• Journal of The Korean Society of Inherited Metabolic disease
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• v.16 no.1
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• pp.18-23
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• 2016

Objective: Newborn screening leads to improved treatment and disease outcomes, but false-positive newborn screening results may impact include parental stress and anxiety, perception of child as unhealthy, parent-child relationship dysfunction, and increased infant hospitalizations. The purpose of this study was to investigate of the false positive rates and the causative factors of false positive results in Tandem Mass Spectrometry (TMS) in single center. Methods: Records were reviewed for all 18,872 subjects who were born in Cheill General Hospital, during January 1st, 2012 to December 31st, 2014. 17,292 neonates (91.62%) were tested for tandem mass screening almost in 2-5th day of life. Newborn babies whose first results were abnormal had been tested repeatedly by same methods in 7-14 day. If the results were abnormal again, further evaluation was performed. TMS analysis included data for the 43 disorders screened for using TMS broken down into three categories: fatty acid oxidation disorders, organic acidurias, and aminoacidopathies. The impact of several factors on increased false positive rates was analyzed using a multivariate analysis: time from birth to sample collection, birth weight, birth height, BMI, gender, gestational age, delivery type. Results: Males of the subjects were 8942 (51.7%), female 8350 (48.3%), the mean gestational age was $38.6{\pm}1.7$ weeks, the average birth weight $3,155.6{\pm}502.4g$, the average birth height $49.1{\pm}2.9cm$, and the average BMI $13.0{\pm}3.8(kg/m^2)$. Vaginal delivery cases were 9713 (56.2%), caesarean section 7,579 (43.8%). The average date of the inspection was $2.8{\pm}1.1$ days. 224 cases were identified as TMS positive. All the subjects were false positive (222/17,292, 1.30%) except 2 cases (1 male; benign phenylketonuria and 1 female; Short chain acyl-CoA dehydrogenase deficiency). The false positive rates were 0.61% in fatty acid oxidation disorders, 0.25% in organic acidurias, and 0.45% in aminoacidopathies. In our study, the date of inspection got late, the false positive rates got higher. Because almost the cases of late test date were in treatment in neonatal intensive care unit so their test date was affected by their medical conditions. False positive rate was higher in extreme immaturity${\leq}27$ weeks than newborns of gestational age >27 weeks [OR=6.957 (CI=1.273-38.008), p<0.025] and extremely low birth weight<1,000 g than newborns of birthweight ${\geq}1,000g$ [OR=5.616 (CI=1.134-27.820), p<0.035]. Conclusion: False positive rate of TMS was 1.30% in Cheil General Hospital. Lower gestational age and birth weight impacted on increased false positive rates. Better understanding of factors that influence the reporting of screening tests, and the ability to modify these important factors, may improve the screening process and reduce the need for retesting. of screening tests, and the ability to modify these important factors, may improve the screening process and reduce the need for retesting.

• Journal of radiological science and technology
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• v.32 no.4
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• pp.361-370
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• 2009

The image quality management of bone mineral density is the responsibility and duty of radiologists who carry out examinations. However, inaccurate conclusions due to lack of understanding and ignorance regarding the methodology of image quality management can be a fatal error to the patient. Therefore, objective of this paper is to understand proper image quality management and enumerate methods for examiners and patients, thereby ensuring the reliability of bone mineral density exams. The accuracy and precision of bone mineral density measurements must be at the highest level so that actual biological changes can be detected with even slight changes in bone mineral density. Accuracy and precision should be continuously preserved for image quality of machines. Those factors will contribute to ensure the reliability in bone mineral density exams. Proper equipment management or control methods are set with correcting equipment each morning and after image quality management, a phantom, recommended from the manufacturer, is used for ten to twenty-five measurements in search of a mean value with a permissible range of ${\pm}1.5%$ set as standard. There needs to be daily measurement inspections on the phantom or at least inspections three times a week in order to confirm the existence or nonexistence of changes in values in actual bone mineral density. in addition, bone mineral density measurements were evaluated and recorded following the rules of Shewhart control chart. This type of management has to be conducted for the installation and movement of equipment. For the management methods of inspectors, evaluation of the measurement precision was conducted by testing the reproducibility of the exact same figures without any real biological changes occurring during reinspection. Bone mineral density inspection was applied as the measurement method for patients either taking two measurements thirty times or three measurements fifteen times. An important point when taking measurements was after a measurement whether it was the second or third examination, it was required to descend from the table and then reascend. With a 95% confidence level, the precision error produced from the measurement bone mineral figures came to 2.77 times the minimum of the biological bone mineral density change. The value produced can be stated as the least significant change (LSC) and in the case the value is greater, it can be stated as a section of genuine biological change. From the initial inspection to equipment moving and shifter, management must be carried out and continued in order to achieve the effects. The enforcement of proper quality control of radiologists performing bone mineral density inspections which brings about the durability extensions of equipment and accurate results of calculations will help the assurance of reliable inspections.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.149-155
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• 2012

Purpose : Serum insulin levels are useful indicator which of reflecting the function of insulin secretion in pancreatic ${\beta}$ cell and diagnosis of diabetes, differentiating the cause of impaired glucose tolerance. Insulin measurement kits have shown some differences in many ways such as test methods as well as quality control. The purpose of this study was to evaluate the diagnostic performance of seven manufacturing companies commercial kits. Materials and Methods : The values of insulin measured by three manufacturing companies (Biosource, Siemens, TFB) with 59 samples in August 2009 were compared with those measured by four manufacturing companies (Immunotech, Izotope, BNIBT, Cisbio) with 68 samples in December 2011. We evaluated precision, recovery rate, dilution test and correlation of serum insulin measurement using seven manufacturing company kits. Statistical program SPSS 12.0 was used for the verification of results. Results : The coefficients variation of the precision on all seven different kits were showed within 5.0%. Recovery rate of Biosource, Siemens, TFB kits on three different levels showed 94.2~103.7%, 99.0~104.6%, 99.7~107.6% respectively. Immunotech, Izotope, BNIBT, Cisbio were 93.5~99.1%, 91.4~99.1%, 99.2~131.0%, 84.8~102.3% respectively. There was strong correlation between the measurement of insulin by Biosource kit and that by two commercial kits, Siemens (R2=0.96), TFB (R2=0.99). There was good correlation between the measurement of insulin by TFB kit and that by three commercial kits, Immunotech (R2=0.97), Izotope (R2=0.96), Cisbio (R2=0.97). In the dilution test performed with more than 200 ${\mu}IU/ml$ high concentration samples, samples with diabetes correctly was measured in all seven manufacturing kits. However, as measured with insulinoma samples TFB, Siemens, Izotope, Cisbio kits were correctly measured, but Biosource and Immunotech kits were measured 47.4 ${\mu}IU/ml$, 72.3 ${\mu}IU/ml$, respectively. Conclusion : Serum Insulin radioimmunoassay kits were showed excellent precision, correlation and good recovery rate. However, some kits were not measured correctly in the high concentration insulin values. when selecting a kit should be considered many factors that cost effectiveness, compatible for automation equipment, high performance kit, the environment for each laboratory such as reaction time and reporting time.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.12-17
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• 2012

Purpose : The patient's clothes and sheet after radioiodine therapy must be disposed of by related regulation. That must be disposed of as radioactive wastes, but that is reusing after radioactivity decay by keeping for the certain period of time. In general, The minimum storage period calculate by standard of take radioactive substance out of radiation controlled area based on measured surface contamination level. But the measurements of surface contamination level are able to differ by measurement method. In this paper, I wish to calculate the minimum storage period of patient's clothes and sheet after radioiodine therapy by measure nuclide concentration offered by the regulation on self-disposal of radioactive wastes. Materials and Methods : The whole area of patient's clothes and sheet measured 31 patients(male:9 patients, female:22 patients), who had radioiodine therapy(3.7 GBq:13 patients, 5.55 GBq:16 patients, 7.4 GBq:2 patients) from july 2011 to march 2012. The minimum storage period is calculated by the regulation on self-disposal of radioactive waste(100 Bq/g) and standard of take radioactive substance out of radiation controlled area(4 kBq/m2) Results : The minimum storage period of pillow sheet, upper uniform, lower uniform by standard of take radioactive substance out of radiation controlled area were each 4.6 days, 63days, 78 days. The minimum storage period of pillow sheet, upper uniform, lower uniform by the regulation on self-disposal of radioactive waste were each 18.1 days, 43 days, 62 days. Conclusion : We can verify that patient's clothes and sheet after radioiodine therapy exists a great deal of radioactive contamination. The minimum storage period calculation of patient's clothes and sheet is better suited to applying nuclide concentration offered by the regulation on self-disposal of radioactive waste. I recommend, To keep for at least 2 months of the patient's clothes and sheet contaminated radioactivity, for prevent contamination and unnecessary radiation exposure.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.127-132
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• 2010

Purpose: Because of limitation of image acquisition method and acquisition time, scatter correction cannot perform easily in SPECT study. But in our hospital, could provide to clinic doctor of scatter corrected images, through introduction of new generation gamma camera has function of simple scatter correction. Taking this opportunity, we will compare scatter corrected and non-scatter corrected image from image quality of point of view. Materials and Methods: We acquisite the 'Hoffman brain phantom' SPECT image and '1mm line phantom' SPECT image, each 18 times, with GE Infinia Hawkeye 4, SPECT-CT gamma camera. At first, we calculated each contrast from axial slice of scatter corrected and non-scatter corrected SPECT image of 'Hoffman brain phantom'. and next, calculated each FWHM of horizontal and vertical from axial slice of scatter corrected and non-scatter corrected SPECT image of '1mm line phantom'. After then, we attempted T test analysis with SAS program on data, contrast and resolution value of scatter corrected and non-scatter corrected image. Results: The contrast of scatter corrected image, elevated from 0.3979 to 0.3509. And the resolution of scatter corrected image, elevated from 3.4822 to 3.6375. p value were 0.0097 in contrast and <0.0001 in resolution. We knew the fact that do improve of contrast and resolution through scatter correction. Conclusion: We got the improved SPECT image through simple and easy way, scatter correct. We will expect to provide improved images, from contrast and resolution point of view. to our clinic doctor.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.35-39
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• 2010

Purpose: The aim of this study was to investigate distribution of particle size in phytate kit and compare filtered method with non-filtered method using 200 nm filter for sentinel lymphoscintigraphy (SLS). Materials and Methods: Five phytate kit of having the same available period was measured by particle size analyzer. For in-vivo experiment, $^{99m}Tc$-phytate was injected intradermally at both foot to perform lymphoscintigraphy. Imaging was acquired at 1hour after injection. Region of interest (ROI) was drawn in inguinal and background area for analysis. RAW 264.7 cells (Murine macrophage cell) were prepared for measurement of celluar uptake as a representative of macrophages. Paired t-test was performed using SPSS (SPSS Inc, USA) for statistical analysis. Results: The size of most particle in Techne phytate kit was distributed in 130~650 nm(90.5 %). In-vivo study, the ROI analysis showed similar result between filtered and non-filtered sample, and the numerical value of count/pixel were $58.3{\pm}5.97$ and $60.2{\pm}4.88$. In-vitro study, cellular uptake study also showed no difference between filtered and non-filtered sample by gamma counting. Conclusion: The present study demonstrates that there was no meaning of 200 nm filtered method for SLS using $^{99m}Tc$-phytate.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.111-114
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• 2010

Purpose: There has been recent interest in the radioactivity uptake and image acquisition of radioactivity concentration. The degree of uptake is strongly affected by many factors containing $^{18}F$-FDG injection volume, tumor size and the density of blood glucose. Therefore, we investigated how radioactivity uptake in target influences 2D or 3D image analysis and elucidate radioactivity concentration that mediate this effect. This study will show the relationship between the radioactivity uptake and 2D,3D image acquisition on radioactivity concentration. Materials and Methods: We got image with 2D and 3D using 1994 NEMA PET phantom and GE Discovery(GE, U.S.A) STe 16 PET/CT setting the ratio of background and hot sphere's radioactivity concentration as being a standard of 1:2, 1:4, 1:8, 1:10, 1:20, and 1:30 respectively. And we set 10 minutes for CT attenuation correction and acquisition time. For the reconstruction method, we applied iteration method with twice of the iterative and twenty times subset to both 2D and 3D respectively. For analyzing the images, We set the same ROI at the center of hot sphere and the background radioactivity. We measured the radioactivity count of each part of hot sphere and background, and it was comparative analyzed. Results: The ratio of hot sphere's radioactivity density and the background radioactivity with setting ROI was 1:1.93, 1:3.86, 1:7.79, 1:8.04, 1:18.72, and 1:26.90 in 2D, and 1:1.95, 1:3.71, 1:7.10, 1:7.49, 1:15.10, and 1:23.24 in 3D. The differences of percentage were 3.50%, 3.47%, 8.12%, 8.02%, 10.58%, and 11.06% in 2D, the minimum differentiation was 3.47%, and the maximum one was 11.06%. In 3D, the difference of percentage was 3.66%, 4.80%, 8.38%, 23.92%, 23.86%, and 22.69%. Conclusion: The difference of accumulated concentrations is significantly increased following enhancement of radioactivity concentration. The change of radioactivity density in 2D image is affected by less than 3D. For those reasons, when patient is examined as follow up scan with changing the acquisition mode, scan should be conducted considering those things may affect to the quantitative analysis result and take into account these differences at reading.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.1
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• pp.3-8
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• 2009

Purpose: Onco flash shortens a scan time with half and there is a possibility of getting the data which corresponds in existing. The experiment which makes the image whose Onco Flash is excellent OSEM tried, as changes parameter of time, iteration. After reconstituting an image, produces FWHM and executes an evaluation. Materials and Methods: Siemens e.cam gamma camera, standard Jaszczak phantom and spatial resolution phantom was used. In order for the bubble not to enter, implants 2 mCi and volume 0.25 cc $^{99m}Tc$ respectively in line 3 to spatial resolution phantom. Put on that phantom on the table correctly, and acquires an image. 15 mCi putting in distilled water to mix $^{99m}Tc$ well in Jaszczak phantom and acquires image just like spatial resolution phantom. Reconstructs and converts the image to digital image as Sante program. Produce FWHM and evaluate by Amide. Results: The non-scattered image shows better FWHM value than scattered image. As time increases from 10 sec to 30 sec for 5sec interval, FWHM appeared to 30.1, 28.5, 24.5, 23.6, 23.4 mm. At the standard iteration value 4, OSEM FWHM shows 8.0 mm, and Onco Flash is 8.1 mm. As fade in iteration, FWHM value more and more decreased. Conclusion: When using Onco Flash, shortens a scan time, and enhances image quality. Also, user can adjust the parameters to improve resolution. Therefore, patient and user are satisfied with these merits.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.1
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• pp.112-115
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• 2009

Purpose: The test had been applied for outpatient by end of 2006, however, it has been included in the medical examination since January 2007, as demand and interests have been gradually increasing in the thyroid gland disease and cancer. thus, we would necessarily evaluate usefulness of the test by comparing the number of patients who are diagnosed as "benignancy" by the medical test with the number of outpatient who attend and are diagnosed as autoimmune thyroid disease among the benign patient, in samsung medical center for a certain period. Materials and Methods: Based on the result for Anti-TPO Antibody test by RIA for the 12,937 patients in samsung medical center from October 2007 to March 2008, for six months, benignancy rate classified by sex and age is measured statistically and number of the patients who are diagnosed as autoimmune thyroid disease are kept tracked on. Results: According to the analysis of the Anti-TPO antibody test 1,135 of 12,937, which is 8.77% are benign and 218 treated patient of them, which is 19.2%, were diagnosed as autoimmune thyroid disease. Conclusions: Based on the statistics, usefulness of the test seem to have co relationship with derivation of autoimmune thyroid disease. this is 19.2% of probability relatively high. this figure, however, does not have strong relationship with specialty of the disease. Thus screening test seems to have somewhat effectiveness, considering other experiments and their margin.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.2
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• pp.31-36
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• 2017

Purpose Recently, the performance of PET/CT scanner has been improved and various techniques have been developed to increase the image quality such as Sensitivity and Resolution. The purpose of this study is to evaluate the usefulness of Q.Clear (a fully convergent iterative reconstruction) technique of GE Discovery IQ equipment to enhance the image quality. Materials and Methods All scans were acquired by Discovery IQ (GE Healthcare, MI, USA). In NEMA IEC Body Phantom test, Background to Hot-sphere (10 mm, 13 mm, 17 mm, 22 mm) ratio was 1:4 and scan time was 3 minutes. The images were reconstructed by VPHDs (VUE Point High-Definition + SharpIR) and Q.Clear to evaluate each Contrast. We injected 18F-FDG 187 M㏃ to PET/SPECT Performance Phantom. And then it was scanned for 4 minutes to evaluate Resolution and Uniformity. T-test statistical analysis was performed on SUVmax of small lesions less than 2 cm in 100 clinical patients regardless of disease type. Results In the NEMA IEC Body Phantom, the Contrast was $63.6{\pm}5.7%$ (VPHDs) and $75{\pm}4.8%$ (Q.Clear). In the PET/SPECT Performance Phantom, the Resolution was 9.2 mm (VPHDs) and 7.3 mm (Q.Clear). Uniformity of Q.Clear was 10.8% better than VPHDs. T-test statistic of the clinical patients showed a significant difference of p value of 0.021. Conclusion Both the phantom test and the clinical results showed that the quality of the image was improved in Q.Clear was applied. The SUVmax was highly measured in Q.Clear and the lesions were clearly distinguished visually. Therefore Q.Clear can be useful in various aspects such as dose-reduction, patients evaluation and image analysis.