• The Korean Journal of Nuclear Medicine
• /
• v.33 no.1
• /
• pp.100-109
• /
• 1999

Purpose: Preamplifier and amplifier are very important parts for developing a portable counting or imaging gamma probe. They can be used for analyzing pulses containing energy and position information for the emitted radiations. The commercial Nuclear Instrument Modules (NIMs) can be used for processing these pulses. However, it may be improper to use NIMs in developing a portable gamma probe, because of its size and high price. The purpose of this study was to develop both preamplifier and amplifier and measure their performance characteristics. Materials and Methods: The preamplifier and amplifier were designed as a charge sensitive device and a capacitor resistor-resistor capacitor (CR-RC) electronic circuit, respectively, and they were mounted on a print circuit board (PCB). We acquired and analyzed energy spectra for Tc-99m and Cs-137 using both PCB and NIMs. Multichannel analyzer (Accuspec/A, Canberra Industries Inc., Meriden Connecticut, U.S.A) and scintillation detectors (EP-047(Bicron Saint-Gobain/Norton Industrial EP-047 (Ceramics Co., Ohio, U.S.A) with $2"{\times}2"$ NaI(T1) crystal and R1535 (Hamamatsu Photonics K.K., Electron Tube Center, Shizuoka-ken, Japan) with $1"{\times}1"$ NaI(T1) crystal were used for acquiring the energy spectra. Results: Using PCB, energy resolutions of EP-047 detectors for Tc-99m and Cs-137 were 12.92% and 5.01%, respectively, whereas R1535 showed 13.75% and 5.19% of energy resolution. Using the NIM devices, energy resolutions of EP-047 detector for Tc-99m and Cs-137 were measured as 14.6% and 7.58%, respectively. However, reliable energy spectrum of R1535 detector could not be acquired, since its photomultiplier tube (PMT) requires a specific type of preamplifier. Conclusion: We developed a special preamplifier and amplifier suitable for a small sized gamma probe that showed good energy resolutions independent of PMT types. The results indicate that the PCB can be used in developing both counting and imaging gamma probe.

• Nuclear Medicine and Molecular Imaging
• /
• v.43 no.6
• /
• pp.543-556
• /
• 2009

Purpose: We studied the patterns of FDG uptake of primary papillary thyroid microcarcinoma (PTMCa) lesions and benign thyroid nodules in dual time point $^{18}F$-FDG PET/CT imaging. Materials and Methods: Consecutive 134 patients (154 lesions) with PTMCa and 49 patients (61 nodules) with benign thyroid nodules equal to or less than 1.0 cm who underwent dual time point $^{18}F$-FDG PET/CT study before surgery were enrolled. We calculated the maximum standardized uptake value of PTMCa and benign nodules in both time points, and percent change of SUVmax (${\Delta}%SUVmax$) and lesion to background ratio of SUVmax (${\Delta}L:B$% ratio) between both time points. The mean time interval between scans was $23.4{\pm}4.4$ minutes (thyroid to thyroid interval: $10.7{\pm}4.4$ minutes). Results: The mean of SUVmax of PTMCa was increased from $4.9{\pm}4.3$ to $5.3{\pm}4.7$ (p<0.001) and ${\Delta}%SUVmax$ was $12.3{\pm}23.6%$. But, the mean of SUVmax of benign nodules was no definite change ($2.1{\pm}1.0$ to $2.1{\pm}1.3$, p=0.686) and ${\Delta}%SUVmax$ was $-0.3{\pm}20.5%$. Of the 154 PTMCa, 100 nodules (64.9%) showed an increase in SUVmax over time, while 19 (31.1%) of the 61 benign thyroid nodules showed an increase (p<0.001). The dual time point $^{18}F$-FDG PET/CT found more PTMCa in visual assessment (62.3% vs. 76.6%, p=0.006), even in smaller than 0.5 cm (38.6% vs. 60.0%, p=0.011). Conclusion: Dual time time $^{18}F$-FDG PET/CT imaging was more useful than single time point $^{18}F$-FDG PET/CT imaging for distinction between PTMCa and benign nodule, especially when nodule showed equivocal or negative findings in single time point $^{18}F$-FDG PET/CT imaging or was smaller than 0.5 cm.

• Nuclear Medicine and Molecular Imaging
• /
• v.42 no.5
• /
• pp.375-382
• /
• 2008

A low iodine diet (LID) is the recommended preparation for radioactive iodine treatment. However, the recommended duration and stringency of LID are different among each recommendation. More stringent LID is expected in Korea because Korea is a iodine-rich region. We investigated the decrement of urine iodine excretion by two-week stringent LID for remnant thyroid ablation with radioactive iodine in Korean patients with thyroid cancer, prospectively. Material and Method: From November 2006, patients who referred to our hospital for remnant ablation after total thyroidectomy were included in this study. To decrease total body iodine, our protocol included three strategies. First, we checked medication which could inhibit the radioactive iodine uptake. Second, the date of 1-131 treatment was scheduled at least 3 months later if contrast agent had been used. The last strategy was two-week stringent LID education by specialized nutritionist. Before and after two-week stringent LID, 24hr-urine iodine was analyzed respectively. 24hr-urine creatinine was also analyzed for determining more valid 24hr urine sampling subgroup. Results: Total 51 patients were finally enrolled. Average of 24hr-urine iodine excretion was significantly lowered ($787{\pm}2242\;{\rightarrow}\;85{\pm}85\;{\mu}g/d$, p=0.03) after LID and 74.4% of patients reached below the recommended urine iodine excretion level ($<100\;{\mu}g/d$). In subgroup (n=14), similar results was showed ($505{\pm}666\;{\rightarrow}\;99{\pm}116\;{\mu}g/d$, p=0.05) and 78.6% of patients met the criteria. Conclusion: Most patients could reach below the recommended urine iodine level after two-week stringent LID. Therefore, in our opinion, at least two-week stringent LID should be recommended in Korea.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.15 no.1
• /
• pp.65-69
• /
• 2011

Purpose: Normal pancreas has low uptake rate in $^{18}F$-FDG PET scan. However, it is possible to diagnose malignancy of pancreatic cancer which has high uptake rate. Many studies approve a high prevalence of diabetes in pancreatic cancer and if the blood glucose level (BGL) is over the normal range, FDG uptake will be decreased and there will be inconvenience for patients from the delay time to reduce the high BGL or could cause difficulty to arrange the schedule. Therefore, we studied the relation of BGL and image quality in pancreatic cancer on PET. Materials and Methods: A hundred patients had PET scan. The prevalence of pancreatic cancer and diabetes were evaluated using SPSS ver. 17. The fasting BGL of patients were examined and sorted as diabetes mellitus (DM) group and Non-DM group. For the evaluation, patients were divided into 3 groups (Non-DM, DM; BGL${\geq}7.0mmol/L$, and DM; BGL<7.0 mmol/L). The ROI was drown on Liver and Lung for the PET imaging analysis. Results: Fifty three male and forty seven female were in the patients. The average age was $60.1{\pm}13.5$. There were 36 patients (male: 22, female: 14, 36%) who had pancreatic cancer with DM. There were 15 patients who showed over 7.0 mmol/L in their fasting BGL and 85 patients who showed under 7.0 mmol/L in their fasting BGL. Among the Non-DM, DM; BGL${\geq}7.0mmol/L$, and DM; BGL<7.0 mmol/L, there was not a statistical significance (p>0.05). Conclusion: The prevalence of pancreatic cancer was comparatively high in this study. If the fasting BGL was slightly over the normal BGL, we believe it will not give a severe disturbance when the patients have PET scan. Furthermore, the examination schedule doesn't need to change and the inconvenience from the delay of patients preparation will be reduced.

• Korean Journal of Clinical Laboratory Science
• /
• v.49 no.4
• /
• pp.350-358
• /
• 2017

The hemolysis index (HI) is semi-quantitative marker for hemolysis. Because the characteristics of the HI vary from one commercial platform to another, no standardization or harmonization of the HI is currently available. Specimens (N=40) randomly selected from clinical patients were artificially hemolyzed in vitro. The serum of the specimens was then diluted with a 20 mg/dL difference between 0~300 mg/dL based on serum hemoglobin measured using the XE-2100 hematology automation equipment (Sysmex, Japan). Diluted serum was measured using the Hitachi-7600 biochemical automation equipment (Hitachi, Japan) to differentiate between HI and serum hemoglobin. The data showed linearity between HI and serum hemoglobin and that HI 1 contained approximately 20 mg/dL of serum hemoglobin. To determine the blood rejection threshold, the HI was divided into three groups: HI 0~1, HI 4~6, HI 9~15. After another batch of clinical specimens (N=40) was measured using a Hitachi-7600 (Hitachi, Japan), each specimen was moved forward and backward with the piston of the syringe to induce an artificial in vitro hemolysis, then measured again with a Hitachi-7600 (Hitachi, Japan). The percentage difference between the three groups was analyzed by ANOVA or the Kruskal-Wallis test. In the post-test, there were significant differences between the HI 0~1 and the HI 5~6: Glucose, creatinine, total protein, AST, direct bilirubin, uric acid, phosphorus, triglyceride, LDH, CPK, Magnesium, and potassium levels. Because many clinical tests differed significantly, the threshold for hemolysis could be appropriate for HI 5 (serum hemoglobin 100 mg/dL).

• Journal of Food Hygiene and Safety
• /
• v.25 no.3
• /
• pp.238-244
• /
• 2010

Currently, in vitro suspension tests using tubes are used as a authorized test method for sanitizers and disinfectants. However, the methods could not accurately assess the efficacy of sanitizers and disinfectant on the food-contacted surfaces in the field. This study evaluated the effectiveness of 5 kinds of representative sanitizers and disinfectants against E. coli and S. aureus to compare three quantitative surface testing methods that have been internationally standardized. As a result, the ASTM E2111-05 (ASTM(1)) test method obtained 5.18 $\pm$ 0.03 and 5.27 $\pm$ 0.04 log cfu/carrier reduction in dealing with E. coli and S. aureus, respectively, the ASTM E2197-02 (ASTM(2)) test method obtained 4.63 $\pm$ 0.04 and 3.97 $\pm$ 0.03 log cfu/carrier reduction and the CEN EN 13697 test method should 6.14 $\pm$ 0.05 and 5.31 $\pm$ 0.10 log cfu/carrier reduction in clean condition (CEN(1)) but 4.37 $\pm$ 0.02 and 4.06 $\pm$ 0.01 log cfu/carrier reduction in dirty condition (CEN(2)). Among them, CEN(1) showed the highest bactericidal effects, whereas ASTM(2) and CEN(2) revealed low performance (p < 0.05). In conclusion, the bactericidal effects of the ASTM(2) method and the CEN EN 13697 method adopting stainless steel were lower than the ASTM(1) method, which uses glass. The effectiveness assessment results among nationally accredited test methods were different each other. This implies that they could not fit for in the accurate evaluation of sanitization and disinfection on food-contact surfaces in practical food-processing fields. These results could be used as a basic data for establishment of an official surface test methods applicable in the field.

• Korean journal of food and cookery science
• /
• v.26 no.6
• /
• pp.745-752
• /
• 2010

The purpose of this study was to investigate the perceptions and preferences held by the general public concerning jeungpyun. Self-administered questionnaires were collected from 484 residents in Daegu and Gyeongbuk. The questionnaires contained questions on the recognition of jeungpyun, purchasing, frequency, purchasing factor, and preferences for and purchasing of jeungpyun containing different kinds of makgeoilli. According to the survey, females were higher than males (31.4%) by 69.7%, and that for ages 20~30' was the highest. Most of them were students (39.7%), and 81.7% of them had an income of under 4,000,000 won per month. The results of the eating frequency rate showed that over half of the people had jeungpyun once a month, and the recognition of jeungpyun for females (3.63) was higher than that for males (3.09). The respondents who joyed eating jeungpyun mentioned 'good taste and texture' as the top reason for eating jeungpyun, and 'different food and bad flavor' was mentioned as the reason for disliking it. As a result, popularization of jeungpyun was based on two factors: 1) fundamental factor and 2) external factor, and both significantly influence the preference for and purchasing of jeungpyun,-. Therefore, future studies should be conducted to improve preference for jeungpyun as a functional food. The results of preference and purchasing show that jeungpyun prepared with rice, rubus coreanum miquel, black bean, grape and green mume makgeoilli.

• Journal of the Korean Regional Science Association
• /
• v.34 no.2
• /
• pp.3-19
• /
• 2018

The objective of this study is to observe the efficiency of clinical performance on the supply and demand of medical resources in Korea. For the empirical analysis, we constructed the dataset on age standardized mortality rate, the number of physician, specialist, surgery, medical institution, ratio of general hospitals of 16 provinces in Korea from 2006 to 2013. The panel probability frontier model is employed as an analysis method and considered heteroscedasticity and autocorrelation of the error in panel data. In addition, the demographic and socioeconomic characteristics of the 16 provinces, unemployment rate, elderly population ratio, GRDP per capita, and ratio of hospitals in comparison to the general hospitals are used to find the effect on the technical efficiency of clinical performance on supply and demand of medical resources. The results are as follows. First, for the clinical performance, the supply side of human resources such as doctors and specialists and the demand side factors such as chronic illness clinic per unit population have a significant influence, respectively. Second, the technical efficiency of clinical performance on the supply and demand of medical resources of each input component was 59-70% in terms of clinical efficiency in each region. Third. estimates of technical efficiency of inputs that affect clinical performance showed a slight increase in all regions during the analysis period, but the increase trend decreased slightly. Fourth, the ratio of the elderly population and GRDP per capita have a positive influence on the technical efficiency of clinical performance on the supply and demand of medical resources. The difference of each efficiency by region is due to the regional differences of the input medical resources and the combination of them and the demographic and socioeconomic characteristics of the region. It is understood that the differences in technological efficiency due to the complexity of supply and demand of medical resources, demographic structure and economic difference affecting clinical performance by region are different.

• The Journal of the Petrological Society of Korea
• /
• v.12 no.1
• /
• pp.16-31
• /
• 2003

The granites in the southern Gimcheon area can be divided into two parts, marginal hornblende biotite granodiorite (Mgd) and central biotite granodiorite to granite (Cgd). Mgd and Cgd are gray in color and display gradational contact relations and are mainly composed of coarse-grained and medium-grained rocks, respectively. Mgd has more frequent and larger mafic enclaves than Cgd, and the two granites partly show parallel foliation at thire contact with gneisses. From representative samples of the granites, K-Ar biotite ages of 197∼207 Ma were obtained. Considering the blocking temperature of biotite, it is suggested that the emplacement age of the granitic magma was probably late Triassic. The anorthite contents of plagioclases in Mgd display less variation than those of Cgd, indicating that Mgd crystallized within a narrow range of temperatures. In the Al$\_$total/-Mg diagram, the biotites from the granites plot within the subalkaline field, and the smooth slope indicates differentiation from a single magma. All amphiboles from the granites belong to magnesio-hornblende. The linear trends of major oxides, AFM and Ba-Sr-Rb indicate that Mgd and Cgd were fractionally differentiated from a single granitic magma body crystallizing from the margin inwards. The relations of modal (Qz+Af) vs. Op, K$_2$O vs. Na$_2$O, Fe$_2$ $O_3$ vs. FeO, Fe$\^$+3/(Fe$\^$+3/+Fe$\^$+2/) and K/Rb vs. Rb/Sr show that they belong to I-type and magnetite-series granitic rocks developed by the progressive melting products of fixed sources. REE data, normalized to chondrite value, have trends of enriched LREE and depleted HREE together with weakly negative Eu anomalies.

• Radiation Oncology Journal
• /
• v.22 no.3
• /
• pp.184-191
• /
• 2004

Purpose: In order to improve the proper use of radiotherapy and breast-conserving treatment (BCT) in the management of breast cancer, current status of breast cancer treatment in Korea was surveyed nationwide and the use of BCT were evaluated. Materials and Methods: Patients characteristics and treatment pattern of 1048 breast cancer patients from 27 institutions diagnosed between January, 1998 and June, 1998 were analyzed. The incidence of receiving BCT was analyzed according to the stage, age, geography, type of hospital, and the availability of radiotherapy facility. Results: Radical mastectomy was peformed in 64.8$\%$ of total patients and 26$\%$ of patients received breast- conserving surgery (BCS). The proportions of patients receiving BCT were 47.5$\%$ in stage 0, 54.4$\%$ in stage I, and 20.3$\%$ in stage II, Some of the patients (6.6$\%$ of stage I, 10.1$\%$ of stage II and 66.7$\%$ of stage III) not received radiotherapy after BCS. Only 45$\%$ of stage III patients received post-operative radiotherapy after radical mastectomy. The proportion of patients receiving BCT was different according to the geography and availability of radiotherapy facilities. Conclusion: Radiotherapy was not fully used in the management of breast cancer, even in the patients received breast-conserving surgery. The proportion of the patients who received BCT was lower than the report of western countries. To improve the application of proper management of breast cancer, every efforts such as a training of physicians, public education, and improving accessibility of radiotherapy facilities should be done. The factors predicting receipt of BCT were accessibility of radiotherapy facility and geography. Also, periodic survey like current research is warranted.