• The Korean Journal of Nuclear Medicine Technology
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• v.25 no.2
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• pp.35-40
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• 2021

Purpose Glomerular filtration rate(GFR) is an important indicator for the diagnosis, treatment, and follow-up of kidney disease and is also used by healthy individuals for drug use and evaluating kidney function in donors. The gold standard method of the GFR test is to measure by continuously injecting the inulin which is extrinsic marker, but it takes a long time and the test method is complicated. so, the method of measuring the serum concentration of creatinine is used. Estimated glomerular filtration rate (eGFR) is used instead. However, creatinine is known to be affected by age, gender, muscle mass, etc. eGFR formulas that are currently used include the Cockroft-Gault formula, the modification of diet in renal disease (MDRD) formula, and the chronic kidney disease epidemilogy collaboration (CKD-EPI) formula for adults. For children, the Schwartz formula is used. Measurement of GFR using ⁵¹Cr-EDTA (diethylenetriamine tetraacetic acid), ^99mTc-DTPA (diethylenetriamine pentaacetic acid) can replace inulin and is currently in use. Therefore, We compared the GFR measured using ^99mTc-DTPA with the eGFR using CKD-EPI formula. Materials and Methods For 200 kidney transplant donors who visited Asan medical center.(96 males, 104 females, 47.3 years ± 12.7 years old) GFR was measured using plasma(Two-plasma-sample-method, TPSM) obtained by intravenous administration of ^99mTc-DTPA(0.5mCi, 18.5 MBq). eGFR was derived using CKD-EPI formula based on serum creatinine concentration. Results GFR average measured using ^99mTc-DTPA for 200 kidney transplant donors is 97.27±19.46(ml/min/1.73m²), and the eGFR average value using the CKD-EPI formula is 96.84±17.74(ml/min/1.73m²), The concentration of serum creatinine is 0.84±0.39(mg/dL). Regression formula of ^99mTc-DTPA GFR for serum creatinine-based eGFR was Y = 0.5073X + 48.186, and the correlation coefficient was 0.698 (P<0.01). Difference (%) was 1.52±18.28. Conclusion The correlation coefficient between the ^99mTc-DTPA and the eGFR derived on serum creatinine concentration was confirmed to be moderate. This is estimated that eGFR is affected by external factors such as age, gender, and muscle mass and use of formulas made for kidney disease patients. By using ^99mTc-DTPA, we can provide reliable GFR results, which is used for diagnosis, treatment and observation of kidney disease, and kidney evaluation of kidney transplant patients.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.77-82
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• 2010

Purpose: As PET/CT come into wide use, it caused increasing of expose in clinical use. Therefore, Korea Food and Drug Administration issued Patient DRL (Diagnostic Reference Level) in CT scan. In this study, to build the basis of patient dose reduction, we analyzed effective dose in transmission scan with CT scan. Materials and Methods: From February, 2010 to March 180 patients (age: $55{\pm}16$, weight: $61.0{\pm}10.4$ kg) who examined $^{18}F$-FDG PET/CT in Asan Medical Center. Biograph Truepoint 40 (SIEMENS, GERMANY), Biograph Sensation 16 (SIEMENS, GERMANY) and Discovery STe8 (GE healthcare, USA) were used in this study. Per each male and female average of 30 patients doses were analyzed by one. Automatic exposure control system for controlling the dose can affect the largest by a patient's body weight less than 50 kg, 50-60 kg less, 60 kg more than the average of the three groups were divided doses. We compared that measured value of CT-expo v1.7 and ImPACT v1.0. The relationship between body weight and the effective dose were analyzed. Results: When using CT-Expo V1.7, effective dose with BIO40, BIO16 and DSTe8 respectably were $6.46{\pm}1.18$ mSv, $9.36{\pm}1.96 $mSv and $9.36{\pm}1.96$ mSv for 30 male patients respectably $6.29{\pm}0.97$ mSv, $10.02{\pm}2.42$ mSv and $9.05{\pm}2.27$ mSv for 30 female patients respectably. When using ImPACT v1.0, effective dose with BIO40, BIO16 and DSTe8 respectably were $6.54{\pm}1.21$ mSv, $8.36{\pm}1.69$ mSv and $9.74{\pm}2.55$Sv for 30 male patients respectably $5.87{\pm}1.09$ mSv, $8.43{\pm}1.89$ mSv and $9.19{\pm}2.29$ mSv for female patients respectably. When divided three groups which were under 50 kg, 50~60 kg and over 60 kg respectably were 6.27 mSv, 7.67 mSv and 9.33 mSv respectably using CT-Expo V1.7, 5.62 mSv, 7.22 mSv and 8.91 mSv respectably using ImPACT v1.0. Weight and the effective dose coefficient analysis showed a very strong positive correlation(r=743, r=0.693). Conclusion: Using such a dose evaluation programs, easier to predict and evaluate the effective dose possible without performing phantom study and such dose evaluation programs could be used to collect basic data for CT dose management.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.97-106
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• 2015

Purpose : This study evaluate the thermal changes caused by use of the chemoport for drug administration and blood sampling during radiofrequency hyperthermia. Materials and Methods : 20cm size of the electrode radio frequency hyperthermia (EHY-2000, Oncotherm KFT, Hungary) was used. The materials of the chemoport in our hospital from currently being used therapy are plastics, metal-containing epoxy and titanium that were made of the diameter 20 cm, height 20 cm insertion of the self-made cylindrical Agar phantom to measure the temperature. Thermoscope(TM-100, Oncotherm Kft, Hungary) and Sim4Life (Ver2.0, Zurich, Switzerland) was compared to the actual measured temperature. Each of the electrode measurement position is the central axis and the central axis side 1.5 cm, 0 cm(surface), 0.5 cm, 1.8 cm, 2.8 cm in depth was respectively measured. The measured temperature is $24.5{\sim}25.5^{\circ}C$, humidity is 30% ~ 32%. In five-minute intervals to measure the output power of 100W, 60 min. Results : In the electrode central axis 2.8 cm depth, the maximum temperature of the case with the unused of the chemoport, plastic, epoxy and titanium were respectively $39.51^{\circ}C$, $39.11^{\circ}C$, $38.81^{\circ}C$, $40.64^{\circ}C$, simulated experimental data were $42.20^{\circ}C$, $41.50^{\circ}C$, $40.70^{\circ}C$, $42.50^{\circ}C$. And in the central axis electrode side 1.5 cm depth 2.8 cm, mesured data were $39.37^{\circ}C$, $39.32^{\circ}C$, $39.20^{\circ}C$, $39.46^{\circ}C$, the simulated experimental data were $42.00^{\circ}C$, $41.80^{\circ}C$, $41.20^{\circ}C$, $42.30^{\circ}C$. Conclusion : The thermal variations were caused by radiofrequency electromagnetic field surrounding the chemoport showed lower than in the case of unused in non-conductive plastic material and epoxy material, the titanum chemoport that made of conductor materials showed a slight differences. This is due to the metal contents in the chemoport and the geometry of the chemoport. And because it uses a low radio frequency bandwidth of the used equipment. That is, although use of the chemoport in this study do not significantly affect the surrounding tissue. That is, because the thermal change is insignificant, it is suggested that the hazard of the chemoport used in this study doesn't need to be considered.

• Progress in Medical Physics
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• v.26 no.3
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• pp.160-167
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• 2015

Radiation exposure from medical diagnostic imaging procedures to patients is one of the most significant interests in diagnostic x-ray system. A miniature x-ray intraoral tube was developed for the first time in the world which can be inserted into the mouth for imaging. Dose evaluation should be carried out in order to utilize such an imaging device for clinical use. In this study, dose evaluation of the new x-ray unit was performed by 1) using a custom made in vivo Pig phantom, 2) determining exposure condition for the clinical use, and 3) measuring patient dose of the new system. On the basis of DRLs (Diagnostic Reference Level) recommended by KDFA (Korea Food & Drug Administration), the ESD (Entrance Skin Dose) and DAP (Dose Area Product) measurements for the new x-ray imaging device were designed and measured. The maximum voltage and current of the x-ray tubes used in this study were 55 kVp, and 300 mA. The active area of the detector was $72{\times}72mm$ with pixel size of $48{\mu}m$. To obtain the operating condition of the new system, pig jaw phantom images showing major tooth-associated tissues, such as clown, pulp cavity were acquired at 1 frame/sec. Changing the beam currents 20 to $80{\mu}A$, x-ray images of 50 frames were obtained for one beam current with optimum x-ray exposure setting. Pig jaw phantom images were acquired from two commercial x-ray imaging units and compared to the new x-ray device: CS 2100, Carestream Dental LLC and EXARO, HIOSSEN, Inc. Their exposure conditions were 60 kV, 7 mA, and 60 kV, 2 mA, respectively. Comparing the new x-ray device and conventional x-ray imaging units, images of the new x-ray device around teeth and their neighboring tissues turn out to be better in spite of its small x-ray field size. ESD of the new x-ray device was measured 1.369 mGy on the beam condition for the best image quality, 0.051 mAs, which is much less than DRLs recommended by IAEA (International Atomic Energy Agency) and KDFA, both. Its dose distribution in the x-ray field size was observed to be uniform with standard deviation of 5~10 %. DAP of the new x-ray device was $82.4mGy*cm^2$ less than DRL established by KDFA even though its x-ray field size was small. This study shows that the new x-ray imaging device offers better in image quality and lower radiation dose compared to the conventional intraoral units. In additions, methods and know-how for studies in x-ray features could be accumulated from this work.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.16 no.2
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• pp.279-285
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• 2005

Objectives : This study was performed to evaluate the efficacy and safety of MPH-OROS and parental satisfaction for treatment of children with ADHD Method : The 569 participants were clinically diagnosed for ADHD using DSM-IV criteria. We switched current medication to MPH-OROS or introduced MPH-OROS for treatment of ADHD. We assessed the clinical global impression severity of illness (CGI-S), the clinical global impression severity of improvement(CGI-I). And the parents of participants measured the Korean version of Conners rating scale at baseline, the 1 st week and the 3rd week after MPH-OROS trial. At the 3rd week, the parents measured the parent satisfaction questionnaire. Results : $13\%$ of participants dropped out because of several causes including side effects. The change of CGI-S was significantly decreased. Using CGI-I, the improvement was $72.3\%$ at the 1st week and $87.4\%$ at the 3rd week. The total score of the Korean version of Conners parent rating scale was significantly decreased. The participants complaining one or more of side effects were 119$(20.7\%)$, and the most common side effect was anorexia. The $94\%$ of parents replied that they were overall satisfied with MPH-OROS trial. Also the advantages of MPH-OROS of parental report were the long duration of the drug, the improvement of schoolwork and attitude, the improvement of home behavior and homework and the improvement of overactivity. Conclusion : MPH-OROS is effective and well-tolerated in actual clinical use for ADHD.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.101-107
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• 2014

Community-acquired antimicrobial resistant bacteria are an emerging problem world-wide. In Korea, resistant bacteria are more prevalent than in other industrialized countries. The aim of this study was to investigate the isolation frequency of methicillin-resistant staphylococci (MRS), Pseudomonas, and Enterobacteriaceae from surrounding environment (home, colleges, public transportation system and possessions) in Seoul, and to examine the level of drug resistance to 13 antimicrobial agents, which are in wide spread clinical use in Korea, as well as new agent, tigecycline in Enterobacteriaceae isolates. Of total 239 samples, 18 (7.5%) MRS, 10 (4.2%) Pseudomonas, and 30 (12.6%) Entarobacteriaceae were isolated. A total of 5 (2.1%) methicillin-resistant S. aureus (MRSA) were detected in home (2 samples), colleges (1 sample), and et cetera (2 sample). A total of 5 (2.1%) Escherichia coli were detected in in home (1 samples), public transportations (3 sample), and et cetera (1 sample). Resistance to cephalosporins, fluoroquinolones, carbapenems, ${\beta}$-lactams, tetracyclines, and aminoglycosides was found in 71.9%, 71.9%, 68.8%, 68.8%, 50.0%, and 25.0% of 32 Enterobacteriaceae isolates, respectively. Also, resistance rate to trimethoprim/sulfamethoxazole of the isolates was a 43.8%. Moreover, 59.4% of the isolates were resistant to new agent, tigecycline and resistance to all agents tested was observed in 3 isolates. Five E. coli isolates were resistant to most of the agents tested, but some of them were susceptible to ciprofloxacin and gentamicin. This study can serve as a data point for future comparisons of possible changes in antibiotic resistance levels in surrounding environment. And multilateral strategies for preventing the incidence and spread of antibiotic resistance are needed.

• Child Health Nursing Research
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• v.20 no.3
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• pp.159-167
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• 2014

Purpose: The purpose of this study was to investigate factors associated with sexual debut among Korean middle school students. Methods: From the database of the Eighth Korea Youth Risk Behavior Web-based Survey (KYRBS), the researchers selected 37,297 middle school students aged 12-15 years. Data were analyzed using $x^2$ test and multiple logistic regression with the SPSS WIN 18.0 program. Results: The proportion of middle school students who had a sexual debut was 2.1% of boys and 1.5% of girls. In multiple regression analysis, economic status, experience of part time work, smoking, drug use and depression were associated with an increased proportion of sexual intercourse for both boys and girls. Living with parents, drinking alcohol and suicidal ideation were associated with sexual debut for boys only. By contrast, formal sexual education was associated with a reduced risk of sexual debut. Conclusion: The results of this study show the factors associated with sexual debut among Korean middle school students. Gender-related interventions should be taken into consideration in school sexual education programmes, because of differences in related factors according to gender.

• Korean Journal of Acupuncture
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• v.29 no.2
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• pp.179-187
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• 2012

Objectives : Since acupuncture was accepted as an useful therapy for the drug addiction, a lot of studies about acupuncture have been carried out. This study was performed to review the articles about morphine addiction which used acupuncture as a treatment and to interpret the use of acupoints from the viewpoint of Six-meridian (Yuk Gyeong, three yin and three yang) theory. Methods : The authors searched 255 articles in PubMed with the key word of "morphine, acupuncture" and 629 articles in KISS (Koreanstudies Information Service System) with the key word of "morphine". The articles written in English only were included. The articles related with morphine (abuse, dependence, sensitization, addiction, intake, withdrawal sign, withdrawal syndrome, reinstatement, craving) only were included. The articles which used manual- or electro-acupuncture only were included and auricular acupuncture was excluded. Both of clinical and experimental study were reivewed. Results : The most frequently used acupoint was ST36-SP6 (electroacupuncture), and the second was HT7. LI4 was the third, and BL23 and PC6 were also used. Conclusions : The acupoints used in the morphine study seem to influence the brain through diverse mechanisms and it is thought that control of the reaction against stress appears to be related with these mechanisms.

• Radiation Oncology Journal
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• v.28 no.1
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• pp.50-56
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• 2010

Purpose: We report the results of an external audit on the absorbed dose of radiotherapy beams independently performed by third parties. For this effort, we developed a method to measure the absorbed dose to water in an easy and convenient setup of solid water phantom. Materials and Methods: In 2008, 12 radiotherapy centers voluntarily participated in the external auditing program and 47 beams of X-ray and electron were independently calibrated by the third party’s American Association of Physicists in Medicine (AAPM) task group (TG)-51 protocol. Even though the AAPM TG-51 protocol recommended the use of water, water as a phantom has a few disadvantages, especially in a busy clinic. Instead, we used solid water phantom due to its reproducibility and convenience in terms of setup and transport. Dose conversion factors between solid water and water were determined for photon and electron beams of various energies by using a scaling method and experimental measurements. Results: Most of the beams (74%) were within ${\pm}2%$ of the deviation from the third party's protocol. However, two of 20 X-ray beams and three of 27 electron beams were out of the tolerance (${\pm}3%$), including two beams with a >10% deviation. X-ray beams of higher than 6 MV had no conversion factors, while a 6 MV absorbed dose to a solid water phantom was 0.4% less than the dose to water. The electron dose conversion factors between the solid water phantom and water were determined: The higher the electron energy, the less is the conversion factor. The total uncertainty of the TG-51 protocol measurement using a solid water phantom was determined to be ${\pm}1.5%$. Conclusion: The developed method was successfully applied for the external auditing program, which could be evolved into a credential program of multi-institutional clinical trials. This dosimetry saved time for measuring doses as well as decreased the uncertainty of measurement possibly resulting from the reference setup in water.

• The Korean Journal of Nuclear Medicine
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• v.32 no.5
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• pp.403-413
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• 1998

Purpose: We investigated reproducibility of the quantification of left ventricular volume and ejection fraction, and grading of myocardial wall motion and systolic thickening when we used gated myocardial SPECT and Cedars quantification software. Materials and Methods: We performed gated myocardial SPECT in 33 consecutive patients twice in the same position after Tc-99m-MIBI SPECT We used 16 frames per cycle for the gating of sequential Tc-99m-MIBI SPECT. After reconstruction, we used Cedars quantitative gated SPECT and calculated ventricular volume and ejection fraction (EF). Wall motion was graded using 5 point score. Wall thickening was graded using 4 point score. Coefficient of variation for re-examination of volume and fraction were calculated. Kappa values (k-value) for assessing reproducibility of wall motion or wall thickening were calculated. Results: Enddiastolic volumes (EDV) ranged from 58 ml to 248 ml (122 ml +/- 42 ml), endsystolic volumes (ESV) from 20 ml to 174 ml (65 ml +/- 39 ml), and EF from 20% to 65% (51% +/- 14%). Geometric mean of standard deviations of 33 patients was 5.0 ml for EDV, 3.9 ml for ESV and 1.9% for EF. Their average differences were not different from zero (p>0.05). k-value for wall motion using 2 consecutive images was 0.76 (confidence interval: 0.71-0.81). k-value was 0.87 (confidence interval: 0.83-0.90) for assessment of wall thickening. Conclusion: We concluded that quantification of functional indices, assessment of wall motion and wall thickening using gated Tc-99m-MIBI SPECT was reproducible and we could use this method for the evaluation of short-acting drug effect.