• 핵의학기술
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• 제17권2호
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• pp.72-77
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• 2013

Purpose: Whole-body PET using radiopharmaceutical is one of the imaging study methods for physiological changes of body. High specificity of the PET-CT examination is used to detect an early stages of cancer and metastatic cancer by imaging a physiological changes. During the imaging process, PET image has been characterized by a relatively low image quality due to its low sensitivity and the acquisition of random and scatter coincidences as well as patients figure. Therefore, the image quality as the changes of the acquisition times of patient weight was evaluated in this study. Materials and Methods: Thirty patients who presented to our hospital were enrolled. They were divided to normal, overweight, and obese group using BMI index, respectively. The patients with a liver disease and diabetes were excluded. $^{18}F-FDG$ was administered to the patients as 5.2 MBq per kg. After an hour from an injection, image acquisition was obtained as List mode in a part of liver in 1 bed. SNR (signal-to-noise ratio) of each groups acquisition times were confirmed from the calculated radiation counts and random fractions. The statistical significance of three groups was confirmed through one-way ANOVA test. On the basis of the counts of 2 minutes on normal group, the SNR of overweight group and obese group were compared. Results: The SNR were increased with loger aquisition time in 3 groups. In the condition of same acquisition time, the SNR had a statistical significance (P<0.05). The SNR were decreased to the normal, overweight, and obese, respectively. Liver activity had no significance difference on each group and RF had the significance differences (P<0.05). On the basis of the counts of 2 minutes on normal group, there were no statistical significance in a three minute acquisitions of overweight group and two minute acquisitions of obese group (P=0.150). Conclusion: In this study, the administrated amount of radiation dose did not adjust as the change of the patients weight. Increasing the acquisition time when the administration of the same amount of dose was able to get a good result of SNR. When the Based 2 minute on normal group, if overweight and obese case the increased acquisition time of 3 minute was able to obtain a similar SNR. On the basis of the normal group, the acquisition times of overweight and obese group were increased to 3 minutes per bed and the SNR were similar to the normal group.

• 대한방사성의약품학회지
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• 제3권1호
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• pp.38-43
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• 2017

Tc-99m labeled sestamibi ($^{99m}Tc$-MIBI) is one of most widely used radiopharmaceuticals for myocardial SPECT imaging. Radiolabeling of $^{99m}Tc$-MIBI is recommended by heating in $100^{\circ}C$ water bath for 15 min. However, the water bath might be a source of contamination. Thus, if radiolabeling of $^{99m}Tc$-sestamibi can be performed at room temperature, then it would be more convenient to use in clinical application. In this study, we performed the radiolabeling of $^{99m}Tc$-MIBI in different temperature conditions or using different instruments to find out the efficient labeling condition. We studied the $^{99m}Tc$-MIBI labeling at room temperature or $100^{\circ}C$ heating block, and checked the labelling yields every 1 min for 10 min using radio-TLC with 2 different eluents-saline and acetone. From the experiment, we confirmed that the $^{99m}Tc$-MIBI can be labeled over 90% yield but not completed at room temperature. However, the $^{99m}Tc$-MIBI labeling was completed when it was performed in the $100^{\circ}C$ heating block. Finally, we proved that heating is essential for complete $^{99m}Tc$-MIBI labelling, furthermore using heating block is also possible instead of water bath.

• 대한핵의학회지
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• 제29권1호
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• pp.48-53
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• 1995

Rb-82 dynamic PET과 이중적분법에 의한 국소 심근 혈류측정 연구를 시행하고자 실험 개를 이용한 심근 혈전증 모델에서 좌심실 입력함수에 의한 정상 및 관류결손 심근에서의 혈류를 측정하였다. 이중적분법이 선형회귀모델에 의한 혈류측정방법에 비하여 실현이 간단하고 심근내 혈류가 선형적인 가정을 배제할 수 있어 더욱 정확한 방법이 될 수 있음을 확인하였다.

• 핵의학기술
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• 제22권1호
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• pp.76-79
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• 2018

Purpose Carcinoembryonic antigen (CEA) is cell-surface 180-200 kDa glycoprotein that is overexpressed in breast, stomach pancreas, lung, and colorectal cancers. CEA was first described in 1965 by Gold and Freedman and then serum CEA of colorectal cancer patients was first measured in 1969 by radioimmunoassay by Thomson. CEA is currently most widely used tumor marker in the clinic for management of colorectal cancer. Various CEA test kits have been developed and commercialized. CEA kits from different manufacturers might have different test results because of different reagents and protocol. The purpose of this study was to compare results of four commercial available CEA kits. Materials and Methods This study was designed to evaluate four commercially available CEA kits using serum samples acquired from 120 patients who visited our clinic. Test results were compared and analyzed according to the respective test methods. High concentration samples were diluted with saline and diluted solution. Results All of the four kits showed a significant correlation within the reference value. However, three of the four kits used for the dilution test using high concentration samples showed the hook effect. Conclusion Results of the present study showed that It is important to establish the standardized dilution standards for the high-concentration specimens to manage the error of the test result by the hook effect.

• 핵의학기술
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• 제13권3호
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• pp.193-195
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• 2009

Purpose: The work flow of international hospital's laboratory consists of rapid test and result report at the present day. However, the frequent inquiry of sample, which cause affairs to delay and efficiency to Lower, affects medical examination. In order to promote work's efficiency, we should improve the problem and make work smooth between a laboratory, outs and ward. Materials and Methods: This study runs as follows. First, Investigating test result, test schedule, test receipt, quick result, etc through the activity required from September to November 2007 about the inquiry of sample. After analysis of the problem in December, remaking the test schedule for improvement solution and reporting it to outs and ward. When the result is retest and dilution, we directly fill in a result space with the result situation of the patient to let them know beforehand. We also, prevent the omission of the result through checking the sample list and discriminate in vivo from in vitro by changing the laboratory's telephone number. We have improved the problem about the inquiry of sample through valuation and analysis since the improvement activity from January to March 2008. Result: The case about the frequent inquiry of sample has reduced by 57.8%. this improvement activity indicated that p-value<0.05 was statistically significant through paired t-test. This activity make study smooth and we rapidly report the result. Conclusion: By reducing the case regarding the inquiry of sample, work discontinuation, and concentration reduction, the work efficiency was increased.

• 핵의학기술
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• 제21권1호
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• pp.29-33
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• 2017

QA 과정을 통해 30개의 정규화 보정값을 얻고, 1개의 기준 데이터 설정 후 29개의 정규화 보정값과 비교하였다. 또한 각 정규화 보정값을 PET raw data 에 적용시켜 재구성된 영상을 동일한 ROI를 그려 SUV 와 count 로 비교평가 하였다. 30개의 정규화 보정값은 차이가 발생하지 않았으며, 각각의 정규화 보정값을 적용시킨 PET 영상도 크게 차이가 없었다. 핵의학 영상은 정량분석을 위해 불감시간 보정 및 광자의 감쇠 및 산란 등 물리적 현상에 대한 보정이 필요하고, 정규화 보정 또한 무시할 수 없는 보정 과정이다. 따라서 이런 과정을 통해 PET 장비의 균일성이 유지되고 여러 디텍터의 효율도 균등해야 영상의 왜곡을 방지할 수 있고, 질 좋은 영상을 만드는데 꼭 필요한 과정이므로 매일 QA 과정이 필요하다고 사료된다.

• Nuclear Medicine and Molecular Imaging
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• 제40권1호
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• pp.51-52
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• 2006

A 39-year-old female patient who had undergone a total thyroidectomy for a papillary thyroid carcinoma underwent a whole body scan with I-131. The I-131 scan was performed 72 hours after administering 185 MBq (5 mCi) of an I-131 solution. The anterior image of the head, neck, and upper chest showed multiple areas of increased uptake in the mediastinal area considering of functional metastasis. However, radioactivity was not evident in the image taken after removing her clothes and muffler. The image obtained after placing the muffler on the pallet showed that the radioactivity was still present. It is well known that artifacts on an I-131 scan can be produced by styling hair sputum, drooling during sleep, chewing gum, and paper or a cloth handkerchief that is contaminated with the radioactive iodine from either perspiration or saliva. This activity might be mistaken for a functional metastasis. Therefore, it is essential that an image be obtained after removing the patient's clothes. In this study, artifacts due to a contaminated muffler on the I-131 scan were found. These mimicked a functional metastasis of the mediastinal area in a patient with a papillary thyroid carcinoma.

• 핵의학기술
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• 제13권1호
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• pp.98-103
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• 2009

Purpose: Correct estimation of Glomerular filtration rate (GFR) is very important for an accurate clinical assessment of the kidney function. This study compares four GFR markers, a serum creatinine-based estimation using MDRD formula, Cystatin-C, Cr-51 EDTA 2 samples and 6 samples. Materials and Methods: Serum creatinine concentrations, Cystatin-C serum concentrations and Cr-51 EDTA clearance are measured in 43 patients who received or donated kidney. Results: The correlation coefficient between serum based estimated GFR (MDRD) and Cr-51 EDTA 6 samples was 0.817 (p<0.01). The correlation coefficient between Cystatin-C based GFR and EDTA 6 samples was 0.7322 (p<0.01). Regression analysis showed a statistically significant correlation between Cr-51 EDTA 2 samples and 6 samples (r=0.971, p<0.01). Mean value and ${\pm}2SD$ for the difference between Cr-51 EDTA 2 samples and 6 samples were 4.7 mL/min and ${\pm}9.3$ respectively. Conclusions: The estimation of two samples Cr-51 EDTA showed that the method can be simplified by reducing blood samples without losing its high accuracy.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.303-304
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• 1998

We investigated the effects of scintillation crystal surface treatment on gamma camera imaging. The NaI(Tl) and CsI(Tl) (20 mm (dia.) $\times10mm$ (thick) plate) scintillators were chosen for this study. Two different surface treatments, white and black reflectors, were applied to NaI(Tl) and CsI(Tl). The optical properties of generated scintillation light were evaluated using Monte Carlo simulation and postion sensitive photo multiplier tube (PSPMT). We measured sensitivity, energy resolution and spatial resolution of a gamma camera system with the scintillators coupled to a PSPMT. Based on the results, we concluded that the careful consideration of surface treatments of the scintillator was necessary in order to develop the gamma camera having good sensitivity and spatial resolution.

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3352-3358
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• 2023

Nuclear medicine seems to be a decent choice of medicine in the recent decade. The radioactive isotopes ⁵¹Cr, ⁸⁹Sr, ⁹⁹Tc, ¹³¹I, ¹³³Xe, ¹³⁷Cs and ¹⁵³Sm are extremely essential in nuclear medicine. The excitation functions of the ⁵⁴Fe (n, α) ⁵¹Cr, ⁹²Zr (n, α) ⁸⁹Sr, ¹⁰²Rh (n, α) ⁹⁹Tc, 134Cs (n, α) ¹³¹I, ¹³⁶Ba (n, α) ¹³³Xe, ¹⁴⁰La (n, α) ¹³⁷Cs and ¹⁵⁶Gd (n, α) ¹⁵³Sm reactions were calculated in this study using the EMPIRE 3.2.3 and TALYS 1.95 nuclear codes. Additionally, the cross sections at 14-15 MeV were calculated using empirical formulae and the experimental data. The computer codes were compared to the experimental data and Empirical formulas as well as the evaluated data (TENDL 2021, JENDL 3.3, JENDL 5, JEFF 3.3, EAF 2010, CENDL 3.1, CENDL 3.2, ROSFOND 2010, FENDL 3.2 b, and BROND 3.1).