Evaluation of Images Depending on an Attenuation Correction in a Brain PET/CT Scan

최은진,정문택,동경래,곽종길,Jiwon Choi,Jae-Kwang Ryu (사)한국방사선산업학회 2018 방사선산업학회지 Vol.12 No.4

A Hoffman 3D Brain Phantom was used to evaluate two PET/CT scanners, BIO_40 and D_690, according to the radiation dose of CT (low, medium and high) at a fixed kilo-voltage-peak (kVp) with the tube current (mA) varied in 17~20 stages (Bio_40 PET/CT scanner: the tube voltage was fixed to 120 kVp, the effective tube current (mAs) was increased from 33 mAs to 190 mAs in 10 mAs increments, D_690 PET/CT scanner: the tube voltage was fixed to 140 kVp, tube current (mA) was increased from 10 mAs to 200 mAs in 10 mAs increments). After obtaining the PET image, an attenuation correction was conducted based on the attenuation map, which led to an analysis of the difference in the image. First, the ratio of white to gray matter for each scanner was examined by comparing the coefficient of variation (CV) depending on the average ratio. In addition, a blind test was carried out to evaluate the image. According to the study results, the BIO_40 and D_690 scanners showed a <1% change in CV value due to the tube current conversion. The change in the coefficients of white and gray matter showed that the Z value was negative for both scanners, indicating that the coefficient of gray matter was higher than that of white matter. Moreover, no difference was observed when the images were compared in a blind test.

지리적 기원이 다른 Pseudomonas syringae pv. actinidiae 균주들의 표현형적 특성

최은진,이영선,김경희,고영진,정재성,Choi, Eun Jin,Lee, Young Sun,Kim, Gyoung Hee,Koh, Young Jin,Jung, Jae Sung 한국미생물학회 2014 미생물학회지 Vol.50 No.3

Pseudomonas syringae pv. actinidiae는 참다래 속(genus Actinidia) 식물에 궤양병을 일으키는 원인세균이다. 7개의 필수 유전자와 11개의 타입 III 효과기 유전자에 대한 다중염기서열 분석을 통해 전 세계 여러 곳에서 분리된 병원성 균주들은 세 그룹으로 나눌 수 있었고 각각 Psa1-Psa3 그룹으로 명명되었다. 본 연구에서는 3개의 Psa1, 3개의 Psa2 및 우리나라와 이탈리아에서 분리된 3개씩의 Psa3 균주 등 총 12 균주를 대상으로 그룹별 표현형을 비교하였다. 그 결과 모든 그룹의 균주가 $22^{\circ}C$ 이하에서 최대의 성장을 보였으며, Psa3 균주들은 $30^{\circ}C$ 이상의 온도에서 성장이 정지되었다. 또한 우리나라의 Psa3 균주의 지연기가 이탈리아 Psa3 균주 보다 긴 특징을 보였다. API 20NE 시험에서 Psa2 균주는 potassium gluconate, capric acid 및 trisodium citrate를 이용하지 못하는 점에서 Psa1과 Psa3 균주와 구별되었다. 다른 그룹과 달리 우리나라 Psa3 균주는 esculin을 가수분해할 수 있었다. API ZYM 시험에서는 Psa3에 속하는 균주들에서만 ${\beta}$-glucosidase 활성이 있는 것으로 나타났다. Psa 그룹에 따라 ampicillin, novobiocin 및 oleandomycin 등의 항생물질에 대한 민감성 양상이 서로 달랐다. Pseudomonas syringae pv. actinidiae is the causal agent of bacterial canker in kiwifruit (genus Actinidia). Multilocus sequence analysis of seven housekeeping and 11 type III effector genes differentiated the virulent P. syringae pv. actinidiae isolates worldwide into three groups designated as Psa1-Psa3. In this work, a total of 12 P. syringae pv. Actinidiae strains, including three Psa1, three Psa2, three Psa3 strains isolated from Korea and three Psa3 strains from Italy, were compared based on their phenotypic properties. Strains with different geographic origins had unique growth patterns as demonstrated by growth rate at several temperatures; all tested strains exhibited maximum growth at temperatures below $22^{\circ}C$, while the growth of Psa3 strains was completely inhibited above $30^{\circ}C$. Psa3 strains isolated from Korea had longer lag phases than the Psa3 strains from Italy. The Psa2 strains were different from Psa1 and Psa3 strains in the API 20NE test, in which the Psa2 strains could not utilize potassium gluconate, capric acid and trisodium citrate. Psa3 strains isolated from Korea could hydrolyze esculin. The API ZYM test showed that ${\beta}$-glucosidase activity was detected only from Psa3 strains. The strains belonging to the three Psa groups differed with regard to their susceptibility to ampicillin, novobiocin, and oleandomycin.

Study of the Kinetic Effects on Relativistic Unmagnetized Shocks using 3D PIC Simulations

최은진,민경욱,최청림,Choi, Eun Jin,Min, Kyoung W.,Choi, Cheongrim,Nishikawa, Ken-Ichi 한국천문학회 2012 天文學會報 Vol.37 No.2

Shocks are ubiquitous in astrophysical plasmas: bow shocks are formed by the interaction of solar wind with planetary magnetic fields, and supernova explosions and jets produce shocks in interstellar and intergalactic spaces. The global morphologies of these shocks are usually described by a set of magnetohydrodynamic (MHD) equations which tacitly assumes local thermal equilibrium, and the resulting Rankine-Hugoniot shock jump conditions are applied to obtain the relationship between the upstream and downstream physical quantities. While thermal equilibrium can be achieved easily in collisional fluids, it is generally believed that collisions are infrequent in astrophysical settings. In fact, shock widths are much smaller than collisional mean free paths and a variety of kinetic phenomena are seen at the shock fronts according to in situ observations of planetary shocks. Hence, both the MHD and kinetic equations have been adopted in theoretical and numerical studies to describe different aspects of the physical phenomena associated with astrophysical shocks. In this paper, we present the results of 3D relativistic particle-in-cell (PIC) simulations for ion-electron plasmas, with focus on the shock structures: when a jet propagates into an unmagnetized ambient plasma, a shock forms in the nonlinear stage of the Weibel instability. As the shock shows the structures that resemble those predicted in MHD systems, we compare the results with those predicted in the MHD shocks. We also discuss the thermalization processes of the upstream flows based on the time evolutions of the phase space and the velocity distribution, as well as the wave spectra analyses.

Evaluation of the Dependence of the Exposure Dose on the Attenuation Correction in Brain PET/CT Scans Using 18F-FDG

최은진,정문택,장성주,최남길,한재복,양남희,동경래,정운관,Yun-Jong Lee,류영환,Sung-Hyun Choi,Kyeong-Jeong Seong 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.1

This study examined whether scanning could be performed with minimum dose and minimumexposure to the patient after an attenuation correction. A Hoffman 3D Brain Phantom was used inBIO 40 and D 690 PET/CT scanners, and the CT dose for the equipment was classified as a low dose(minimum dose), medium dose (general dose for scanning) and high dose (dose with use of contrastmedium) before obtaining the image at a fixed kilo-voltage-peak (kVp) and milliampere (mA) thatwere adjusted gradually in 17 - 20 stages. A PET image was then obtained to perform an attenuationcorrection based on an attenuation map before analyzing the dose difference. Depending on tubecurrent in the range of 33-190 milliampere-second (mAs) when BIO 40 was used, a significantdifference in the effective dose was observed between the minimum and the maximum mAs (p <0.05). According to a Scheffe post-hoc test, the ratio of the minimum to the maximum of theeffective dose was increased by approximately 5.26-fold. Depending on the change in the tubecurrent in the range of 10-200 mA when D 690 was used, a significant difference in the effectivedose was observed between the minimum and the maximum of mA (p < 0.05). The Scheffe posthoctest revealed a 20.5-fold difference. In conclusion, because effective exposure dose increaseswith increasing operating current, it is possible to reduce the exposure limit in a brain scan can be reduced if the CT dose can be minimized for a transmission scan.

Two cases of postoperative chylothorax treated with parenteral octreotide and conservative therapy

최은진,이섭,Choi, Eun Jin,Lee, Sub The Korean Pediatric Society 2007 Clinical and Experimental Pediatrics (CEP) Vol.50 No.3

Chylothorax is a rare complication following cardiac surgery for congenital heart diseases. Although conservative management is successful in the majority of cases, surgical intervention is required in a refractory one. Recently, subcutaneous or intravenous infusion of octreotide has been used as a safe treatment that helps avoiding surgical intervention. Herein, we report two cases of postoperative chylothorax treated with parenteral octreotide and conservative therapy. 선천성 심장병의 수술후 발생되는 유미흉은 드문 합병증이다. 이는 수분, 전해질 및 영양의 불균형을 초래할 뿐만 아니라 감염에 취약함을 보이기도 한다. 지금까지의 보존요법에 대해 비교적 치료성적이 좋으나 치료에 반응하지 않는 경우에는 수술적 중재가 불가피하다. 저자들은 보존요법과 octreotide 주입을 병행하여 수술적 중재를 피하고 효과적으로 치료한 수술후 발생된 유미흉 2례를 보고하는 바이다.

연수기 - 일본 성마리아 병원 연수기(1차)

최은진,Choi, Eun-Jin 한국가톨릭의료협회 2003 한국가톨릭병원협회지 Vol.33 No.-

중국의 ‘푸쓰녠傅斯年’연구의 지적 네트워크와 그 함의

최은진 ( Choi Eun-jin ) 수선사학회 2017 史林 Vol.0 No.62

In this paper, I applied the WNET metric analysis program to visualize the intellectual structure and network of the FuSinian study and analyze its implications. Since the major researchers group were highly productive as well as influential within the researchers, the data were extracted from the researches of the major researchers. As the main keywords, I paid attention to the structure and network of knowledge. As a result, I verified that Gu Jiegang顧?剛,1893-1980) and Chen Yinke (陳寅恪,1890-1969) showed the highest TBC, and the main researches on Fu which were focused on his thought of historiography and his scholarly works were being closely linked. Whereas researches related to FuSinian were generally focused on the relationship between FuSinian and other intellectuals in the period of ROC, but not on his political activities or classics studies. Secondly, keyword, Liu Yizheng(柳?徵) showed the highest NNC, and formed an important structure in FuSs-nien study. When I analyzed the extracted data in terms of the relationship between the authors, ⑦ group's Luo Zhitian(羅志田Sichuan四川 University History Department) showed the highest TBC, and Sang Bing(桑兵) was the most influential within the main research group, While Luo Zhitian reviewed FuSinian from the perspective of ideological history, Sang Bing concentrated on FuSinian’s works from the historiography of modern history. Both of them took FuSinian’s anti-traditional tendency into consideration, but, at the same time they tried to appreciate FuSinian’s cultural awareness or his patriotism though Fu insisted on anti-traditional changes through the Westernized method. These nationalistic studies were connected with the interest in Fu’s activities in History of the Northeast(東北史綱) and National People's Congress(國民參政會) as well as in his activities during the anti-Japanese period. However, researches on his “Scientism” were not the mainstream study except for the researches on the relevance with the Quellenkunde school. Additionally, the study by ZhangQing(章淸) which revealed the liberal aspect of FuSinian through his journal activities, despite the highest frequency of quotations was not related to mainstream research group.

논문(論文) : 남경국민정부시기 지방자치와 교육: 절강성(浙江省) 난계자치실험현(蘭溪自治實驗縣)의 사례를 중심으로

최은진 ( Eun Jin Choi ) 이화사학연구소 2015 梨花史學硏究 Vol.0 No.51

The background in which Lanxi county was selected as experimental Prefecture was related to the political purpose that Chiang Kai-shek and CC wave and the Kuomintang government were trying to seize the political initiative and to take control of the base layer of the regime in the unstable unified nation. In order to justify and rationalize the attempt of expanding influence of the government and ruling party in the base layer, it was inevitable to put forward that the proliferation of the education based on Three Principles of the People for the realization of local autonomy was the legacy of the Sun Yat-sen In Lanxi experiments, the local government enforced resolute plans to promote systematization and proliferation of the Three Principles of the People education and achieved the conversion of outdated pre-modern life style and the sweeping change in local leading forces. Specifically, in order to strengthen central government’s educational policy. the head of education department proceeded schemes to construct primary schools(Central Primary School, ranked private primary school, county-administered private class)from top to bottom, from the center to periphery. In addition, primary schools, especially central primary schools were designated as centers in charge of public educations, various athletic and Health Conference, PTA meetings aiming at modernization of Lanxi community. Thus, primary school in Lanxi County was functioned as a base to drive the social changes in the period of Nanjing national government. The strengthening of military training and national education, the core part of the Three Principles of the People education, was carried out by the Scouts organization under the request of Kuomintang which also indicated strongly that the nature of movement was top-down. From the educational experiments in Lanxi autonomy experiment County, it could be construed the educational activities acted as a mechanism to remove existing local autonomy flow in the region during the 1920s and to stabilize the government-led base layer regime even though they claimed to advocate local autonomy in the implementation process of centralized governance.

백스캐터 Wake-up Radio의 저전력 채널경쟁 및 고효율 데이터 전송

최은진(Eun-Jin Choi),김윤민(Yunmin Kim),이태진(Tae-jin Lee) 한국통신학회 2019 한국통신학회 학술대회논문집 Vol.2019 No.6

경남 방언의 비의도적 반어 표현

최은진 ( Eun Jin Choi ) 문창어문학회 2005 문창어문논집 Vol.42 No.-