위암의 역동적 자기공명영상: 조영증강 전 후 영상의 비교

홍성환,한준구,장기현,최병인 대한자기공명의과학회 1997 Investigative Magnetic Resonance Imaging Vol.1 No.1

목적: 역동적 자기공명영상에서 위암의 조영증강양상을 분석하여, 병변의 평가에 조영증강검사의 필요성을 규명하고자 하였다. 대상 및 방법: 병리조직학적으로 증명된 12명의 환자를 대상으로 하였다. 1.0T 자기공명영상장치를 이용하였고, FLASH T1 강조영상기법으로 조영제 주입전, 30초 후, 60초 후, 90초 후에 각각 횡단스캔을 얻었다. 검사 전 환자에게 1리터의 물을 마시게 하였고 장진경제인 Buscopan을 근육주사 하였다. 각 시기에서 병변의 신호 대 잡음비를 측정하였고, 병변과 췌장, 병변과 위장내 물과의 신호차이 대 잡음비를 측정하였다. 또한 각 시기의 영상에서 병변의 두으러짐을 0-3등급으로 나누어 두 명의 방사선과 의사가 합의하에 평가하였다. 결과: 병변의 신호 대 잡음비는 조영증강 전, 조영증강 후 30초, 60초, 90초의 시간경과에 따라 점차 증가하였다(38.7,42.5,57.4,65.7). 병변과 췌장과의 신호차이 대 잡음비는 10.5, 9.33, 9.99, 10.66으로 유의하게 증가하였다. 병변과 위장내 물과의 신호차이 대 잡음비도 1.24, 25.01, 39.30, 45.89로 유의하게 증가하였다. 그러나 정성적 분석에서는 조영 전 영상이 조영 후 영상에 비하여 병변의 두드러짐이 컸다(평균등급:2.8, 1.8, 1.6, 1.5). 병변의 신호강도는 조영증강 후 90초 지연영상에서 가장 높은 신호강도를 보여 병변의 위강쪽은 뚜렷하게 보였다. 그러나 병변과 위 주위 지방조직의 신호강도 차이가 줄어들어 전체적으로는 조영증강 전 영상에서 조영증강 후 영상보다 병변이 분명하게 보였다. 결론: 위암의 역동적 자기공명영상의 조영 전 영상에서 조영 후 영상보다 병변이 분명하게 보이므로 조영증강은 필요 없다고 생각된다. Purpose: To analyze contrast-enhancement pattern of stomach cancer on dynamic MRI and to verify the efficacy of intravenous contrast agent in the evaluation of stomach cancer. Materials and Methods: Twelve patients with proven stomach cancer underwent dynamic MRI. By using l.OT scanner, we obtained precontrast FLASH images, and 30, 60, 90 second delay FLASH images after intravenous contrast injection. All patients ingested one liter of water and had intramuscular injection of Buscopan just before MR study. For quantitative analysis we measured signal to noise ratio (SiN) of stomach cancer on each image, and signal difference to noise ratio (SD/N) between cancer and intraluminal fluid, cancer and the pancreas. For qualitative analysis two radiologists evaluated lesion conspicuity on each image by grading system(grade 0, 1, 2, 3: poor, fair, good, excellent). Results: SiN of stomach cancer increased gradually by time(precontrast, 30, 60, 90 second delay: 38.7, 42.5, 57.4, 65.7). SD/N between cancer and intraluminal fluid significantly increased after contrast enhancement(l.24, 25.01, 39.30, 45.89). SD/Ns between cancer and the pancreas were 10.5, 9.33, 9.99, 10.66, respectively. In qualitative analysis, precontrast images were better than postcontrast images for delineation of stomach cancer. Postcontrast images showed clear endo-Iuminal side of stomach cancer, but outer margin of stomach cancer was more distinct on precontrast images. Conclusion: Precontrast MR images are better than postcontrast MR images in the depiction of stomach cancer. Intravenous contrast agent is not imperative in the evaluation of stomach cancer.

영양실조의 지방경제

洪性煥 세계평화교수협의회 1985 廣場 Vol.142 No.-

1P-166 Graphene/alumina film stacked by layer-by-layer process with strongly anisotropic thermal conductivity and high specific heat

홍성환,유필진 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.0

도시 일차보건사업의 평가에 관한 실험적 연구

洪性換,廉容泰 고려대학교 의과대학 1991 고려대 의대 잡지 Vol.28 No.3

Recently. the urbanization rate of Korea reached up to 75% with the governmental effort of industrialization policy Accordingly, many of the poor in rural area moved into urban areas to make new slum in cities. It was inebitable for the slums to be medical1y underserved even the national insurance system would cover the whole country The insuranre capability did not include national health aspects such as disease prevention early detection of diseases. accessibillty of health care. and of others which remained as headache of the Government especially for the above urban slums. In light of above reasons. the Korea University performed a pilot health care service in Guro 6-dong in terms of urban primary health care services for 4 years from 1983 to 1986 with the grant from German Government. In this study. the authors evaluated the input and outcome of the project appling modern theories for evaluation. The results were as follows: 1. Evaluating the target area of the project. administrative1y it was composed of a total of 157 bans with 19 tongs. and a total of 14.164 inhabitants were living in 1.285 houses Comparatively. there were more of less educated and young adults of labourers who migrated from other cities or rural areas. 2 Input activities of public health nurse categorized into developmen of voluntary health resources. activation of existing health resourcrs.basic health services. health information collection. planning were calculated and evaluated. About 16% of working time for 4 years were spent for the abouve activities. For information collection and basic health services. the greatest amount of time were allocated. 3. In case of ancillary, there was no specific difference except the proportion of working time(17.7%) for 5 activities. 4. Analysing the enrollment of infant in wellbaby clinic of Guro Health Center in years of 1984 and 1986, increased performance rate attributable to service activity of target area was 44.7% and rate ratio of performance was 1.4. 5. Analysing the utilization frequency of family planning section of the Health Center in same way as above, increased performance rate attributable to service activity of target area was 17.4%, but rate ratio was incomparable becanse of negative increasement value of control area. 6. With the comparison results of the surveys on the antenatal care of pregnant women in 1982 and 1986 at target and control areas, it was revealed that increased performance(recognition of necessity) rate attributable to service activity of target area was 3.4% and rate ratio was 1.4 7. With the results of the above surveys, it was also revealed that increased performance rate of antenatal care attributable to service activity was 7.0% and rate ratio was 1.1. In short, the Korea University Urban P.H.C. services performed in Guro 6-dong from 1983 to 1986 was appraised to be positively valuable according to modern evaluation research methodologies. However, it can not be said that the project was performed efficiently and successfully because there was no comparative evaluation examples of the same methodology for similar urban PHC services at all in Korea.

Binder-free Heat Dissipation Films Assembled with Reduced Graphene Oxide and Alumina Nanoparticles for Simultaneous High In-plane and Cross-plane Thermal Conductivites

홍성환,유필진 한국고분자학회 2019 한국고분자학회 학술대회 연구논문 초록집 Vol.44 No.2

1P-175 Flexible Graphene/alumina paper with high in-plane and through-plane thermal conductivity

홍성환,유필진 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

Effective thermal management is becoming increasingly important for high-integrated electronics and miniaturized devices. Efficient heat dissipation reduces their operating temperatures and insures optimal performance and efficacy. Vertically and horizontally thermally conductive graphene/alumina papers were prepared by simple dropcasting of alumina and graphene solution. By controlling pH of graphene/alumina solution, specific structure that alumina particles were wrapped by graphene sheet was designed. As a result, without adding adhesive polymer, we successfully fabricated graphene/alumina papers having outstanding thermal properties for efficient accommodation and dissipation of heat from local heat source.

Gradationally Complexed Ag/TEMPO-oxidized Cellulose for Multifunctional Textiles

홍성환,유필진 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.1

Electrically conductive fibers play very important roles in realization of wearable technology due to their high flexibility and its various applications. In recent years, researches on the production of conductive fibers by various methods have been actively conducted. Particularly, various researches have been carried out to coat polymers on the fiber and to attach silver particles on polymer. However, when the polymer is coated on the fiber, there is a problem in that the electrical conductivity of the fiber is decreased because the silver particles and the polymer are separated by repeated bending. In order to solve these problems, we researched TEMPO-oxidation method and attaching silver nanoparticles directly to oxidized cellulose to fabricate conductive fiber. The conductive fibers produced by TEMPO-oxidation exhibit constant electrical conductivity and EMI shielding effectiveness.

Graphene/alumina films stacked by spin-assisted layer-by-layer process with high thermal conductivity and specific heat

홍성환,유필진 한국고분자학회 2018 한국고분자학회 학술대회 연구논문 초록집 Vol.43 No.1

Spin-assisted Layer-by-layer Assembly of Reduced Graphene Oxide Nanosheets and Alumina Nanoparticles for Heat-dissipation Films with High In-plane and Cross-plane Thermal Conductivity

홍성환,유필진 한국고분자학회 2018 한국고분자학회 학술대회 연구논문 초록집 Vol.43 No.2

토끼에 유발시킨 화농성 슬관절염: 자기공명영상과 병리소견의 비교연구

홍성환,고성혜,정혜원,이경원,김종재,강흥식 대한영상의학회 2002 대한영상의학회지 Vol.47 No.6

Purpose: To compare the MR imaging findings of experimentally induced pyogenic arthritis of rabbit knees with the corresponding histopathologic findings. Materials and Methods: Infection was induced in 20 rabbit knees by direct intra-articular injection of Staphylococcus aureus. The animals were divided into four groups of five rabbits each, and spin-echo sagittal T1-and T2-weighted images were obtained 3 days, 1 week, 2 weeks, and 4 weeks, respectively, after staphylococcal inoculation. MR-pathologic correlation was performed, with emphasis on intra-and extra-articular soft tissue lesion characteristics. Soft tissue lesion signal intensity (SI) was classified as low, iso, or high on the basis of that of muscle, and high SI was further subdivided into three categories. Results: At T2-weighted imaging, all soft tissue lesions showed high SI. Pathologic examination revealed the presence of inflammatory cell infiltration (n=2), abscess (n=1), granulation tissue (n=3), fibrosis (n=11), edema (n=4), congestion (n=9), and joint fluid (n=11). Except for the abscess, these lesions were irregular in shape and had variable SI (grade 1-3) and at T2WI could not, therefore, be differentiated. In nine kness, extraarticular soft-tissue lesions were demonstrated at T2WI and correlated with infectious soft tissue lesions such as inflammatory cell infiltration, abscess, granulation tissues and fibrosis; and non-infectious reactive soft tissue changes such as edema and congestion. Conclusion: In pyogenic arthritis, the MR imaging features of soft tissue lesions varied and were nonspecific, depending on the histopathologic abnormalities observed. Our results indicate that in assessing the extent of pyogenic arthritis with MR imaging, caution is required. 목적: 토끼 슬관절에 실험적으로 화농성 관절염을 유발시켜 이에 대한 자기공명영상 소견과 병리소견을 비교분석함으로써 자기공명영상 소견을 병리학적으로 규명하고자 하였다. 대상과 방법: 토끼 20마리의 우측 슬관절에 포도상구균을 직접 주입하는 방법으로 화농성 관절염을 만들었다. 20마리의 토끼를 5마리씩 4개의 군으로 나누어 각각 3일 후, 1주 후, 2주 후, 4주 후에 자기공명영상검사를 시행하였다. 자기공명영상은 스핀에코 T1강조 시상영상과 T2강조 시상영상을 얻었다. 자기공명영상 검사가 끝난 토끼를 희생시켜 조직처리하고 시상면으로 절단하여 병리표본을 제작하였다. 자기공명영상에서 나타난 관절 안쪽 및 바깥쪽 연부조직 병변을 병리소견과 비교하여 분석하였다. 병변의 신호강도는 근육과 같은 신호강도를 등신호강도, 그보다 낮은 경우 저신호강도, 그리고 근육보다 높은 경우를 고신호강도로 분류하었고, 고신호강도를 다시 3개의 등급으로 나누었다. 결과: T2강조영상에서 모든 병변은 고신호강도를 보였고 병리검사에서 염증세포침윤(2관절), 농양(1관절), 육아조직(3관절), 섬유화(11관절), 부종(4관절), 울혈(9관절) 및 관절삼출액(11관절)에 해당하였다. 농양을 제외하고는 모든 병변이 불규칙한 모양을 보였고, 고신호강도의 정도도 1-3등급으로 다양하여 각각의 병변을 자기공명영상 소견으로는 구별할 수 없었다. 자기공명영상에서 관절피막 바깥쪽에 병변을 형성한 경우는 9관절로, 병리검사에서 이들은 염증세포침윤, 농양, 육아조직, 섬유화 등의 감염성 병변과 부종, 울혈 등의 반응성 변화임을 확인하였다. 결론: 자기공명영상에서 화농성 관절염의 연부조직 병변은 그 종류에 따라 다양한 소견을 보여 비특이적인 양상을 나타냈다. 특히, 관절 바깥쪽으로 형성된 병변이 반드시 감염성 병변을 시사하는 것은 아니므로 병변의 범위를 평가할 때 주의를 요한다.