• The Korean Journal of Nuclear Medicine
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• v.39 no.6
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• pp.445-455
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• 2005

Purpose: We developed an animal SPECT system using clinical Philips ARGUS scintillation camera and pinhole collimator with specially manufactured small apertures. In this study, we evaluated the physical characteristics of this system and biological feasibility for animal experiments. Materials and Methods: Rotating station for small animals using a step motor and operating software were developed. Pinhole inserts with small apertures (diameter of 0.5, 1.0, and 2.0 mm) were manufactured and physical parameters including planar spatial resolution and sensitivity and reconstructed resolution were measured for some apertures. In order to measure the size of the usable field of view according to the distance from the focal point, manufactured multiple line sources separated with the same distance were scanned and numbers of lines within the field of view were counted. Using a Tc-99m line source with 0.5 mm diameter and 12 mm length placed in the exact center of field of view, planar spatial resolution according to the distance was measured. Calibration factor to obtain FWHM values in 'mm' unit was calculated from the planar image of two separated line sources. Te-99m point source with i mm diameter was used for the measurement of system sensitivity. In addition, SPECT data of micro phantom with cold and hot line inserts and rat brain after intravenous injection of [I-123]FP-CIT were acquired and reconstructed using filtered back protection reconstruction algorithm for pinhole collimator. Results: Size of usable field of view was proportional to the distance from the focal point and their relationship could be fitted into a linear equation (y=1.4x+0.5, x: distance). System sensitivity and planar spatial resolution at 3 cm measured using 1.0 mm aperture was 71 cps/MBq and 1.24 mm, respectively. In the SPECT image of rat brain with [I-123]FP-CIT acquired using 1.0 mm aperture, the distribution of dopamine transporter in the striatum was well identified in each hemisphere. Conclusion: We verified that this new animal SPECT system with the Phlilps ARGUS scanner and small apertures had sufficient performance for small animal imaging.

• The Korean Journal of Nuclear Medicine
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• v.39 no.6
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• pp.473-480
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• 2005

Purpose: Adenosine myocardial perfusion SPECT has proven to be useful in the detection of coronary artery disease, in the follow up the success of various therapeutic regimens and in assessing the prognosis of coronary artery disease. The purpose of this study is to define the reproducibility of myocardial perfusion SPECT using adenosine stress testing between two consecutive Tc-99m sestaMIBI (MIBI) SPECT studies in the same subjects. Methods: Thirty patients suspected of coronary artery disease in stable condition underwent sequential Tc-99m MIBI SPECT studies using intravenous adenosine. Gamma camera, acquisition and processing protocols used for the two tests were identical and no invasive procedures were performed between two tests. Mean interval between two tests were 4.1 days (range: 2-11 days). The left ventricular wall was divided into na segments and the degree of myocardial tracer uptake was graded with four-point scoring system by visual analysis. Images were interpretated by two independent nuclear medicine physicians and consensus was taken for final decision, if segmental score was not agreeable. Results: Hemodynamic responses to adenosine were not different between two consecutive studies. There were no serious side effects to stop infusion of adenosine and side effects profile was not different. When myocardial uptake was divided into normal and abnormal uptake, 481 of 540 segments were concordant (agreement rate 89%, Kappa index 0.74). With four-grade storing system, exact agreement was 81.3% (439 of 540 segments, tau b=0.73). One and two-grade differences were observed in 97 segments (18%) and 4 segments (0.7%) respectively, but three-grade difference was not observed in any segment. Extent and severity scores were not different between two studios. The extent and severity scores of the perfusion defect revealed excellent positive correlation between two test (r value for percentage extent and severity score is 0.982 and 0.965, p<0.001) Conclusion: Hemodynamic responses and side effects profile were not different between two consecutive adenosine stress tests in the same subjects. Adenosine Tc-99m sestaMIBI SPECT is highly reproducible, and could be used to assess temporal changes in myocardial perfusion in individual patients.

• Economic and Environmental Geology
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• v.40 no.4
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• pp.403-418
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• 2007

The objective of this research was to characterize the fate and transport of Cr(VI) contaminated groundwater in the Daejeon industrial area. Five subsidiary monitoring wells were newly installed and two existing wells were utilized for the investigation and the reduction process of Cr(VI) contaminated groundwater of the Daejeon(Mun-pyeong) national groundwater monitoring station. The Cr(VI) concentrations at the shallow aquifer well of the station were in the range of 3.2-4.5 mg/L indicating continuous contamination. However, Cr was not detected at the deep bedrock well and the other monitoring wells except MPH-1 and 3. The Cr(VI) concentrations of MPH-1 and MPH-3 were below the drinking water guideline value (0.05 mg/L). Therefore, the plume of the Cr(VI) contaminated groundwater was predicted to be confined within the narrow boundary around the station. The soluble/exchangeable Cr(VI) concentrations were below the detection limit in all core and slime samples taken from the five newly installed wells. Although the exact source of contamination was not directly detected in the study area, the spatial Cr(VI) distribution in groundwater and characteristics of the core samples indicated that the source and the dispersion range were confined within the 100 m area from the monitoring station. The contamination might be induced from the unlined landfill of industrial wastes which was observed during the installation of an subsidiary monitoring well. For the evaluation of the natural attenuation of Cr(VI), available reduction capacities of Cr(VI) with an initial concentration of 5 mg/L were measured in soil and aquifer materials. Dark-gray clay layer samples have high capacities of Cr(VI) reduction ranging from 58 to 64%, which is obviously related to organic carbon contents of the samples. The analysis of reduction capacities implied that the soil and aquifer materials controlled the dispersion of Cr(VI) contamination in this area. However, some possibilities of dispersion by the preferential flow cannot be excluded due to the limited numbers of monitoring wells. We suggest the removal of Cr(VI) contaminated groundwater by periodical pumping, and the continuous groundwater quality monitoring for evaluation of the Cr(VI) dispersion should be followed in the study area.

• Economic and Environmental Geology
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• v.53 no.5
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• pp.565-583
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• 2020

In recent years, various social issues related to the natural radioactive elements detected in household goods and building materials are addressed, and should be solved promptly. In Korea, for more than 20 years, the Ministry of Environment has investigated the natural radioactive materials such as heavy metals, uranium, and radon in soil or groundwater. The origins of natural radioactive materials in them may have a close correlation with the geological factors including classification of rocks, petrogenetic origins, and deformation characteristics, but the exact geological correlations are not clarified because of the absence of the government policy preserved in the basement rocks, soils as well as groundwater in fault-related reservoirs. This study aims to perform a research on the correlation between the petrogeneses of the Phanerozoic plutonic rocks and natural radioactive concentrations in rocks (radon, uranium, thorium, potassium etc.) in Korea. Among the Phanerozoic plutonic rocks, alkaline plutonic rocks (syenite, monzonite and monzodiorite and alkali granite) show high U and Th concentrations by high solubilities of U, Th, Zr, REE, and Nb until the most extreme stages of magmatic fractionation (viz. crystal fractionation) due to high magma temperature and high alkalinity tendency. The highly fractionated high-K calalkaline and peraluminous granitic rocks (leucogranite, two-mica granite and leucocratic pegmatite are also U and Th concentrations compared with other less or medium fractionated granitic rocks (diorite, granodiorite and granite). The alkaline plutonic rocks are associated with intracontinental rifting and extensional environment after crustal thickening by collisional and subductional processes. In contrast, the dominant calc-alkaline granitic rocks in Korea are related to the arc environment of the subduction zone. In summary, the trends of the U, Th and K concentration from the Phanerozoic plutonic rocks in Korea are closely linked to the petrogenesis of the rocks in tectonic environment. The preliminary data for gamma-spectrometric mesurments of natural radionuclide contents (²²⁶Ra, ²³²Th and ⁴⁰K) in the Phanerozoic plutonic rocks show high values in the alkaline and highly fractionated granitic rocks.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.279-284
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• 1999

Fly ash is the fine ash particles that are flying out of chimney of the thermoelectric power plant where coals are used as fuel. There are two kinds of fly ashes from anthracite and bituminous coal. By scanning electron microscope(SEM) morphological feature of fly ash was confirmed to the exact spherical particles with the diameter variation from the fine to the largest about $50{\mu}m$(mainly silty particle). Surface of anthracite ash particle was very smooth but that of bituminous was somewhat coarse. To find the utilization of fly ash for improving soil permeability, soils of 4 kinds of different texture, clay, clay loam, sandy clay loam and sand mere applied with 7 levels of fly ash: 0, 10, 20, 40, 60, 80, 100%(w/w) and their saturated hydraulic conductivity(Ks) were determined at each application by constant head method. In clay soil with low water permeability, Ks value was increased about 10 times from $10^{-8}$ to $10^{-7}m\;s^{-1}$ level with application of 10% fly ash and it was slightly increased with increasing fly ash application from 40 to 80%. In clay loam Ks value was about $10^{-7}m\;s^{-1}$ level and its value was not influenced by the fly ash application. In sandy clay loam with relatively high permeability, Ks value was decreased about 10 times from $10^{-5}$ to $10^{-6}m\;s^{-1}$ level with application of 10% fly ash and also decreased about 50 times from $10^{-5}$ to $5.0{\times}10^{-7}m\;s^{-1}$ with application of more than 20% fly ash. In sand with very high permeability, Ks value was decreased about 10 times from $10^{-4}$ to $10^{-5}m\;s^{-1}$ level with application of 10% fly ash and also decreased about 100 times from $10^{-4}$ to $10^{-6}m\;s^{-1}$ level with application of 20% fly ash and continuously decreased about 500 times from $10^{-4}$ to $5.0{\times}10^{-7}m\;s^{-1}$ level with application of more than 40% fly ash. In conclusion by fly ash application saturated hydraulic conductivity was increased in clay soil, on the contrary it was decreased in sandy soils. Fly ash may be used as a material for amelioration of soil permeability.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.93-99
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• 2010

Purpose: Currently, PET/CT scan has been known to provide useful information to both preoperative and postoperative examination of cancer patients. Contracted stomach by the long fasting could cause difficulties of interpretation because of its size on reconstructed image data. To solve this problem, after the whole body PET/CT scan, patients were administrated in drinking 300 mL of water to expand stomach and performed additional scan on stomach region. Not only PET/CT scan but also CT performs this water-administration, and patients were take oral solution to make stomach expand for stomach cancer. When this scan performed, patients lay supine position. In this study, we evaluated the capacity of stomach through PET/CT scan with drinking water performed in supine and prone position so that we can distinguish exact location of cancer around pylorus and inferior wall of stomach. Furthermore, image data from supine and prone positions were analyzed the difference of volume of stomach through the change of standardized uptake values. Materials and Methods: From July 2009 to January 2010 in severance hospital, 30 patients who were diagnosed as early gastric cancer or advanced gastric cancer were chosen. All patients had PET/CT scan before the operation and have had follow-up PET/CT. The patients fast for at least 8 hours, and had an injection intravenously with $^{18}F$-FDG, 7.4 MBq (0.2 mCi/kg) per kilogram. They were rested for 60 minutes. Before the examination, all patients were administrated to drink water for 300 mL Patients had PET/CT scan with supine position around the region of stomach, whole body, and around the region of stomach with prone position after drinking another 300 mL of water respectively. Results: As a results of comparison between stomach capacity of 30 patients in supine and prone position, the study draw results that average capacity of stomach body was 460.29 $mm^2$ in supine position, and 641.39 $mm^2$ in prone position for 30 patients. The change of capacity shows 41.3% expanded in prone position. And there was no noticeable difference at maximum standardized uptake values in supine position and prone position. Conclusion: As results, stomach would have more expanded capacity in prone position than supine position. For patients who have physical disabilities to move freely, additional scan in prone position will be obstacle to perform. However, if additional scan in supine position add with the scan in prone position, it will be easier to diagnose stomach cancer. Moreover, we believe that this study will help the research for inventing support tools for patients who have physical disabilities in prone position.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.100-103
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• 2010

Purpose: $^{18}F$-FDG wholebody PET is to evaluate the tumor using glucose metabolism. The blood glucose level is important factor that affects on a result of examination. High glucose levels may interfere with tumor targeting due to competitive inhibition of FDG uptake by D-glucose. The blood glucose level measurement test strips used in the blood glucose measurement are classified into the capillary blood measurement test strips and general purpose measurement test strips that can measure the venous blood and capillary blood altogether depends on cases. The purpose of the study was to compare the blood glucose measurements between simultaneously obtained capillary and venous blood samples using the capillary blood measurement test strips, general purpose measurement test strips. Materials and Methods: A total of 46 subjects (32 males, 14 females) with a mean age of $57.3{\pm}12.3$ years were enrolled. The blood glucose estimation was performed with a Optium Xceed Glucometer (Abbott). Simultaneous capillary and venous blood samples were obtained from each subject. The blood glucose levels were measured using the capillary blood measurement test strips and general purpose measurement test strips. The capillary and venous measurements were compared using a pared t-test. Results: The mean capillary and venous glucose values using the general purpose measurement test strips were $95.2{\pm}12.4$ mg/dL and $104.1{\pm}14.4$ mg/dL, giving a statistically significant difference (p<0.001) between the mean values for the capillary and venous glucose samples (9.0 mg/dL; 95% confidence interval (CI) -11.2 to -6.7). The mean capillary and venous glucose values using the capillary blood measurement test strips were $91.5{\pm}13.6$ mg/dL and $108.6{\pm}16.2$ mg/dL, giving a statistically significant difference (p<0.001) between the mean values for the capillary and venous glucose samples (16.6 mg/dL; 95% CI -20.2 to -13.0). Conclusion: When measuring the blood glucose level before $^{18}F$-FDG PET examination, since the incorrect blood glucose level can be measured, it should note to measure the blood glucose level of the venous blood by the capillary blood measurement test strips. Therefore the measurement variation can be reduced to fulfill the standardized measurement procedure with the suitable measurement test strips, the preparation of the PET examination will be able to be clearly confirmed. In addition, the standardized procedure of the following measurement on the area which is same at all times the blood area in the blood glucose measurement among a capillary or a vein will be needed.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.203-208
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• 1999

Purpose: The information on the change of the relative renal function after operation is essential to set the initial treatment plan in unilateral hydronephrosis. So we analyzed the preoperative and postoperative relative renal function, and observed the functional changes by operation and reliability of the various factors in those changes. Materials and Methods: A retrospective trial was done of 81 patients, 35 ureteropelvic junction(UPJ) obstruction and 46 vesicoureteral reflux(VUR), among 393 patients undergoing operations at our institution from March. 1992 to February. 1997. The patients who had infravesical abnormalities, abnormal contralateral kidney and insufficient research data were excluded. We determined the relative renal functions using DTPA and MAG3 scan in UPJ obstruction and DMSA scan in VUR. The mean observation period after operation was 2.01(0.25-4) years. Results: A. UPJ Obstruction 1. The relative renal function was improved significantly after operation(P=0.0007). 2. The kidneys which have preoperative functions between 20% and 40% improved significantly in relative renal function comparing to the kidneys of the other functions(P=0.0046). B. VUR 1. The renal functions didn't improve significantly after operation(P>0.05). 2. There was no significant factor affecting the prognosis in renal functions. Conclusions: 1. The kidneys with UPJ Obstruction show the difference in functional improvement after operation according to the degree of the preoperative renal function, but more investigations about the exact value are needed. 2. In VUR there was no difference between preoperative and postoperative functions, the theoretical basis on objectives of the operation could be the symptoms or factors except the operation.

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.48-56
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• 2000

Purpose: Alport SD., the most common herectitary rephriris, is a renal disease with rapid progression. Deafness, ocular abnormalities and a specific EM finding may be associated in addition to a family history. We have aralyged retrospectively. Methods: We observed 12 children with Alport syndrome who were diagnosed at Dept. of pediatrics in Kyunghee Univ., College of Medicine, from Apr. 1991 until Jun. 1999. We used four criteria for diagnosis: renal disease, family history, deafness or eye abnormalities, and a specific finding in electron microscopy Results: 2 of 12 patients had all features of the four diagnostic criteria. We could not trace an exact family history in 3 patients, and 6 patients did not exhibit deafness or eye abnormality. One could not have renal biopsy because offer chronic renal failure. Other three criteria were observed in her. The ratio of male to female observed was 1:2 respectively and the mean age of initial renal symptom was 5.6 years. 9 of 12 patients had a family history of renal disease. In the audiogram and ocular examination for 11 of 12 cases, sensorineural hearing loss was observed in 6 and ocular abnormality in 2 cases. In electron microscopic finding, irregular thickness of the capillary basement membranes with lamination of lamina densa and foot process obliteration was noted in 9 of 11 and thin basement membrane with splitting and foot process obliteration was noted in the other 2. The mean period of follow-up was 3 6/12 years. And one patient developed the chronic renal failure until now and had kidney transplantation. Conclusion: For the diagnosis of Alport syndrome, the following four diagnostic criteria are very important : renal disease, family history, deafness or eye abnormalities, and a specific finding on electron microscopy. We expect that more patients can be detected through the analysis of these characteristics.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.12 no.1
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• pp.39-45
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• 2009

Purpose: Preterm infants are very susceptible to malnutrition because of a lack of storage of nutrients, immature digestion and metabolism, and accompanying diseases associated with prematurity. The purpose of this study was to evaluate the effects of nutritional support by the pediatric nutritional support team (pNST) on the clinical course of preterm infants in the neonatal intensive care unit (NICU). Methods: Between July 2003 and July 2006, 48 preterm infants who were admitted to the NICU at Seoul National University Bundang Hospital were included. The subjects were divided into the following two subgroups according to the presence of NST activity; pre-NST group (n=23) and NST group (n=25). Hospital records were reviewed retrospectively. Results: Forty-eight preterm babies were included (M：F=27：21; gestational age, 25~33 weeks). A dietician, pharmacists, or the pNST participated in the prescription of total parenteral nutrition (TPN) more rapidly in the NST group (p=0.000). The fasting periods and TPN administration periods were significantly decreased in the NST group compared to the pre-NST group (p=0.017 & p=0.001, respectively). The doses of calories, protein, and lipids administered via TPN were significantly increased in the NST group compared to the pre-NST group (p=0.016, p=0.000, and p=0.000, respectively). The total period on antibiotic therapy was significantly decreased in the NST group compared to the pre-NST group (p=0.007). Conclusion: Because nutritional support by the pNST is of benefit to the clinical course of preterm infants in the NICU, the pNST should recommend to improve the nutritional status and clinical outcome of preterm infants.