Projections of summertime ozone concentration over East Asia under multiple IPCC SRES emission scenarios

Lee, Jae-Bum,Cha, Jun-Seok,Hong, Sung-Chul,Choi, Jin-Young,Myoung, Ji-Su,Park, Rokjin J.,Woo, Jung-Hun,Ho, Changhoi,Han, Jin-Seok,Song, Chang-Keun Elsevier 2015 Atmospheric environment Vol.106 No.-

<P><B>Abstract</B></P> <P>We have developed the Integrated Climate and Air Quality Modeling System (ICAMS) through the one-way nesting of global–regional models to examine the changes in the surface ozone concentrations over East Asia under future climate scenarios. Model simulations have been conducted for the present period of 1996–2005 to evaluate the performance of ICAMS. The simulated surface ozone concentrations reproduced the observed monthly mean concentrations at sites in East Asia with high R<SUP>2</SUP> values (0.4–0.9), indicating a successful simulation to capture both spatial and temporal variability. We then performed several model simulations with the six IPCC SRES scenarios (A2, A1B, A1FI, A1T, B1, and B2) for the next three periods, 2016–2025 (the 2020s), 2046–2055 (the 2050s), and 2091–2100 (the 2090s). The model results show that the projected changes of the annual daily mean maximum eight-hour (DM8H) surface ozone concentrations in summertime for East Asia are in the range of 2–8 ppb, −3 to 8 ppb, and −7 to 9 ppb for the 2020s, the 2050s, and the 2090s, respectively, and are primarily determined based on the emission changes of NO<SUB>x</SUB> and NMVOC. The maximum increases in the annual DM8H surface ozone and high-ozone events occur in the 2020s for all scenarios except for A2, implying that the air quality over East Asia is likely to get worse in the near future period (the 2020s) than in the far future periods (the 2050s and the 2090s). The changes in the future environment based on IPCC SRES scenarios would also influence the change in the occurrences of high-concentrations events more greatly than that of the annual DM8H surface ozone concentrations. Sensitivity simulations show that the emissions increase is the key factor in determining future regional surface ozone concentrations in the case of a developing country, China, whereas a developed country, Japan would be influenced more greatly by effects of the regional climate change than the increase in emissions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Change in ozone level is determined by the combination of NO<SUB>x</SUB> and NMVOC emissions. </LI> <LI> Ozone level over East Asia would get worse in the near future (the 2020s) than far future. </LI> <LI> A high-concentration event generally increases and more frequently occurs in the future. </LI> <LI> Change in ozone air quality in a developing country depends more on emissions change. </LI> <LI> Change in ozone air quality in a developed country depends more on climate change. </LI> </UL> </P>

1990년대 강우석 영화의 서울 공간 재현

장우진(Chang, Woo Jin) 한국영화학회 2018 영화연구 Vol.0 No.75

이 글은 가장 대중적인 상업영화 감독으로 인정받는 강우석 감독의 1990년대 영화가 서울의 주거공간과 도시공간을 어떻게 재현하고 있는지 논의한다. 분석대상은 서울 올림픽 이후부터 IMF 사태 발생 전까지 제작된 〈행복은 성적순이 아니잖아요〉(1989), 〈나는 날마다 일어선다〉(1990), 〈누가 용의 발톱을 보았는가〉(1991), 〈미스터 맘마〉(1992), 〈투캅스〉(1993), 〈마누라 죽이기〉(1994), 〈투캅스2〉(1996)이며, 이들 작품은 모두 서울을 공간적 배경으로 한다는 공통점이 있다. 이 글이 제기하는 질문은 세 가지이다. 첫째, 1990년대 서울 공간 변화의 특징이 무엇인가? 둘째, 1990년대 강우석의 영화들은 서울의 주거공간과 도시공간을 어떻게 재현하고 있는가? 셋째, 그러한 주거공간과 도시공간의 영화적 재현을 통해 우리가 독해할 수 있는 당대의 가치체계나 욕망, 불안 등은 어떠한 것인가? 1990년대는 경제적 호황과 더불어 중산층이 급부상한 시기였다. 이 시기에 서울은 아파트 단지가 대규모로 개발되었고 교통망이 크게 확충되었다. 이에 따라 도시 분산화가 이루어졌고, 아파트는 서울 중산층의 대표적 주거공간이 되었다. 강우석의 영화는 1991년까지 주로 현실 비판의 영화였으며, 아파트를 부정적 이미지로 재현하였다. 그러나 1992년 이후 아파트는 중산층 인물의 평범하고도 일상적인 주거공간으로 제시되었다. 이는 당시 아파트가 중산층이 소유하기를 원하는 욕망의 대상이 된 현실을 반영한 것이며, 강우석의 영화는 현실과 동경의 어색한 부정교합 형태로 중산층의 욕망을 소비하게 만들었다. 또한, 당시 한국영화가 도시의 화려함에 주목한 반면, 강우석의 영화는 개발이 되지 않았거나 이미 버려진 도시의 주변공간을 주목하는 경향이 있었다. 이것은 발전의 미완을 상기시켜 주었다. 한편, 강우석의 영화는 새로운 도시공간으로서 자동차 실내공간을 제시하였다. 당시 중산층의 사적 욕망과 소비 대상이었던 자동차의 실내공간은 이제 개인의 자유와 프라이버시가 보장된 은밀한 사적 공간으로 재현되었다. This paper discusses how are the residential and urban spaces in Seoul represented in the 1990s movies directed by Kang Woo-suk who was recognized as the most popular commercial film director in Korea. The subjects of the analysis are as follows: 〈행복은 성적순이 아니잖아요〉(1989), 〈나는 날마다 일어선다〉(1990), 〈누가 용의 발톱을 보았는가〉(1991), 〈미스터 맘마〉(1992), 〈투캅스〉(1993), 〈마누라 죽이기〉(1994), 〈투캅스2〉(1996). All of these have a common thing that they have a spatial background in Seoul. There are three questions that this paper poses. First, what are the characteristics of spatial change in Seoul during the 1990s? Second, how did the films of Kang Woo-suk in the 1990s reproduce the residential and urban spaces in Seoul? Third, what are the value systems, desires, and anxieties of those days that we can read through the cinematic representation of residential spaces and urban spaces? The 1990s was a time when the middle class emerged with economic boom. At this time, apartment complexes were developed on a large scale in Seoul and the transportation network was greatly expanded. As a result, urban decentralization has been achieved, and the apartment has become a representative residential space of the middle class in Seoul. Kang Woo-suk ‘s movies were mainly films of criticism of reality until 1991, and they reproduced the apartments as negative images. However, since 1992, apartments have been presented as ordinary and everyday living spaces of middle class people in his movies. This reflects the fact that the apartment was the object of desire to be owned by the middle class at that time, and Kang Woo-suk’s movie made spectators consume the desire of the middle-class in the form of awkward malocclusion of reality and longing. In addition, while Korean films generally paid attention to the splendor of the city, Kang Woo-suk’s films tended to pay attention to the surrounding space of the city that had not been developed or had been abandoned. This reminded us of the incompleteness of development. On the other hand, Kang Woo-suk’s movies presented the interior space of a car as a new urban space. The interior space of a car, the target of private desires and consumptions of middle class, became represented as a private urban space with individual freedom and privacy guaranteed.

아세틸 콜린 유발 검사시 허혈성 심전도 변화와 흉통의 발생이 내피세포 기능장애에 미치는 영향

최철웅(Cheol Ung Choi),나승운(Seung-Woon Rha),김선원(Sun Won Kim),나진오(Jin Oh Na),임홍의(Hong Euy Lim),김진원(Jin Won Kim),김응주(Eung Ju Kim),한성우(Seong Woo Han),박창규(Chang Gyu Park),서홍석(Hong Seog Seo),오동주(Dong Joo Oh) 대한임상노인의학회 2010 대한임상노인의학회지 Vol.11 No.4

연구배경: 아세틸 콜린 유발 검사시 발생하는 흉통과 허혈성 심전도 변화가 아세틸 콜린에 의해 발생하는 관상동맥의 내피세포 기능에 어떤 영향을 주는지 알아보고자 했다. 방법: 흉통으로 내원하여 관상동맥 조영술과 아세틸 콜린 유발검사를 시행받은 1,085명의 환자를 대상으로 하였다. 아세틸 콜린 유발 검사를 하는 동안 허혈성 심전도 변화 및 흉통의 발생 유무에 따른 관상동맥 내피세포 기능의 특징을 비교하였다. 결과: 539명의 환자에서 아세틸 콜린 검사시 내피세포 기능 장애가 발생 하였다. 허혈성 심전도 변화가 있었던 그룹이 심전도 변화가 없었던 그룹보다 흉통이 더 많았고(78.1% vs. 60.8%, P=0.007), 관상동맥 조영술상 다발성 관상동맥 경련이 빈번하였고(59.4% vs. 40.6%, P=0.004), 관상동맥의 경련 정도도 더 심하였다(64.1% vs. 46.5%, P=0.006). 흉통이 있었던 그룹이 흉통이 없었던 그룹보다 허혈성 심전도 변화의 빈도가 더 높았다(14.7% vs. 7.5%, P=0.007). 또한 흉통이 있었던 그룹이 관상동맥 경련이 다발성으로 발생하는 경우가 많았고 (50.7% vs. 29.5%, P<0.001), 미만성으로 발생하는 경우가 많았고(87.1% vs. 75%, P<0.001), 관상동맥의 경련의 정도도 더 심하였다(51.6% vs. 43.5%, P=0.041). 결론: 아세틸 콜린 유발검사시 발생하는 허혈성 심전도 변화와 흉통은 관상동맥 경련의 정도와 경련이 발생하는 관상동맥 개수와 연관이 있다. Background: ECG changes and chest pain during acetylcholine (Ach) provocation tests may constitute important clinical parameters for Ach-induced endothelial dysfunction. We investigated the association between ischemic ECG changes and chest pain during the Ach-provocation test and angiographic characteristics of Ach-induced endothelial dysfunction. Methods: A total of 1,085 patients with anginal symptoms underwent diagnostic coronary angiography (CAG) and Ach-provocation tests. We compared angiographic characteristics of Ach-induced endothelial dysfunction according to the presence of ECG change and chest pain. Results: A total of 539 patients experienced Ach-induced endothelial dysfunction. Patients who experienced ECG change group suffered more frequent chest pain (78.1% vs. 60.8%, P=0.007), angiographically more frequent multiple coronary artery spasm (59.4% vs. 40.6%, P=0.004), and more severe coronary artery spasm (64.1% vs. 46.5%, P=0.006) than patients without ECG change. However, there was no difference in the length of endothelial dysfunction between the groups. The incidence of ischemic ECG changes in patients with chest pain was higher than in patients without chest pain (14.7% vs. 7.5%, P=0.007). Patients who experienced chest pain more often experienced multiple (50.7% vs. 29.5%, P<0.001), diffuse (87.1% vs. 75%, P<0.001), and severe coronary artery spasm (51.6% vs. 43.5%, P=0.041) than patients without chest pain. Conclusion: Ischemic ECG changes and chest pain during the Ach-provocation test are associated with multi-vessel involvement and severe coronary artery spasm. Chest pain is associated with the length of endothelial dysfunction, but ischemic ECG change is not.

Carotenoids 식이와 알코올이 혈액학적 성분과 간조직에 미치는 영향에 관한 연구

조만희,김연선,이상한,우기민,장예진,김창세 순천향의학연구소 1999 Journal of Soonchunhyang Medical Science Vol.5 No.2

Alcohol is well known agent which can damage the human tissues such as liver via stimulating lipid peroxidation and storage, denaturation of macromolecules, and inhibiting protein metabolism. On the other hand, carotenoids in addition to vitamins A, C, E and lipoic acid, play important roles in protecting these oxidative damages as well as preventing the production of free radicals. This study was carried out to elucidate the precise effects of alcohol administration into rats on the antioxidative functions of dietary carotenoids and isolated β-carotene, and to find out any parameters to uncover more detailed biochemical mechanisms of these agents. For these purposes, two different approaches were performed: 1) examination of the changes in hematological parameters (e.g., total proteins, A/G ratio, ALT/AST et. al) and statistical correlations among inter- and intragroups, 2) examination of the histopathological changes by an electron microscope. The results were analyzed and summarized as following; (1) Carrot diet for one week caused a slight increase in albumin. A/G ratio and AST levels, and a slight decrease in ALT, ALP, BUN and uric acid levels. Two-week alcohol administration following carrot diet increased total proteins, albumin A/G ratio and BUN levels. However, both groups were shown to have little significant changes in cholesterol concentrations. (2) Cheese diet for one week caused a significant increase in total proteins, albumin, AST, ALP, uric acid and total cholesterol levels, and a significant decrease in A/G ratio and glucose concentrations. However, two-week β-carotene diet following cheese intake increased total proteins albumin, A/G ratio, BUN and total cholesterol levels, whereas AST, ALT, ALP and uric acid levels were decreased. (3) Alcohol administration for one week caused an increase in AST activities and a decrease in total proteins, albumin, ALT, ALP and BUN levels. A successive β-carotene diet following alcohol administration increased total proteins, albumin, ALT, ALP and BUN levels, whereas decreased AST and uric acid levels. However, there were not significant changes in A/G ratio, glucose and total cholesterol levels in both groups. (4) β-carotene diet for one week caused a slight increase in albumin, glucose, AST and uric acid levels, and a slight decrease in ALP and BUN levels. Two-weeks alcohol administration following β-carotene diet increased albumin, glucose, BUN and total cholesterol levels, whereas decreased AST, ALT, ALP and uric acid levels. (5) Although the pathological investigation on the liver did not reveal significant changes, cheese diet group (CH-BC/1-CH) was shown to have some lipid deposits. Some results were unexpected and different from typical hematological changes shown by other researchers. Nonetheless, these results strongly suggest that the liver damage or hepatism caused by alcohol intake affects many kinds of biochemical metabolisms, which results in significant changes in many hematological parameters. In addition, dietary carotenoid and isolated β-carotene were shown to have protective roles against the biochemical changes by alcohol intake.

Safety and efficacy of dietary supplement (gintonin-enriched fraction from ginseng) in subjective memory impairment: A randomized placebo-controlled trial

Lee Woo-Jin,Shin Yong-Won,Chang Hyeyeon,Shin Hye-Rim,Kim Won-Woo,Jung Seok-Won,Kim Manho,Nah Seung-Yeol 한국한의학연구원 2022 Integrative Medicine Research Vol.11 No.1

Background: Gintonin inhibits β-amyloid production, increases acetylcholine level in the brain, and promotes neurogenesis. We evaluated the efficacy of gintonin-enriched fraction (GEF) in improving the cognitive performance in subjective memory impairment. Methods: In this 8-week, randomized, assessor and participant blinded, placebo–controlled study, participants with subjective memory impairment but preserved cognitive function (Korean Mini-Mental State Examination [K-MMSE] score ≥23) were assigned to GEF 300mg/day or placebo. K-MMSE, Korean versions of the Alzheimer's disease assessment scale, color-word stroop test (K-CWST), clinical dementia rating, and Beck depression inventory-II were evaluated along with the safety profiles. The primary outcome was set as the change in the K-MMSE. Results: Seventy-six participants complete the study protocol. After 8 weeks, there was no inter-group difference in the primary or secondary outcome score changes. However, GEF group showed an improvement in the K-MMSE scores (P= 0.026), and in the number of correct answers in both word reading (P= 0.008) and color reading (P= 0.005) of K-CWST, although only the improvement in the K-CWST scores were higher than the minimum clinically important difference. The frequency of adverse events was comparable between the groups and all were of mild severity. Conclusion: GEF is safe but might not be effective in treating subjective memory impairment within the current study setting. However, GEF showed a trend of improving the global cognition and the frontal executive function. Further large-sized studies with longer follow-up period are warranted. Clinical trial registration: This clinical trial was registered at Clinical Research Information Service of Korea Centers for Disease Control and Prevention: KCT0004636. Background: Gintonin inhibits β-amyloid production, increases acetylcholine level in the brain, and promotes neurogenesis. We evaluated the efficacy of gintonin-enriched fraction (GEF) in improving the cognitive performance in subjective memory impairment. Methods: In this 8-week, randomized, assessor and participant blinded, placebo–controlled study, participants with subjective memory impairment but preserved cognitive function (Korean Mini-Mental State Examination [K-MMSE] score ≥23) were assigned to GEF 300mg/day or placebo. K-MMSE, Korean versions of the Alzheimer's disease assessment scale, color-word stroop test (K-CWST), clinical dementia rating, and Beck depression inventory-II were evaluated along with the safety profiles. The primary outcome was set as the change in the K-MMSE. Results: Seventy-six participants complete the study protocol. After 8 weeks, there was no inter-group difference in the primary or secondary outcome score changes. However, GEF group showed an improvement in the K-MMSE scores (P= 0.026), and in the number of correct answers in both word reading (P= 0.008) and color reading (P= 0.005) of K-CWST, although only the improvement in the K-CWST scores were higher than the minimum clinically important difference. The frequency of adverse events was comparable between the groups and all were of mild severity. Conclusion: GEF is safe but might not be effective in treating subjective memory impairment within the current study setting. However, GEF showed a trend of improving the global cognition and the frontal executive function. Further large-sized studies with longer follow-up period are warranted. Clinical trial registration: This clinical trial was registered at Clinical Research Information Service of Korea Centers for Disease Control and Prevention: KCT0004636.

Three-dimensional analysis of soft and hard tissue changes after mandibular setback surgery in skeletal Class III patients

Park, Jae-Woo,Kim, Nam-Kug,Kim, Myung-Jin,Chang, Young-Il The Korean Association Of Orthodontists 2005 대한치과교정학회지 Vol.35 No.4

하악 수술로 치료한 골격성 3급 부정교합 환자의 연조직 변화를 3차원적으로 분석하였다. 수술전과 수술후에 CT를 촬영하고, 연조직과 경조직을 각각의 임계값에 따라 segmentation였다. FH.평면, 정중시상면, PNS를 포함하는 전두면을 기준으로 공통 좌표계를 구성하고, 이 좌표계를 기준으로 술전, 술후 영상을 위치시켰다. 술후의 변화를 측정하기 위해 각각의 모형에 대해 전두면에 평행한 grid를 형성하였다. Grid내의 교점에서 골조직과 연조직 모형에 투사하여 만나는 점의 좌표값을 구하고, 이를 바탕으로 술후의 변화를 측정하였다. 하악골 후퇴술시 안모의 변화는 하악골 부분에서만 발생한 것이 아니라, 구각부에서도 관찰되었다. 하악골 부위의 연조직 변화는 대응되는 골조직 이동량에 따른 상대적인 값으로 계산하였다. 정중시상면에서의 변화율은 $77\~102\%$로 나타났다. (p<0.05). 정중시상면 이외의 부분의 변화양상도 이와 유사하였다. 구각부에서의 변화는 하악골의 이동을 대표할 수 있는 점의 이동량에 대한 상대적인 값으로 계산하였다. 정중시상면에서의 변화는 B점을 기준으로 $14\~29\%$이고, Pog점을 기준으로 $17\~37\%$, grid상 83번째 점을 기준으로 $11\~22\%$로 관찰되었다.(p<0.05) The three-dimensional (3D) changes of bone, soft tissue and the ratio of soft tissue to bony movement was investigated in 8 skeletal Class III patients treated by mandibular setback surgery. CT scans of each patient at pre- and post-operative states were taken. Each scan was segmented by a threshold value and registered to a universal three-dimensional coordinate system, consisting of an FH plane, a mid-sagittal plane, and a coronal plane defined by PNS. In the study, the grid parallel to the coronal plane was proposed for the comparison of the changes. The bone or soft tissue was intersected by the projected line from each point on the gird. The coordinate values of intersected point were measured and compared between the pre- and post-operative models. The facial surface changes after setback surgery occurred not only in the mandible, but also in the mouth corner region. The soft tissue changes of the mandibular area were measured relatively by the proportional ratios to the bone changes. The ratios at the mid-sagittal plane were $77\~102\%(p<0.05)$. The ratios at all other sagittal planes had similar patterns to the mid-sagittal plane, but with decreased values. And, the changes in the maxillary region were calculated as a ratio, relative to the movement of a point representing a mandibular movement. When B point was used as a representative point, the ratios were $14\~29\%$, and when Pog was used, the ratios were $17\~37\%(9<0.05)$. In case of the 83rd point of the grid, the ratios were $11\~22\%(p<0.05)$.

기후변화와 키메라현상에 대한 계층 간의 관계인식

백정애(Jungae Baik),김인경(In Kyoung Kim),김진영(Jin Yung Kim),노용환(Yong Hwan Noh),배선영(Sunyoung Bae),우명원(Myoung Won Woo),장혁기(Hyukki Chang),조성돈(Sung Don Cho),장매희(Maehee Chiang) 인간식물환경학회 2011 인간식물환경학회지 Vol.14 No.3

This study was investigated to research the basis of interdisciplinary fusion through the survey on the basis of the answers of professionals and general public, gender, humanities, science and engineering about the question of climate change and chimera which is one of the various phenomena that affect the human life. All respondents’ perceptions of climate change was high and natural disasters was showed the most destruction according to climate change. The answer of awareness of climate change and the damage, chimerism was significant differences between age groups sex, specialized domain-specific individuals. In addition, a group of respondents for science and engineering professionals was higher for awareness of climate change and the chimerism and heir negative opinion for chimerism was relatively low in comparison of other research groups.

Diagnostic Significance of Brainstem Auditory Evoked Potentials in Microvascular Decompression of Patients with Hemifacial Spasm or Trigeminal Neuralgia

( Sang-koo Park ),( Sung-hyuk Lim ),( Chan-woo Park ),( Jin-woo Park ),( Sung-ho Chang ),( Keun-hye Park ),( Hae-ja Park ),( Ji-hye Song ),( Dong-ok Uhm ),( Ki-bong Kim ) 대한임상검사과학회 2011 대한임상검사과학회지(KJCLS) Vol.43 No.1

The purpose of this study was to analyse brainstem auditory evoked potentials (BAEP) wave change data during microvascular decompression (MVD). The nerve function of Cranial Nerve VIII is at risk during MVD. Intraoperative monitoring of BAEP can be a useful tool to decrease the danger of hearing loss. Between January and December 2009, 242 patients had MVD for hemifacial spasm (HFS) and trigeminal neuralgia (TN). Among intraoperative BAEP changes, amplitude of V-V’ was the most frequently observed during cerebellar retraction and decompression step of the MVD procedure. 138 patients (57%) had no BAEP change while 104 patients (42.98%) had BAEP change. 69 patients (28.5%) had Type A-I, 16 patients (6.6%) had Type A-II, 5 patients (2.1%) had Type B, and 13 patients (5.37%) had Type C. MVD is a surgical procedure to relieve the symptoms (e.g. pain, muscle twitching) caused by compression of a nerve by an artery or vein. During BAEP intraoperative monitoring, the surgical step is important in interpreting the changes of wave V. Several potential mechanisms of injury may affect the cochlear nerve, and complete loss of BAEP is often associated with postoperative hearing loss. Intraoperative BAEP monitoring may provide an early warning of hearing disturbance after MVD.

Diagnostic Significance of Brainstem Auditory Evoked Potentials in Microvascular Decompression of Patients with Hemifacial Spasm or Trigeminal Neuralgia

Park, Sang-Koo,Lim, Sung-Hyuk,Park, Chan-Woo,Park, Jin-Woo,Chang, Sung-Ho,Park, Keun-Hye,Park, Hae-Ja,Song, Ji-Hye,Uhm, Dong-Ok,Kim, Ki-Bong 대한임상검사과학회 2011 대한임상검사과학회지(KJCLS) Vol.43 No.1

The purpose of this study was to analyse brainstem auditory evoked potentials (BAEP) wave change data during microvascular decompression (MVD). The nerve function of Cranial Nerve VIII is at risk during MVD. Intraoperative monitoring of BAEP can be a useful tool to decrease the danger of hearing loss. Between January and December 2009, 242 patients had MVD for hemifacial spasm (HFS) and trigeminal neuralgia (TN). Among intraoperative BAEP changes, amplitude of V-V' was the most frequently observed during cerebellar retraction and decompression step of the MVD procedure. 138 patients (57%) had no BAEP change while 104 patients (42.98%) had BAEP change. 69 patients (28.5%) had Type A-I, 16 patients (6.6%) had Type A-II, 5 patients (2.1%) had Type B, and 13 patients (5.37%) had Type C. MVD is a surgical procedure to relieve the symptoms (e.g. pain, muscle twitching) caused by compression of a nerve by an artery or vein. During BAEP intraoperative monitoring, the surgical step is important in interpreting the changes of wave V. Several potential mechanisms of injury may affect the cochlear nerve, and complete loss of BAEP is often associated with postoperative hearing loss. Intraoperative BAEP monitoring may provide an early warning of hearing disturbance after MVD.

PET/CT 검사 환자의 피폭선량 경감을 위한 연구

김봉수,표성재,조용귀,신채호,조진우,김창호,Kim, Bong-Su,Pyo, Sung-Jai,Cho, Yong-Gyi,Shin, Chai-Ho,Cho, Jin-Woo,Kim, Chang-Ho 대한핵의학기술학회 2009 핵의학 기술 Vol.13 No.3

목적 : 환자의 피폭선량 감소를 위해 PET/CT검사 시Pitch를 조절하여 환자의 피폭선량을 줄일 수 있는 방법에 대해 고려해 보고 Pitch 조정이 CT 영상과 PET의 SUV값에 영향을 주어 변화가 있는지를 살펴 보고자 한다. 방법 : Siemens사의 Biograph Positron Emission Tomography (PET) Scanner (CT 형식 : TRCT-240-130 (WCT-240-130)을 사용하였다. 환자의 피폭선량 평가로는 CT 조사선량 측정기인 PTW-DIADOS 11003/1383를 사용하여 선량을 측정하였고 Pitch 조정이 CT 영상에 미치는 영향을 알아보기 위해 AAPM Standard Phantom을 이용하여 pitch 변화에 따른 CT 영상의 공간 분해능을 측정하여 비교하였다. 그리고, PET source consists of a solid radioactive cylinder phantom을 사용하여 Pitch 변화에 따른 Fusion 영상의 SUV값을 산출하여 PET/CT 영상에서 SUV값이 변하였는지 확인하였다. 결과 : 2slice CT scanner에서는 Pitch가 0.7~1.3까지는 방사선량이 크게 떨어지나 1.5~1.9까지는 방사선량의 감소가 작아졌으며 Pitch값이 커질수록 환자의 피폭선량이 작아지는 것을 알 수 있었다. 그리고 Pitch값의 증가에 따른 SUV값의 변화는 거의 없었으며. Pitch값이 PET SUV값에 영향을 주지 않는다는 것을 알 수 있었다. Pitch의 변화가 CT 영상에도 크게 영향을 주지 않는 것을 알 수 있었다. 결론 : 위의 결과로 PET/CT를 사용하는 병원은 영상의 왜곡이 없고 PET SUV값에 영향을 주지 않는 범위 내에서 각 병원에 맞는 Pitch값을 찾아서 환자의 피폭 경감을 위해 노력해야 할 것이다. 그리고 Multi-detector를 가진 CT scanner인 경우에 모두 해당 될 것이라 생각되며 향후 다른 장비에서도 이와 같은 실험이 필요하다 하겠다. Purpose: As the number of patients has increased since the installation of a PET/CT, we are now examining about 2500-3000 annually. We have realized that if we properly adjust a pitch under the same condition of a CT during a PET/CT exam, radiation quantity that reaches the patient can change. In order to reduce the exposure dose of a patient, the research examines a method of reducing the exposure dose of a patient by controlling the pitch during a PET/CT exam, viewing whether the adjustment of the pitch influences CT image and PET SUV. Methods: The equipment used is a Biograph Positron Emission Tomography (PET) Scanner (CT type: TRCT-240-130 (WCT-240-130)) of Siemens company. For the evaluation of exposure dose of a patient, we measured radiation quantities using a PTW-DIADOS 11003/1383, which is a CT radiation measurement instrument used by Siemens. We measured and analyzed the space resolutions of CT images caused by the change of pitches using an AAPM Standard Phantom in order to see how the adjustment of pitches influenced the CT images. In addition, in order to obtain SUVs caused by each change of pitches using a PET source made with a solid radioactive cylinder phantom, we confirmed whether the SUVs changed in the PET/CT images by calculating the SUVs of the fusion images caused by the change of pitches after obtaining CT and PET images and finishing the test. Results: 2slice CT scanner showed that radiation quantities largely dropped when pitches ranged from 0.7 to 1.3 and that the reduction of radiation quantities were smaller when pitches ranged from 1.5 to 1.9. That is, we found that the bigger pitch values are the smaller the radiation quantities of a patient are. Moreover, we realized that there is no change of SUVs caused by the increase of pitches and that pitch values do not influence PET SUVs and the quality of CT images. It is judged that using 1.5 as a pitch value contributes to the reduction of exposure dose of a patient as long as there is no problem in the quality of an image. Conclusions: When seeing the result of the research, hospital using a PET/CT should make an effort to reduce the exposure dose of a patient seeking pitch values appropriate for their hospital within the range in which there is no image distortion and PET SUVs are not influenced from pitches. We think that the research can apply to all multi-detectors having a CT scanner and that such a research will be needed for other equipments in the future.