• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.81-85
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• 2009

Purpose: The examination of nuclear medicine observes the change in accordance with the time elapsed in the same region purposed and there are many examinations to acquire the image during the same term. At this time, the same parameter should be applied. The hepatobiliary scan, lung scan etc, are the acquired examination in the divided time with a regular term. Pre-set time that is applied in continued next image is set in order to acquire the fixed counts. The same scan time should be applied for each image. This study will look for the rational plan and analyze the change of scan time in accordance with the time of the decision of scan time at examination that pre-set time is applied. Methods: The hapatobiliary scan that use the radio pharmaceutical $^{99m}Tc$-mebrofenin is choosed as compensation from Jan. 2009 to Mar. 2009 in the department of nuclear medicine in ASAN MEDICAL CENTER. Scan is started after 5 minutes from when 222 MBq (6 mCi) is injected to patient. We let patient stand up between both detectors, and possibly close to the front of detector. When scan time reach 10%, 25%, 50%, 75% of total scan time, we measured the expected total scan time. After finishing all of scan, we compared the total scan time and the expected total scan time, while image is acquiring. and we observed the change of scan time in accordance with radio activity by using phantom. Results: After starting scan, a difference of when scan time reach 10%, 25%, 50%, 75% of total scan time is that the biggest difference is 5 seconds on 10%. There statistically is difference between 25% (t:2.88, p<0.01) and 50% (t:2.05, p<0.01). Conclusions: When the same the scan time is applied in the examination that acquire the many frame, concluding the same scan time has a important effect on a quantitative analysis. Although method that decide the scan time after finish all of the examinations, there is a few problem to apply practical affairs. This may cause an inaccurate result on the examination that need a quantitative analysis. We think that operator should try to improve it. At least, after reach 50% of total scan time, deciding the total scan time mean that you can minimize error of a quantitative analysis caused by unmatched scan time from a gap of image.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.83-89
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• 2010

Purpose: The Wide Beam Reconstruction (WBR) algorithms that UltraSPECT, Ltd. (U.S) has provides solutions which improved image resolution by eliminating the effect of the line spread function by collimator and suppression of the noise. It controls the resolution and noise level automatically and yields unsurpassed image quality. The aim of this study is WBR of whole body bone scan in usefulness of clinical application. Materials and Methods: The standard line source and single photon emission computed tomography (SPECT) reconstructed spatial resolution measurements were performed on an INFINA (GE, Milwaukee, WI) gamma camera, equipped with low energy high resolution (LEHR) collimators. The total counts of line source measurements with 200 kcps and 300 kcps. The SPECT phantoms analyzed spatial resolution by the changing matrix size. Also a clinical evaluation study was performed with forty three patients, referred for bone scans. First group altered scan speed with 20 and 30 cm/min and dosage of 740 MBq (20 mCi) of $^{99m}Tc$-HDP administered but second group altered dosage of $^{99m}Tc$-HDP with 740 and 1,110 MBq (20 mCi and 30 mCi) in same scan speed. The acquired data was reconstructed using the typical clinical protocol in use and the WBR protocol. The patient's information was removed and a blind reading was done on each reconstruction method. For each reading, a questionnaire was completed in which the reader was asked to evaluate, on a scale of 1-5 point. Results: The result of planar WBR data improved resolution more than 10%. The Full-Width at Half-Maximum (FWHM) of WBR data improved about 16% (Standard: 8.45, WBR: 7.09). SPECT WBR data improved resolution more than about 50% and evaluate FWHM of WBR data (Standard: 3.52, WBR: 1.65). A clinical evaluation study, there was no statistically significant difference between the two method, which includes improvement of the bone to soft tissue ratio and the image resolution (first group p=0.07, second group p=0.458). Conclusion: The WBR method allows to shorten the acquisition time of bone scans while simultaneously providing improved image quality and to reduce the dosage of radiopharmaceuticals reducing radiation dose. Therefore, the WBR method can be applied to a wide range of clinical applications to provide clinical values as well as image quality.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.1
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• pp.14-20
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• 2003

Piezoelectric ultrasonic transducers for high temperature contact measurement were developed. These high temperature ultrasonic transducers (HTUT) consisted of bismuth titanate piezoceramic element whose Curie temperature is higher than $600^{\circ}C$, a backing material of the mixture of tungsten powder and inorganic binder, an inner alumina tube, a wear Plate and a housing. The operational frequencies or the HTUT were 1.04 and 2.08 MHz, respectively. Various commercially available couplants for high temperature were evaluated and compared. As a couplant for high temperature ultrasonic testing between HTUT and test specimen, gold epoxy was selected. The peak amplitude of pulse-echo signals from steel test specimen decreased with increasing temperature. The operational temperature of the HTUT reached up to $500^{\circ}C$ at which the continuous contact measurement was possible.

• Journal of the Korean Arthroscopy Society
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• v.5 no.1
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• pp.45-48
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• 2001

The anterior horn of the medial meniscus is attached to the anterior surface of the tibia. The anterior horns of the medial and lateral menisci are connect with the transverse ligament. The posterior horn of the medial meniscus is firmly attached to the posterior aspect of the tibia just anterior to the insertion of the posterior cruciate ligament. The authors incidentally found an anomalous insertion of posterior horn of medial meniscus into the anterior horn area during arthroscopic examination in the symptomatic knee joint, which had been ruptured anterior cruciate ligament, and report with literature review.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.17-20
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• 2010

Purpose: The hepatobiliary scan is the examination which is the possibility of knowing the function of liver, gall bladder and closing of the biliary tract. Also, after subtotal gastrectomy, the increased gastric-bile reflux is known as the primary reason of reflux gastritis. In this study, according to changing the acquisition method, we tried to prove the reflux time and reflux index in patients who underwent subtotal gastrectomy. Materials and Methods: From Oct 2008 to Jan 2009, 72 patients with subtotal gastrectomy who took the hepatobiliary scan (man: 52, woman: 20, age range: 31-77, mean age: $60.5{\pm}7$) in our department. We used the radiopharmaceutical $^{99m}Tc$-mebrofenin 185 MBq/0.5 cc. After 5 minutes, we acquired 300,000 counts anterior image on supine, and then we acquired right lateral and $45^{\circ}$ LAO position by using the time setting method. We acquired 30 min, 60 min, 90 min, 120 min and fatty meal by the same method. We painted the ROI of liver, GB and CBD on 30 min anterior image and LAO image in patients had occurred the bile juice reflux. And then we painted the ROI of stomach on others image. We calculated the reflux index from those values. Results: According to this study, we found out 40 patients (55.6%) who had occurred the gastric-bile juice reflux (1 person from 30 min, 7 persons from 60 min, 4 persons from 90 min, 28 persons from after fatty meal). Hourly, the bile reflux highest level is 6 persons from 60 min, 2 persons from 90 min, 32 persons from fatty meal among those people. The reflux index of anterior is 0.85-23.36% (mean 6.53%). The reflux index of LAO is 1-29.13% (mean 8.89%). By visual assessment, we can distinguish that there were 26 of the 40 patients (65%) had occurred the reflux on LAO image more than anterior image. Conclusion: We find out that the patients with subtotal gastrectomy had occurred gastric-bile juice reflux more than 50% from hepatobiliary scan. And after eating fatty meal, we can know that it's the most possible to occur the gastric-bile juice reflux. When it happened, we have to change the acquisition method to reduce the overlap between colon and stomach. This study will be more valuable in diagnosis.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.57-61
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• 2015

Purpose We considered the correlation of Ejection Fraction (EF) which was analyzed by Multi Gated Blood Pool Scan (MUGA) and Echocardiography (ECHO) for the patients who were classified according to the condition of cardiac function. Materials and Methods We analyzed the patients (female 60) who were diagnosed with breast cancer and were examined by both MUGA and ECHO. The 30 patients (age: $58.27{\pm}13.48$) who were analyzed into less than 50% to 70% of EF were categorized as normal group and the other 30 patients (age: $53.70{\pm}8.45$) who were analyzed into less than 50% of EF were categorized as abnormal group. Statistical analysis with SPSS ver. 18 was applied. Results Each of the value of mean and standard deviation of normal group was $66.43{\pm}5.80$ (MUGA), $60.50{\pm}4.93$ (ECHO). There was a significant difference (p<0.001). Each of the value of mean and standard deviation of abnormal group was $41.93{\pm}7.58$ (MUGA), $41.70{\pm}11.49$ (ECHO). There was no significant difference (p>0.001). In the result, all 30 cases of normal group showed the same reading. 8 out of 30 cases in abnormal group showed inconsistency of the reading. Conclusion We could confirm the correlation of the EF in MUGA and ECHO statistically. There was difference between abnormal groups from the result of reading. If we are aware of the result according to the different cardiac function categorization, MUGA and ECHO can be used as even more accurate interchangeable test.

• Journal of Life Science
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• v.20 no.1
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• pp.71-76
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• 2010

The purpose of this study was to investigate the changes of long term ECG response in a company with middle-aged male employees. Subjects were 60 men who were 40~55 years old. We enrolled 30 exercise group subjects into a 3-year exercise program. In measurement index, body composition was measured by % body fat and BMI. Exercise stress test analyses were measured using ST/HR slope and QRS vector. Statistical analysis was performed using analysis of repeated ANOVA. Results of this study were as follows: In ST/HR slope, the control group showed symptoms of ischemia after nine minutes of exercise. In the rest frontal axis of the QRS vector, the control group had a tendency towards right axis deviation. In the rest horizontal amplitude of the QRS vector, the control group had a tendency to show a significant decrease, but it was increased significantly in the exercise group. These findings suggest that inactive company workers was showed a decrease of exercise capacity, early diagnosis exercise-induced ST depression, and prolonged deviation of QRS vector, but that cardiac function could be elevated in active middle aged men through regular exercise program participation.

• Journal of radiological science and technology
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• v.6 no.1
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• pp.103-113
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• 1983

Scintillation cameras을 사용(使用)할때 양질(良質)의 화상(畵像)을 얻기 위하여 camera의 성능(性能), 방사성의약품(放射性醫藥品)의 특성(特性), 그리고 적정(適正)한 촬상조건(撮像條件)을 고려할 필요(必要)가 있다. 특(特)히 RI 상(像)에 대한 촬상조건(撮像條件)은 film의 성질(性質), 상(像)의 크기, 상(像)의 농도(濃度), window, 그리고 콜리메타 전면(前面)으로부터 거리(距離) 등(等)에 따라서 좌우(左右)된다. 이러한 요인(要因)들은 각각 화상(畵像)을 만드는 과정에 영향(影響)을 미치고 있다. 그러므로 상(像)의 표준화(標準化)와 촬상방법(撮像方法)의 기준(基準)을 확립(確立)하기가 매우 어렵다. 고로 이러한 문제(問題)들을 해결(解決)하는 것은 Scintillation camera을 사용(使用)하는 핵의학적(核醫學的) 검사(檢査)에 있어서 매우 중요(重要)하다. 저자(著者)는 이러한 점(點)을 고려하여 일정(一定)한 상(像)의 농도(濃度)을 얻을 수 있는 촬상조건(撮像條件)에 대(對)하여 실험(實驗)을 하였다. 실험(實驗)에 있어서 평행다공형(平行多孔型) 콜리메타를 camera의 head에 부착(附着)시키고 $^{99m}Tc$(3mCi)가 넣어져 있는 liver phantom을 콜리메타의 표면(表面)에 밀착(密着)시켜 다음과 같은 방법(方法)에 의하여 촬상(撮像)하였다. 즉, 일정(一定)한 상(像)의 농도(濃度)을 얻을 수 있는 촬상조건(撮像條件)을 찾아낼 목적(目的)으로 preset time, image size, 콜리메타전면(前面)- phantom간(間) 거리(距離), 그리고 window를 각각(各各) 변화(變化)시키면서 phantom을 촬상(撮像)하였으며, 특(特)히 거리(距離)와 window에 있어서는 cold defects의 검출능(檢出能)도 비교검토(比較檢討)하였다. 실험결과(實驗結果)는 다음과 같다. 1. C type film에 있어서 1.5의 농도(濃度)을 얻기위해서는 7.5의 intensity 에서 preset time은 60초(秒), image size는 1.0, 콜리메타-phantom간거리(間距離)는 0cm 그리고 window는 20%가 요구(要求)되고 있었다. 2. 편면유제(片面乳劑) film의 preset time은 양면유제(兩面乳劑) film보다 짧은 것으로 나타났다. 3. 상(像)의 분해능(分解能)은 image size가 작을수록, 콜리메타-phantom간(間) 거리(距離)가 짧을수록, 그리고 window 폭(幅)이 좁을수록 더욱 더 향상(向上)되고 있었다. 4. Cold defects의 검출능(檢出能)은 image size가 작을수록, 콜리메타-pantom간(間) 거리(距離)가 짧을수록, 그리고 window폭(幅)이 좁을수록 향상(向上)되고 있었다.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.2
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• pp.61-66
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• 2007

This study was to analysis the values for anterior and posterior Best-Fit Sphere(BFS) in a Korean emmetropic population using the Orbscan II system. Cycloplegic refraction and anterior and posterior BFS were performed 40 eyes of 20 patients and we compared the results by sex and between the two eyes. Respectively, the 1, 3, 5mm zone average of anterior BFS showed each $5.63{\pm}3.49{\mu}m$, $4.48{\pm}2.81{\mu}m$ and $2.14{\pm}1.82{\mu}m$. The 1, 3, 5mm zone average of posterior BFS showed each $22.54{\pm}10.25{\mu}m$, $15.88{\pm}7.55{\mu}m$ and $4.43{\pm}4.94{\mu}m$ in 40 emmetropic eyes. Anterior and posterior BFS were not statistically significant difference in male and female using Mann-Witney U test.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.207-213
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• 2016

In this study, a thermal flow analysis was performed using the commercial code, ANSYS-FLUENT to reduce room temperature in a turbine building of power plant. The selected control volume of the operating floor and deaerator floor for the turbine building was respectively modelled. The skylight windows at the deaerator floor were employed for ventilation windows. Through the study, in the first we found that all window close of the deaerator floor is one alternative for reducing the temperature of the operating floor. The next thing we knew that for windows open at the front of the deaerator floor, the temperature of deaerator zone and crane zone can be respectively reduced to $1.5^{\circ}C$ and $1.6^{\circ}C$. In addition, for windows close at the rear of the deaerator floor, the temperature of deaerator zone and crane zone can be respectively reduced to 1.4 and $0.5^{\circ}C$. Therefore, it was concluded that a better choice is to open the front windows at deaerator floor to reduce the temperature of the entire deaerator floor having high temperature.