• 제목/요약/키워드: Square Method

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Reproducibility of Gated Myocardial Perfusion SPECT for the Assessment of Myocardial Function: Comparison with Thallium-201 and Technetium-99m-MIBI (심근 기능 측정에 사용된 게이트 심근 관류 SPECT 방법의 재현성 평가: $^{201}Tl$$^{99m}Tc$-MIBI 게이트 SPECT의 비교)

  • Hyun, In-Young;Seo, Jeong-Kee;Hong, Eui-Soo;Kim, Dae-Hyuk;Kim, Sung-Eun;Kwan, Jun;Park, Keum-Soo;Choe, Won-Sick;Lee, Woo-Hyung
    • The Korean Journal of Nuclear Medicine
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    • 제34권5호
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    • pp.381-392
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    • 2000
  • Purpose: We compared the reproducibility of $^{201}Tl\;and\;^{99m}Tc$-sestamibi (MIBI) gated SPECT measurement of myocardial function using the Germano algorithm Materials and Methods: Gated SPECT acquisition was repeated in the same position in 30 patients who received $^{201}Tl$ and in 26 who received $^{99m}Tc$-MIBI. The quantification of end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) on $^{201}Tl\;and\;^{99m}Tc$-MIBI gated SPECT was processed independently using Cedars quantitative gated SPECT software. The reproducibility of the assessment of myocardial function on $^{201}Tl$ gated SPECT was compared with that of $^{99m}Tc$-MIBI gated SPECT Results: Correlation between the two measurements for volumes and EF was excellent by the repeated gated SPECT studies of $^{201}Tl$ (r=0.928 to 0.986; p<0.05) and $^{99m}Tc$-MIBI (r=0.979 to 0.997; p<0.05). However, Bland Altman analysis revealed the 95% limits of agreement (2 SD) for volumes and EF were tighter by repeated $^{99m}Tc$-MIBI gated SPECT (EDV: 14.1 ml, ESV: 9.4 ml and EF: 5.5%) than by repeated $^{201}Tl$ gated SPECT (EDV: 24.1 ml, ESV: 18.6 ml and EF: 10.3%). The root mean square (RMS) values of the coefficient of variation (CV) for volumes und EFs were smaller by repeated $^{99m}Tc$-MIBI gated SPECT (EDV: 2.1 ml, ESV 2.7 ml and EF: 2.3%) than by repeated $^{201}Tl$ gated SPECT (EDV: 3.2 ml, ESV: 3.5 ml and EF: 5.2%). Conclusion: $^{99m}Tc$-MIBI provides more reproducible volumes and EF than $^{201}Tl$ on repeated acquisition gated SPECT. $^{99m}Tc$-MIBI gated SPECT is the preferable method for the clinical monitoring of myocardial function.

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The Effects of PBL(Problem-Based Learning) on Academic Resilience, Learning Flow, and Academic Motivation of Nursing Students (문제중심학습이 간호대학생의 학업 탄력성, 학습 몰입, 학업 동기에 미치는 효과)

  • Kang, Myungsuk;Park, Yoon-Jin;Choi, Seonyoung;Lee, Su-Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제19권6호
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    • pp.291-298
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    • 2018
  • Purpose: The purpose of this study was to identify the effects of Problem-Based Learning on Academic Resilience, Learning Flow, and Academic Motivation in nursing students. Methods: Research design was a non-equivalent control group pretest-posttest design. The participants were 121 sophomore nursing students from two universities. They were divided into the Problem-Based Learning group (n=61) and Lecture-Based Learning group (n=60). The data were analyzed by Chi-square, paired t-test, and independent t-test. Results: In the PBL group, there was statistically significant improvement in Academic Resilience after intervention (pretest $3.88{\pm}.36$, posttest $4.00{\pm}.38$, p<.001). However, no statistically significant difference was found in the Lecture-Based Learning (LBL) group (pretest $3.86{\pm}.43$, posttest $3.93{\pm}.17$). In terms of Learning Flow, there was statistically significant improvement in the PBL group (pretest $3.31{\pm}.41$, posttest $3.51{\pm}.42$). However, no significant change was identified in the LBL group (pretest $3.45{\pm}.42$, posttest $3.48{\pm}.47$. Academic motivation was improved in the LBL group (pretest $3.32{\pm}.30$, posttest $3.46{\pm}.32$, p=.002) as well as in the PBL group (pretest $3.26{\pm}.23$, posttest $3.47{\pm}.21$, p<.001). Both results were statistically significant. Conclusion: These results suggest that Problem-Based Learning could be more effective for nursing students in improving their academic achievement. Further studies need to be investigated.

The Molecular Weight Dependance of Paramagnetic Gd-chelates on T1 and T2 Relaxation Times (상자성 복합체의 분자량에 따른 T1 및 T2 자기이완시간에 관한 연구)

  • Kim In-Sung;Lee Young-Ju;Kim Ju-Hyun;Sujit Dutta;Kim Suk-Kyung;Kim Tae-Jeong;Kang Duk-Sik;Chang Yong-Min
    • Progress in Medical Physics
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    • 제17권2호
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    • pp.61-66
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    • 2006
  • To evaluate the T1, T2 magnetic relaxation properties of water molecule according to molecular weight of paramagnetic complex. 4-aminomethyicyclohexane carboxylic acid (0.63 g, 4 mmol) was mixed with the suspension solution of DMF (15 ml) and DTPA-bis-anhydride (0.71 g, 2 mmol) to synthesize the ligand. The ligand was then mixed with $Gd_2O_3$ (0.18 g, 0.5 mmol) to synthesize Gd-chelate. For the measurement of magnetic relaxivity of paramagnetic compounds, the compounds were diluted to 1 mM and then the relaxation times were measured at 1.57 (64 MHz). Inversion-recovery pulse sequence was employed for T1 relaxation measurement and CPMG (Carr-Purcell-Meiboon-Gill) pulse sequence was employed for T2 relaxation measurement. In case of inversion recovery sequence, total 35 images with different inversion time(T1)s ranging from 50 msec to 1,750 msec. To estimate the relaxation times, the signal intensity of each sample was measured using region of Interest (ROI) and then fitted by non-linear least square method to yield T1, T2 relaxation times and also R1 and R2. Compared to T1=($205.1{\pm}2.57$) msec and T2=($209.4{\pm}4.28$) msec of Omniscan (Gadodiamide), which is commercially available paramagnetic MR agent, T1 and T2 values of new paramagnetic complexes were reduced along with their molecular weight. That is, T1 value was ranged from $(96.35{\pm}2.04)\;to\;(79.38{\pm}1.55)$ msec and T2 value was ranged from $(91.02{\pm}2.08)\;to\;(76.66{\pm}1.84)$ msec. Among new paramagnetic complexes, there is a tendency that the R1 and R2 increase as the molecular weight is increases. As molecular weight of paramagnetic complex increases, T1 and T2 relaxation times reduce and thus the increase of relaxivity (R1 and R2) Is proportional to molecular weight.

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The Acceptance Testing of 5 Mega Pixels Primary Electronic Display Devices and the Study of Quality Control Guideline Suitable for Domestic Circumstance (5 Mega 화소 진단용 전자표시장치 인수검사 및 국내 실정에 적합한 정도관리 가이드라인 연구)

  • Jung, Hai-Jo;Kim, Hee-Joung;Kim, Sung-Kyu
    • Progress in Medical Physics
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    • 제18권2호
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    • pp.98-106
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    • 2007
  • In June 2005, Yonsei University Medical Center, Severance Hospital upgraded a full-PACS system by adding twenty (5 mega pixels) Totoku ME511L flat panel LCD display devices for diagnostic interpretation purposes. Here we report upon the quantitative (or visual) acceptance testing of the twenty Totoku ME511L display devices for reflection, luminance response, luminance spatial dependency, resolution, noise, veiling glare, and display chromaticity based on AAPM TG 18 report. The tools used in the tests included a telescopic photometer, which was used as a colorimeter, illuminance meter, light sources for reflection assessment, light-blocking devices, and digital TG18 test patterns. For selected 8 flat panel displays, mean diffuse reflection coefficient ($R_d$) was $0.019{\pm}0.02sr^{-1}$. In the luminance response test, luminance ratio (LR), maximum luminance difference ($L_{max}$), and deviation of contrast response were $550{\pm}100,\;2.0{\pm}1.9%\;and\;5.8{\pm}1.8%$, respectively. In the luminance uniformity test, maximum luminance deviation was $14.3{\pm}5.5%$ for the 10% luminance of the TG18-UNL10 test pattern. In the resolution test with luminance measurement method, percent luminance (${\Dalta}L$) at the center was $0.94{\pm}0.64%$. In all cases of noise testing, rectangular target In every square in the three quadrants was visible and all 15 targets except the smallest one in the every corner pattern and the center pattern. The glare ratio (GR) was $12,346{\pm}1,995$. The color uniformity, (u',v'), was $0.0025{\pm}0.0008$. Also, the research results of qualify control guideline of primary disply devices suitable for domestic circumstance are presented All test results are in-line with the criteria recommended by AAPM TG18 report and are thus fully acceptable for diagnostic image interpretation. As a result, the acceptance testing schedule described provides not only an acceptance standard but also guidelines for quality control, optimized viewing conditions, and a means for determining the upgrading time of LCD display devices for diagnostic interpretation.

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Effect of Microbial Additives on Metabolic Characteristics in Sheep and Milking Performance of Lactating Dairy Cows (미생물제제의 첨가가 면양의 반추대사 및 젖소의 유생산성에 미치는 영향)

  • Kim, G.L.;Choi, S.K.;Choi, S.H.;Song, M.K.
    • Journal of Animal Science and Technology
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    • 제49권6호
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    • pp.819-828
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    • 2007
  • Two experiments were conducted to observe the effects of direct fed microbials on metabolic characteristics in sheep and milking performance in dairy cows. A metabolic trial with four ruminally cannulated sheep(60±6kg) was conducted in a 4×4 Latin square design to investigate the supplementation effects of Saccharomyces cerevisiae, Clostridium butyricum or mixed microbes of S. cerevisiae and C. butyricum on ruminal fermentation characteristics and whole tract digestibility. Sheep were fed 1.25 kg of total mixed ration(TMR, DM basis) supplemented with S. cerevisiae (2.5g/day), C. butyricum (1.0g/day) or its mixture(S. cerevisiae 1.25g/day+C. butyricum 1g/day), twice daily in an equal volume. But control sheep were fed only TMR. A feeding trial with 28 lactating Holstein cattle was also conducted for 12 weeks to investigate the effects of the same microbial supplements as for the metabolic trial on milking performance. The cows were fed the TMR(control), and fed S. cerevisiae(50g/day), C. butyricum(15g/day) or its mixture (S. cerevisiae 25g/day + C. butyricum 7.5g/day) with upper layer dressing method. Total VFA concentration and the digestibility of whole digestive tract in the sheep increased by supplementation of S. cerevisiae, C. butyricum or their combined microbials compare to control group. The proportion of propionic acid at 1h(P<0.039) and 3h(P<0.022) decreased by supplementation of S. cerevisiae while tended to increase acetic acid proportion at the same times. Daily dry matter intake(DMI) was not influenced by the microbial treatments, but milk yield(P<0.031) and feed efficiency(milk yield/DMI, P<0.043) were higher for the cow received C. butyricum than those for other treatments. The milk fat content was higher (P<0.085) when cows fed S. cerevisiae(4.11%) than that fed the control (4.08%), the diets with C. butyricum (3.85%) and the microbial mixture. Based on the results obtained from the current experiments, supplementation of C. butyricum or mixture with S. cerevisiae might be increased milk fat content and milk productivity of lactating daily cows. (Key words:Saccharomyces cerevisiae, Clostridium butyricum, Fermentation characteristics,

Accelerated Hyperfractionated Radiotherapy for Locally Advanced Uterine Cervix Cancers (국소진행된 자궁경부암에서의 가속과분할 방사선치료)

  • Seo, Young-Seok;Cho, Chul-Koo;Yoo, Seong-Yul;Kim, Mi-Sook;Yang, Kang-Mo;Yoo, Hyung-Jun;Choi, Chul-Won;Lee, Kyung-Hee;Lee, Eui-Don;Rhu, Sang-Young;Choi, Suck-Chul;Kim, Moon-Hong;Kim, Beob-Jong
    • Radiation Oncology Journal
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    • 제26권1호
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    • pp.24-34
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    • 2008
  • Purpose: To assess the efficacy of the use of accelerated hyperfractionated radiotherapy(AHRT) for locally advanced uterine cervix cancers. Materials and Methods: Between May 2000 and September 2002, 179 patients were identified with FIGO stage IIB, IIIB, and IVA cancers. Of the 179 patients, 45 patients were treated with AHRT(AHRT group) and 134 patients were treated with conventional radiotherapy(CRT group), respectively. Patients undergoing the AHRT regimen received a dose of 30 Gy in 20 fractions(1.5 $Gy{\times}2$ fractions/day) to the whole pelvis. Subsequently, with a midline block, we administered a parametrial boost with a dose of 20 Gy using 2 Gy fractions. Patients also received two courses of low-dose-rate brachytherapy, up to a total dose of 85{\sim}90 Gy to point A. In the CRT group of patients, the total dose to point A was $85{\sim}90$ Gy. The overall treatment duration was a median of 37 and 66 days for patients that received AHRT and CRT, respectively. Statistical analysis was calculated by use of the Kaplan-Meier method, the log-rank test, and Chi-squared test. Results: For patients that received cisplatin-based concurrent chemotherapy and radiotherapy, the local control rate at 5 years was 100% and 79.2% for the AHRT and CRT group of patients, respectively(p=0.028). The 5-year survival rate for patients with a stage IIB bulky tumor was 82.6% and 62.1% for the AHRT group and CRT group, respectively(p=0.040). There was no statistically significant difference for severe late toxicity between the two groups(p=0.561). Conclusion: In this study, we observed that treatment with AHRT with concurrent chemotherapy allows a significant advantage of local control and survival for locally advanced uterine cervix cancers.

Fabrication and Characteristics of Zinc Oxide- and Gallium doped Zinc Oxide thin film transistor using Radio Frequency Magnetron sputtering at Room Temperature (Zinc Oxide와 갈륨이 도핑 된 Zinc Oxide를 이용하여 Radio Frequency Magnetron Sputtering 방법에 의해 상온에서 제작된 박막 트랜지스터의 특성 평가)

  • Jeon, Hoon-Ha;Verma, Ved Prakash;Noh, Kyoung-Seok;Kim, Do-Hyun;Choi, Won-Bong;Jeon, Min-Hyon
    • Journal of the Korean Vacuum Society
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    • 제16권5호
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    • pp.359-365
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    • 2007
  • In this paper we present a bottom-gate type of zinc oxide (ZnO) and Gallium (Ga) doped zinc oxide (GZO) based thin film transistors (TFTs) through applying a radio frequency (RF) magnetron sputtering method at room temperature. The gate leakage current can be reduced up to several ph by applying $SiO_2$ thermally grown instead of using new gate oxide materials. The root mean square (RMS) values of the ZnO and GZO film surface were measured as 1.07 nm and 1.65 nm, respectively. Also, the transmittances of the ZnO and GZO film were more than 80% and 75%, respectively, and they were changed as their film thickness. The ZnO and GZO film had a wurtzite structure that was arranged well as a (002) orientation. The ZnO TFT had a threshold voltage of 2.5 V, a field effect mobility of $0.027\;cm^2/(V{\cdot}s)$, a on/off ratio of $10^4$, a gate voltage swing of 17 V/decade and it operated in a enhancement mode. In case of the GZO TFT, it operated in a depletion mode with a threshold voltage of -3.4 V, a field effect mobility of $0.023\;cm^2/(V{\cdot}s)$, a on/off ratio of $2{\times}10^4$ and a gate voltage swing of 3.3 V/decade. We successfully demonstrated that the TFTs with the enhancement and depletion mode type can be fabricated by using pure ZnO and 1wt% Ga-doped ZnO.

A Computer Simulation for Small Animal Iodine-125 SPECT Development (소동물 Iodine-125 SPECT 개발을 위한 컴퓨터 시뮬레이션)

  • Jung, Jin-Ho;Choi, Yong;Chung, Yong-Hyun;Song, Tae-Yong;Jeong, Myung-Hwan;Hong, Key-Jo;Min, Byung-Jun;Choe, Yearn-Seong;Lee, Kyung-Han;Kim, Byung-Tae
    • The Korean Journal of Nuclear Medicine
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    • 제38권1호
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    • pp.74-84
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    • 2004
  • Purpose: Since I-125 emits low energy (27-35 keV) radiation, thinner crystal and collimator could be employed and, hence, it is favorable to obtain high quality images. The purpose of this study was to derive the optimized parameters of I-125 SPECT using a new simulation tool, GATE (Geant4 Application for Tomographic Emission). Materials and Methods: To validate the simulation method, gamma camera developed by Weisenberger et al. was modeled. Nal(T1) plate crystal was used and its thickness was determined by calculating detection efficiency. Spatial resolution and sensitivity curves were estimated by changing variable parameters for parallel-hole and pinhole collimator. Peformances of I-125 SPECT equipped with the optimal collimator were also estimated. Results: in the validation study, simulations were found to agree well with experimental measurements in spatial resolution (4%) and sensitivity (3%). In order to acquire 98% gamma ray detection efficiency, Nal(T1) thickness was determined to be 1 mm. Hole diameter (mm), length (mm) and shape were chosen to be 0.2:5:square and 0.5:10:hexagonal for high resolution (HR) and general purpose (GP) parallel-hole collimator, respectively. Hole diameter, channel height and acceptance angle of pinhole (PH) collimator were determined to be 0.25 mm, 0.1 mm and 90 degree. The spatial resolutions of reconstructed image of the I-125 SPECT employing HR:GP:PH were 1.2:1.7:0.8 mm. The sensitivities of HR:GP:PH were 39.7:71.9:5.5 cps/MBq. Conclusion: The optimal crystal and collimator parameters for I-125 Imaging were derived by simulation using GATE. The results indicate that excellent resolution and sensitivity imaging is feasible using I-125 SPECT.

Seasonal sea Level oscillations in the East Sea (Sea of Japan) (동해 해수면의 계절적인 변동에 대하여)

  • OH, IM SANG;RABINOVICH, ALEXANDER B.;PARK, MYOUNG SOOK;MANSUROV, ROALD N.
    • 한국해양학회지
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    • 제28권1호
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    • pp.1-16
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    • 1993
  • The monthly mean sea levels at 48 stations located at the East and Yellow Seas coasts of Korea, Russia and Japan are processed to investigate seasonal sea level variations. The strong seasonal variations are found to be at the west coast of Korea (42.1 cm in Kunsan), in the region of the Korea strait and near the southern part of Primorye (30-33 cm); the weak ones near the southwestern coast of the Sakhalin Island (10-12 cm). Practically for the whole study area except the southwest Sakhalin, the general picture of the seasonal sea level changes is alike: the mean sea level rises in summer-autumn and falls in winter-spring. The spectral analysis of the records also shows that the seasonal oscillations strongly dominate in the sea level variations, more than 80% or total energy in the southern part of the investigated region and 50-70% in the northern part relate to these oscillations. The annal peak significantly prevails in spectra of the monthly sea levels for the majority of stations, the semiannual peak is also well manifested, but the seasonal peaks of higher order (corresponding to the periods of four and three months) reveal only at some records. The maximal amplitudes of annual component by a least square method are found at the Yellow Sea coast of Korea (20-21 cm) and also near the Japanese coast of the korea Strait (19-19 cm). The semiannual component has the maximal amplitudes (3-4 cm) near the south and southwestern coasts of the Sakhalin Island. The annual range of the sea levels is much weaker here than in the other regions, the relative investment of the seasonal oscillations in total energetic budget is only 35-40%, annual ($A_1$) and semiannual ($A_2$) components have nearly the same amplitude (seasonal factor $F=A_1/A_2=0.9-1.2$). On the basis of the present examination on sea level changes together with the results of Tomizawa et. al.(1984) the whole investigated area may be divided into 10 subregions, 2 of them are related to the Yellow Sea and Western part of the Korea Strait (Y1, Y2), the other ones (E1-E8) to the East Sea.

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Development of Porcine Pericardial Heterograft for Clinical Application (Tensile Strength-thickness) (돼지의 심낭을 이용한 이종이식 보철편의 개발 (장력-두께간의 구조적 특성))

  • Kim, Kwan-Chang;Lee, Cheul;Choi, Chang-Hue;Lee, Chang-Ha;Oh, Sam-Sae;Park, Seong-Sik;Kim, Kyung-Hwan;Kim, Woong-Han;Kim, Yong-Jin
    • Journal of Chest Surgery
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    • 제41권2호
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    • pp.170-176
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    • 2008
  • Background: Bioprosthetic devices for treating cardiovascular diseases and defects may provide alternatives to autologous and homograft tissue. We evaluated the mechanical and physical conditions of a porcine pericardial bioprosthesis treated with Glutaraldehyde (GA), Ethanol, or Sodium dodecylsulfate (SDS) before implantation. Material and Method: 1) Thirty square-shaped pieces of porcine pericardium were fixed in 0.625%, 1.5% or 3% GA solution. 2) The tensile strength and thickness of these and other bioprosthesis, including fresh porcine pericardium, fresh human pericardium, and commercially produced heterografts, were measured. 3) The tensile strength and thickness of the six treated groups (GA-Ethanol, Ethanol-GA, SDS only, SDS-GA, Ethanol-SDS-GA and SDS-Ethanol-GA) were measured. Result: 1) Porcine pericardium fixed in 0.625% GA the thinnest and had the lowest tensile strength, with thickness and tensile strength increasing with the concentration of GA solution. The relationship between tensile strength and thickness of porcine pericardium increased at thicknesses greater than 0.1mm (correlation-coefficient 0.514, 0<0.001). 2) There were no differences in tensile strength or thickness between commercially-produced heterografts. 3) Treatment of GA, ethanol, or SDS minimally influenced thickness and tensile strength of porcine pericardium, except for SDS alone. Conclusion: Porcine pericardial bioprosthesis greater than 0.1 mm thick provide better handling and advantageous tensile strength. GA fixation did not cause physical or mechanical damage during anticalcification or decellularization treatment, but combining SDS-ethanol pre-treatment and GA fixation provided the best tensile strength and thickness.