meta-analysis of hazard ratios from five observational studies

        Keera Kang,Sung Kyu Song,Chul-Woon Chung,Yongkeun Park 한국간담췌외과학회 2020 Annals of hepato-biliary-pancreatic surgery Vol.24 No.3

        Backgrounds/Aims: Although systemic therapy is recommended in advanced hepatocellular carcinoma (HCC), treatment options for advanced HCC with portal vein tumor thrombosis (PVTT) are debatable. Recent studies have recommended other treatments, such as surgical resection (SR) and transarterial chemoembolization (TACE). Therefore, we performed a meta-analysis of hazard ratio (HR) for overall survival (OS) between the two modalities using previous reports in order to compare the two treatment options. Methods: A systematic review was performed on previously reported data that compared the survival benefits of SR and TACE in patients with advanced HCC with PVTT. Thereafter, the meta-analysis was performed to determine the cumulative HR between the two different treatment groups. We used the HR and 95% CI directly from the original data, when available; however, if these data were unavailable, reconstruction was performed with the secondary data from the original Kaplan-Meier survival curve. Results: A total of seven studies were eligible; however, 2 were excluded from the meta-analysis. The remaining 5 studies that included 1422 patients (SR group=559, TACE group=863) were studied for the meta-analysis. The median OS was longer in the SR group (8.2-64 months in SR vs. 6.6-32 months in TACE), proving that SR offered survival benefits. Moreover, the HR for the OS in the TACE group was 1.64 (95% CI, 1.43-1.88) compared to SR group, depicting that TACE was a less favorable option compared to SR. Conclusions: There is evidence that SR may be a better viable option for advanced HCC with PVTT.

      • KCI등재

        Comparing efficacies of different treatment regimens in patients with hepatocellular carcinoma accompanied by portal vein tumor thrombus using network meta-analysis

        Seungji Lee,Sung Kyu Song,Byungje Bae,Yongkeun Park 대한외과학회 2022 Annals of Surgical Treatment and Research(ASRT) Vol.103 No.5

        Purpose: Although various treatment regimens have been introduced for hepatocellular carcinoma (HCC) accompanied by portal vein tumor thrombosis (PVTT), comprehensive and direct comparisons between them are limited. Thus, the purpose of this study was to perform a network meta-analysis (NMA) to compare the efficacies of different treatment regimens for HCC accompanied by PVTT. Methods: A systematic review was conducted to identify studies comparing 2 or more treatment regimens for HCC accompanied by PVTT without extrahepatic metastasis and reporting each overall survival (OS). Endpoints of this NMA were to hazard ratios with confidential intervals for OS and mean survival time difference of each treatment regimen comparison using a random-effects model. Each treatment regimen was then ranked using the P-score to assess the probability of the superiority of each one. Results: Eleven studies involving 1,623 patients that yielded 16 comparisons were identified and enrolled in this NMA. There were 12 different treatment regimens as comparators, including sorafenib therapy alone (reference treatment). The NMA suggested that the following 4 treatment regimens improved OS compared to sorafenib: surgical resection followed by portal vein chemotherapy (SR plus PVC), SR, radiofrequency ablation plus sorafenib, and transarterial chemoembolization combined with selective internal radiation therapy. SR plus PVC was ranked the best treatment regimen for OS (P-score, 93.9%). Conclusion: Comparative efficacy based on this NMA may help clinicians select treatment for HCC accompanied by PVTT. If amenable, aggressive locoregional treatment regimens such as SR plus PVC should be considered for HCC accompanied by PVTT.

      • KCI등재

        몬테카를로 시뮬레이션을 이용한 차폐 및 방사화 계산에서 기하학적 모델링의 차이에 따른 결과 연구

        허승욱(Seunguk Heo),송용근(Yongkeun Song),조규석(Gyuseok Cho),한무재(Moojae Han),박지군(Jikoon Park) 한국방사선학회 2017 한국방사선학회 논문지 Vol.11 No.6

        방사선의 치료효과 증대를 위해 최근에는 기존의 Photon치료를 대체한 중입자치료가 증가하고 있다. 중입자 치료는 기존 Photon치료 대비 높은 에너지와 거대한 시설로 인해 방사선안전성평가에 더욱 신경을 써야 한다. 이러한 방사선안전성평가는 주로 Monte Carlo simulation을 이용하여 차폐 및 방사화 평가를 수행 하는데, 가장 우선적으로 수행해야하는 것은 기하학적 모델링이다. 중입자 치료시설은 가속장치를 싱크로 트론을 사용하게 되는데 정확한 기하학적 모델링이 어려워 대부분 간략하게 모델링 한다. 본 연구는 싱크 로트론 가속장치의 구성요소 중에서 Dipole magnet을 간략화 한 것과 정밀하게 구현한 것이 방사선안전성 평가에 어떠한 영향을 미치는지 알아보았다. 결과에 의하면 간략하게 구현한 기하학적 모델이 정밀하게 구현된 기하학적 모델보다 과대평과 되는 결과를 얻었다. 따라서 방사선안전성 평가는 정밀한 기하하적 모델 링이 더욱 신뢰할 수 있는 결과를 얻는다고 판단된다. In order to increase the therapeutic effect of radiation, there has been an increase in the use of conventional photon therapy. The intensive care unit should pay more attention to the radiation safety evaluation due to the higher energy and the larger facility compared to the existing Photon treatment. These radiation safety evaluations are mainly performed by using Monte Carlo simulation, and the first thing to be done is geometric modeling. The Heavy-ion treatment facility uses synchrotron as the accelerating device, which is difficult to precisely model geometrically and is mostly modeled briefly. This study investigated the effect of simplification and precise implementation of Dipole magnet among the components of synchrotron acceleration device on the radiation safety evaluation. The results show that the simplified geometric model is overestimated with the precisely implemented geometric model. Therefore, it is considered that the radiological safety evaluation results in more reliable results of the precise geometric modeling.

      • KCI등재후보SCOPUS

        Is partial hepatectomy a curable treatment option for hepatocellular carcinoma accompanied by cirrhosis? A meta-analysis and cure model analysis

        Byungje Bae,Keera Kang,Sung Kyu Song,Chul-Woon Chung,Yongkeun Park 한국간담췌외과학회 2022 Annals of hepato-biliary-pancreatic surgery Vol.26 No.1

        Backgrounds/Aims: It is challenging to assess the efficacy of partial hepatectomy (PH) as a treatment option for patients with hepatocellular carcinoma (HCC) accompanied by cirrhosis. This study aimed to determine the cure fraction of PH for HCC accompanied by cirrhosis compared to that for HCC without cirrhosis. Methods: A systematic review was performed on outcomes of previous studies that compared recurrence-free survival (RFS) after PH in patients with HCC with or without cirrhosis. A meta-analysis was conducted to obtain the cumulative hazard ratio for two patient groups: cirrhosis and non-cirrhosis. Cure fractions after PH in both groups were determined using a cure model analysis. Results: A total of 18 studies were eligible for meta-analysis and 13 studies were selected for the cure model analysis. The cumulative hazard ratio for RFS of the cirrhosis group compared to that of the non-cirrhosis group was 1.66 (95% confidence interval [CI], 1.43–1.93). Survival data of 3,512 patients in both groups were reconstructed from survival curves of original articles for cure model analysis. The probability of being statistically cured after PH for HCC was 14.1% (95% CI, 10.6%–18.1%) in the cirrhosis group lower than that (32.5%) in the non-cirrhosis group (95% CI, 28.6%–36.4%). Conclusions: The prognosis after PH for HCC accompanied by cirrhosis is inferior to that for HCC without cirrhosis. However, a cure can be expected for one-seventh of patients with HCC accompanied by cirrhosis after PH.

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