• Title/Summary/Keyword: Reduction methods

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Gender Difference of Accuracy in Detecting Coronary Artery Disease by Myocardial Perfusion SPECT (디피리다몰 심근관류 SPECT를 이용한 관동맥질환 진단에 있어 남녀간의 진단율 비교)

  • Min, Jung-Jun;Bom, Hee-Seung;Song, Ho-Cheon;Jeong, Hwan-Jeong;Kim, Ji-Yeul
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.2
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    • pp.129-136
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    • 1998
  • Purpose: Myocardial SPECT is an effective test for detecting coronary artery disease in the general population. But the diagnostic accuracy between sexes is not defined. The purpose of this study is to compare the diagnostic accuracy between males and females. Materials and Methods: One hundred and seventy seven male and 98 female patients who underwent myocardial SPECT within 1 month of coronary angiography were studied. Myocardial SPECTS were considered abnormal if fixed or reversible perfusion defects were detected. Stenosis severity of ${\geq}$ 50% luminal diameter reduction of any artery defined coronary artery disease (CAD). Results: Overall sensitivity for detection of CAD was 98% in men and 97% in women (p=not significant). However, specificities, accuracies, and positive predictive values (PPV) in men and women were 49% vs 31% (p<0.05), 81% vs 57% (p<0.01), 78% vs 48% (p<0.01), respectively. Diagnostic accuracies for detection of right coronary artery disease were not different in both sexes, however, accuracies for detection of left anterior descending artery disease and left circumflex artery disease were significantly lower in female (p<0.05). Conclusion: A significant difference of diagnostic accuracy between sexes, especially in LAD and LCx disease, was noted. Artifacts from breast attenuation might be a cause for the lower diagnostic accuracy in female.

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$^{99m}Tc$ Labeling Kit Preparation and Characteristics of Anti-NCA-95 Monoclonal Antibody (항 NCA-95 단일클론항체의 $^{99m}Tc$표지 키트 제조 및 특성 연구)

  • Hong, Mee-Kyoung;Jeong, Jae-Min;Chung, June-Key;Choi, Seok-Rye;Kim, Chae-Kyun;Lee, Yong-Jin;Lee, Dong-Soo;Lee, Myung-Chul;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
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    • v.30 no.4
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    • pp.541-547
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    • 1996
  • The previous monoclonal antibody labeling method for bone marrow immunoscintigrapy was complicated and laborious for clinical application. Also it showed a relatively low labeling efficiency. To improve this procedure, we compared several direct labeling methods of $^{99m}Tc$. 1) The labeling efficiency in the method using gluconate as a transchelator was low (40-70%), but immunoscintigraphy using this radiotracer produced a clear image. 2) To improve labeling efficiency, ${\beta}$-mercaptoethanol was removed after reduction. The labeling efficiency was improved up to 70-80%, but the radioactivity of the blood pool was high. 3) The higest labeling efficiency (>90%) and best quality images could be obtained by using MDP as a transchelating agent. It did not require additional procedures for separation of labeled antibodies. The immunoreactivity of this antibody was 60%. Residual MDP which can be taken up by the bone could be removed by PD-10 column. The reduced antibodies were stable with a high labeling efficiency (>90%) for up to 47 days by deep freezing. We concluded that the improved procedure for $^{99m}Tc$ labeling of anti-NCA-95 monoclonal antibody using MDP as a transchelating agent will be a simple and useful method for clinical application.

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Reducing Dose in SPECT/CT Using Adaptive Statistical Iterative Reconstruction Technique (Adaptive Statistical Iterative Reconstruction 기법을 이용한 Bone SPECT/CT 검사에서 피폭량 감소 방안)

  • Choi, Jin-Wook;Choi, Hyeon-Jun;Park, Chan-Rok;Cho, Sung-Wook;Kim, Jin-Eui;Lee, Jae-Sung;Lee, Dong-Soo
    • The Korean Journal of Nuclear Medicine Technology
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    • v.18 no.1
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    • pp.134-139
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    • 2014
  • Purpose: Adaptive statistical iterative reconstruction (ASIR) technique is a reconstruction method of CT image using statistical noise modeling which is known to reduce image noise and to preserve image quality despite reducing radiation dose. The aim of this study is to evaluate images using ASIR on bone SPECT/CT which is primarily performed in our hospital. Materials and Methods: We compared the images of applied ASIR (ASIR level: 20-80%) and none ASIR by changing the mA based on 120 kVp, 100 mA using Discovery NM/CT 670 (GE, U.S.A). First, we evaluated attenuation correction in SPECT image by changing the ASIR level using Anthropomorphic phantom. Second, we compared the contrast to noise ratio (CNR), image noise and spatial resolution in CT image using ACR phantom. Third, after selecting the ASIR level applicable patient using lower torso phantom, we examined 2 patients who followed up bone SPECT/CT and we performed blind test. Results: The degree of attenuation correction in SPECT image showed no significant difference between applied ASIR and none ASIR (P>0.05). When applied ASIR, the noise of CT image were reduced at least 17 up to 52% by changing the mA. The CNR of image with ASIR was maintained more than 0.8 at 40 mA (ASIR 60%) while those without ASIR showed 0.42 at standard 40 mA. In comparison of the high contrast object, we distinguished 12 line pairs/cm at 40 mA regardless of appling ASIR. Comparison of the patients image applied ASIR level 60% (40 mA) which found out by spine image of lower torso phantom showed no signigicant difference between applied ASIR and none ASIR in blind test. The CTDIvol and DLP for applied ASIR 60% showed decreased by 60%, 60% on average than using standard mA. Conclusion: The study show that the radiation dose in SPECT/CT using ASIR can be reduced despite degradation of SPECT and CT images. In addition, higher ASIR level could be possibly applied characteristics of SPECT/CT that region of interest is limited to bone.

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Effect of the Dose Reduction Applied Low Dose for PET/CT According to CT Attenuation Correction Method (PET/CT 저선량 적용 시 CT 감쇠보정법에 따른 피폭선량 저감효과)

  • Jung, Seung Woo;Kim, Hong Kyun;Kwon, Jae Beom;Park, Sung Wook;Kim, Myeong Jun;Sin, Yeong Man;Kim, Yeong Heon
    • The Korean Journal of Nuclear Medicine Technology
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    • v.18 no.1
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    • pp.127-133
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    • 2014
  • Purpose: Low dose of PET/CT is important because of Patient's X-ray exposure. The aim of this study was to evaluate the effectiveness of low-dose PET/ CT image through the CTAC and QAC of patient study and phantom study. Materials and Methods: We used the discovery 710 PET/CT (GE). We used the NEMA IEC body phantom for evaluating the PET data corrected by ultra-low dose CT attenuation correction method and NU2-94 phantom for uniformity. After injection of 70.78 MBq and 22.2 MBq of 18 F-FDG were done to each of phantom, PET/CT scans were obtained. PET data were reconstructed by using of CTAC of which dose was for the diagnosis CT and Q. AC of which was only for attenuation correction. Quantitative analysis was performed by use of horizontal profile and vertical profile. Reference data which were corrected by CTAC were compared to PET data which was corrected by the ultra-low dose. The relative error was assessed. Patients with over weighted and normal weight also underwent a PET/CT scans according to low dose protocol and standard dose protocol. Relative error and signal to noise ratio of SUV were analyzed. Results: In the results of phantom test, phantom PET data were corrected by CTAC and Q.AC and they were compared each other. The relative error of Q.AC profile was been calculated, and it was shown in graph. In patient studies, PET data for overweight patient and normal weight patient were reconstructed by CTAC and Q.AC under routine dose and ultra-low dose. When routine dose was used, the relative error was small. When high dose was used, the result of overweight patient was effectively corrected by Q.AC. Conclusion: In phantom study, CTAC method with 80 kVp and 10 mA was resulted in bead hardening artifact. PET data corrected by ultra- low dose CTAC was not quantified, but those by the same dose were quantified properly. In patients' cases, PET data of over weighted patient could be quantified by Q.AC method. Its relative difference was not significant. Q.AC method was proper attenuation correction method when ultra-low dose was used. As a result, it is expected that Q.AC is a good method in order to reduce patient's exposure dose.

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Impacts of Climate Change and Follow-up Cropping Season Shift on Growing Period and Temperature in Different Rice Maturity Types (미래 기후변화 및 그에 따른 재배시기 조정이 벼 생태형별 생육기간과 생육온도에 미치는 영향)

  • Lee, Chung-Kuen;Kwak, Kang-Su;Kim, Jun-Hwan;Son, Ji-Young;Yang, Won-Ha
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.56 no.3
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    • pp.233-243
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    • 2011
  • This experiment was conducted to investigate the effect of future climate change on growing period and temperature in different rice maturity types as global warming progressed, where Odaebyeo, Hwaseongbyeo, Ilpumbyeo were used as a representative cultivar of early, medium, and medium-late rice maturity type, respectively, and A1B scenario was applied to weather data for future climate change at 57 sites in Korea. When cropping season was not adjusted to climate change, entire growing period and growing temperature were shorten and risen, respectively, as global warming progressed. On the other side, when cropping season was adjusted to climate change, growing period and temperature after heading date were not changed in contrast to growing period and growing temperature before heading which were more seriously shortened and risen as global warming progressed than in not adjusted cropping season. It is supposed that adjusting cropping season to climate change can alleviate rice yield reduction and quality deterioration to some degree by improving growing temperature condition during grain-filling period, but also still have a limit such as seriously shortened growing period indicating that there need to develope actively new rice cultivation methods and varieties for future climate change.

Fertilizer and Organic Inputs Effects on CO2 and CH4 Emission from a Soil under Changing Water Regimes (토양 수분 변동 조건에서 시비 및 유기물 투입에 따른 CO2와 CH4 방출 특성)

  • Lim, Sang-Sun;Choi, Woo-Jung;Kim, Han-Yong
    • Korean Journal of Environmental Agriculture
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    • v.31 no.2
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    • pp.104-112
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    • 2012
  • BACKGROUND: Agricultural inputs (fertilizer and organic inputs) and water conditions can influence $CH_4$ and $CO_2$ emission from agricultural soils. This study was conducted to investigate the effects of agricultural inputs (fertilizer and organic inputs) under changing water regime on $CH_4$ and $CO_2$ emission from a soil in a laboratory incubation experiment. METHODS AND RESULTS: Four treatments were laid out: control without input and three type of agricultural inputs ($(NH_4)_2SO_4$, AS; pig manure compost, PMC; hairy vetch, HV). Fertilizer and organic inputs were mixed with 25 g of soil at 2.75 mg N/25 g soil (equivalent to 110 kg N/ha) in a bottle with septum, and incubated for 60 days. During the first 30-days incubation, the soil was waterlogged (1 cm of water depth) by adding distilled water weekly, and on 30 days of incubation, excess water was discarded then incubated up to 60 days without addition of water. Based on the redox potential, water regime could be classified into wetting (1 to 30 days), transition (31 to 40 days), and drying periods (41 to 60 days). Across the entire period, $CH_4$ and $CO_2$ flux ranged from 0 to 13.8 mg $CH_4$/m/day and from 0.4~1.9 g $CO_2$/m/day, and both were relatively higher in the early wetting period and the boundary between transition and drying periods. During the entire period, % loss of C relative to the initial was highest in HV (16.4%) followed by AS (8.1%), PMC (7.5%), and control (5.4%), indicating readily decomposability of HV. Accordingly, both $CH_4$ and $CO_2$ fluxes were greatest in HV treatment. Meanwhile, the lower $CH_4$ flux in AS and PMC treatments than the control was ascribed to reduction in $CH_4$ generation due to the presence of oxidized compounds such as ${SO_4}^{2-}$, $Fe^{3+}$, $Mn^{4+}$, and ${NO_3}^-$ that compete with precursors of $CH_4$ for electrons. CONCLUSION: Green manure such as HV can replace synthetic fertilizer in terms of N input, however, it may increase $CH_4$ emission from soils. Therefore, co-application of green manure and livestock manure compost needs to be considered in order to achieve satisfactory N supply and to mitigate $CH_4$ and $CO_2$ emission.

Effect of Octreotide on Patients with Malignant Bowel Obstruction (악성장폐색 환자에서 Octreotide의 치료 효과)

  • Park, Ji-Chan;Jang, Yi-Sun;Jeon, Eun-Kyoung;Kim, Dong-Kyu;Lee, Wook-Hyun;Lee, Guk-Jin;You, Si-Young;Choi, Hyun-Ho;Park, Suk-Young
    • Journal of Hospice and Palliative Care
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    • v.12 no.4
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    • pp.194-198
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    • 2009
  • Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea Purpose: Malignant bowel obstruction causes gastrointestinal symptoms and leads to diminished quality of life in patients with advanced cancer. Several studies have shown the efficacy of octreotide for the relief of malignant bowel obstruction-related symptoms. The aim of this study is to assess the efficacy and safety of octreotide in patients with malignant bowel obstruction. Methods: We retrospectively reviewed medical records of twenty nine patients who had suffered from malignant bowel obstruction without clinical improvement of conservative care and subsequently, received octreotide treatment. Initial dosage of octreotide was 0.1 mg/day, and dose was escalated depending on the clinical effect. For each patient, we assessed visual analogue scale (VAS) of pain, number of vomiting episode, and amount of nasogastric tube drainage. Results: Median dosage of octreotide was 0.2 mg/day (range 0.1~0.6), and median duration from initial medication to death was 20 days (range 2~103). VAS before and after octreotide treatment were 5.6$\pm$1.24, and 2.7$\pm$0.96, respectively. The numbers of vomiting episode before and after octreotide treatment were 3.6/day$\pm$2.5, and 0.4/day$\pm$0.8, respectively. The mean amounts of nasogastric tube drainage before and after octreotide treatment were 975$\pm$1,083 cc/day and 115$\pm$196 cc/day, respectively. Statistically significant reduction in VAS, the number of vomiting episode and the amount of nasogastric tube drainage were observed after octreotide treatment (P<0.05). Conclusion: Administration of octreotide in patients with malignant bowel obstruction, which is uncontrolled by other medication, was effective and safe. In such clinical situations, physicians should consider to add of octreotide for symptomatic control.

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Outbreak of Scion Root from 'Shiranuhi Mandarin' Hybrid Tree in Plastic Film House (부지화 감귤에서 자근의 발생)

  • Kang, Seok-Beom;Moon, Young-Eel;Lee, Dong-Hoon;Kim, Yong-Ho;Han, Seung-Gab;Chae, Chi-Won
    • Korean Journal of Environmental Agriculture
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    • v.31 no.4
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    • pp.313-317
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    • 2012
  • BACKGROUND: Citrus is usually propagated by grafting onto a rootstock. In Korea, As trifoliate orange (Poncirus trifoliata) has dwarf and strong cold hardness, it is widely used as the rootstock of satsuma mandarin. Because 'Shiranuhi' ((Citrus unshiu ${\times}$ C. sinensis) ${\times}$ C. reticulata), a kind of citrus, also, generally is grafted onto a trifoliate orange, most of farmer has been recognized that 'Shiranuhi' root is naturally trifoliate orange. Meanwhile, reduction of flowering in 'Shiranuhi' orchard has been issued among the farmers and researchers over past few years and they guessed it was occurred by severe prune, oversupply of fertilization, overfruiting and temperature of growth period. However, a few researchers strongly assumed that it would be caused by scion rooting of 'Shiranuhi'. So, this study was carried out to identify the existence of scion rooting in 'Shiranuhi' tree in Korea. METHODS AND RESULTS: To identify the existence of scion rooting in 'Shiranuhi' tree, we randomly selected six 'Shiranuhi'orchards and we surveyed three to four trees, which flowering was not enough, from six 'Shiranuhi' orchards respectively. We took the root samples of 'Shiranuhi' mandarin, and then separated the two group which were non-scion rooting (Trifoliate orange), and scion rooting ('Shiranuhi' mandarin). To identity the scion rooting, we used primer set of three types which were a F2/R15, F4/R15 and F5/R15 primer set. As a result, when we conducted the DNA analysis, fourteen tree in less bloomed twenty tree was proved as tree with the scion rooting of 'Shiranuhi' mandarin. CONCLUSION(S): Scion roots of 'Shiranuhi'mandarin were usually observed in a deeply planted tree, and xylem of 'Shiranuhi' root indicated more white color than a case of trifoliata orange. 'Shiranuhi' tree by scion rooting was more vigorous but less flowering than trees grafted onto trifoliata orange. When we used F2/R15, F4/R15 and F5/R15 primer set for discriminance of 'Shiranuhi'mandarin root and trifoliate root, we identified the existence of scion rooting in 'Shiranuhi', From our results, it is suggested that the influence of scion root should be reviewed in 'Shiranuhi'orchards.

Optimal Application Rate of Mixed Expeller Cake and Rice Straw and Impacts on Physical Properties of Soil in Organic Cultivation of Tomato (토마토 유기재배에서 혼합유박과 볏짚의 적정시용량 및 토양 물리성에 미치는 영향)

  • Lim, Tae-Jun;Park, Jin-Myeon;Lee, Seong-Eun;Jung, Hyun-Cheol;Jeon, Sang-Ho;Hong, Soon-Dal
    • Korean Journal of Environmental Agriculture
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    • v.30 no.2
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    • pp.105-110
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    • 2011
  • BACKGROUND: In this study, 5 different treatments such as non-treatment, mixed expeller cake 1.0 N (standard nitrogen fertilizer), rice straw, rice straw+mixed expeller cake 0.5 N, rice straw+mixed expeller cake 1.0 N were performed over 4 cropping seasons over 2 years in order to identify the optimal application rate of mixture of rice straw and mixed expeller cake, organic source in organic cultivation of tomatoes. METHODS AND RESULTS: There was no difference in all treatments in case of 200 mg/kg in the nitrate nitrogen content in soil prior to the first cropping season test under the criteria for nitrogen nutrient based on yield of crops, cultivation without fertilizers seems possible. But in the second cropping season, no treatment and rice straw showed the reduction of yield and in the third cropping season, rice-straw+mixed expeller cake 0.5 N treatment showed the significant difference. The content of nitrate nitrogen in soil prior to cropping seasons was evaluated in 160 mg/kg and standard fertilization such as mixed expeller cake, source of nitrogen, are needed due to the deficiency of nitrogen. In terms of application of organic resources, rice straw showed the effects of improvements on physical properties of soil such as bulk density, cation exchange capacity and humus contents, but the mixed expeller cake did not show any significant differences in improvements on physical properties of soil. CONCLUSION(s): Fertilizer management in organic cultivation of tomatoes is thought to produce the reliable quantity of crops as well as keep the high quality of soils by using the optimal application rate of mixed expeller cake according to the contents of nitrate nitrogen in soil and rice straw which improves the physical properties of soil.

Lung Volumes and Diffusing Capacity in Bronchiectasis: Correlation with the Findings of High Resolutional CT (기관지확장증의 흉부고해상전산화단층촬영소견과 폐기량 및 폐확산능과의 관계)

  • Kim, Yeon-Jae;Park, Jae-Yong;Won, Jun-Hee;Kim, Chang-Ho;Kang, Duk-Sik;Jung, Tae-Hoon
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.4
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    • pp.489-499
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    • 1999
  • Background: The patient with bronchiectasis may have obstructive ventilatory impairment combined with mild restrictive ventilatory impairment due to fibrosis of surrounding lung parenchyme and pleural adhesions caused by chronic recurrent pulmonary infections. Since hyperinflation or emphysematous change can be occured in bronchiectasis, pulmonary functions such as lung volumes and diffusing capacity may also vary with associated emphysema. Methods: For the evaluation of lung volumes and diffusing capacity in bronchiectasis with respect to the anatomic types and severity of bronchiectasis, a total of 40 cases comprising 24 cases of tubular, and 16 cystic type of bronchiectasis were analyzed retrospectively. Correlation between lung functions and extent of bronchiectasis or associated emphysema detected in HRCT were also evaluated. Results: Vital capacity(VC) tended to decrease in cystic type than in tubular type. As the severity of bronchiectasis became serious, the VC were significantly reduced, whereas the total lung capacity(TLC), residual volume(RV) and its ratio to the total lung capacity(RV/TLC) had no significant difference. Lung clearance index(LCI) was significantly increased in cystic type than in tubular type, whereas the slope of phase III in single breath nitrogen curve($\triangle$N2/L) was not significantly changed regard to the type and severity of bronchiectasis. DLCO and DLCO/VA reflecting diffusing capacity were significantly decreased in cystic type and also as the severity of bronchiectasis became serious. The correlation coefficient of VC, DLCO and LCI with the extent of bronchiectasis were -0.322, -0.339 and 0.487, respectively, whereas other parameters were not significantly correlated with the extent of bronchiectasis. VC and DLCO correlated negatively with the extent of emphysema while RV, RV/TLC, LCI and $\triangle$N2/L correlated positively. Conclusion: These findings suggest that the reduction of VC and diffusing capacity or uneven distribution of inspired gas in bronchiectasis are related to both the extent of bronchiectasis and associated emphysema while increased residual volume be related to the extent of associated emphysema alone.

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