• The Korean Journal of Nuclear Medicine
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• v.32 no.3
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• pp.238-249
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• 1998

Purpose: To localize and compare the neural basis of verbal and visual human working memory, we performed functional activation study using $H_2^{15}O$ PET. Materials and Methods: Repeated $H_2^{15}O$ PET scans with one control and three different activation tasks were performed on six right-handed normal volunteers. Each activation task was composed of 13 match-ing trials. On each trial, four targets, a fixation dot and a probe were presented sequentially and subject's task was to press a response button to indicate whether or not the probe was one of the previous targets. Short meaningful Korean words, simple drawings and monochromic pictures of human faces were used as matching objects for verbal or visual memory. All the images were spatially normalized and the differences between control and activation states were statistically analyzed using SPM96. Results: Statistical analysis of verbal memory activation with short words showed activation in the left Broca's area, promoter cortex, cerebellum and right cingulate gyrus. In verbal memory with simple drawings, activation was shown in the larger regions including where activated with short words and left superior temporal cortex, basal ganglia, thalamus, prefrontal cortex, anterior portion of right superior temporal gyrus and right infero-lateral frontal cortex. On the other hand, the visual memory task activated predominantly right-sided structures, especially inferior frontal cortex, supplementary motor cortex and superior parietal cortex. Conclusion: The results are consistent with the hypothesis of the laterality and dissociation of the verbal and visual working memory from the invasive electrophysiological studies and emphasize the pivotal role of frontal cortex and cingulate gyrus in working memory system.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.1
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• pp.86-92
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• 2009

Purpose: The PET/CT has a clear distinction on the lesion of the functional image by adding anatomical information. It also could reduce the examination time using CT data as the attenuation-correction. When the stomach was contracted from a fast, it could bring a misinterpretation of the cancer of the lesion with a presence of physiological $^{18}F$-FDG uptake in stomach and it occasionally would bring an additional scan to confirm. To complement this shortcoming, the method that the patients had water before the examination to extend the stomach had been attempted. However, a short excretion time of the stomach did not give sufficiently extended image of the stomach. Then the patients had additional water and had the examination again. Therefore, the noticed fact is that the stomach excretion time depends on calories, protein content, and the level of carbohydrate. In this study, we use an orange juice to evaluate the extension of the stomach and usefulness of it. Materials and Methods: PET/CT scan were obtained on total 150 of patient from February 2008 to October2008, There were 3 groups in this study and each group had 50 patients. First group drank nothing, Second group drank water and third group drank orange juice. The patients (man 25, female 25) not drinking are the age of 30~71 years old (average: 54), the patients (man: 25, female: 25) drinking water (400 cc) are the age of 28~71 years old (average: 54) and the patients (man: 25, female: 25) drinking orange juice (400 cc) are the age of 32~74 years old (average: 56). The patients were fasted in 6-8 hours before the test, the patients were not diabetic. $^{18}F$-FDG 370~555 MBq were injected intravenously. The patients were in stable position for 1 hour, than the image was obtained. The patients drank water and other patients drank orange juice before Whole body scan. The image scan started from mid-femur to skull base. The emission scan acquired for three minutes per bed and the images were reconstructed. Stomach extension analysis is measured from vertical and horizontal length. Results: Stomach Extension was described as the vertical length of the Non Drink Group was $1.20{\pm}0.50\;cm$, horizontal length was $1.4{\pm}0.53\;cm$, the vertical length of the Water Drink Group was $1.67{\pm}0.63\;cm$, horizontal length was $1.65{\pm}0.77\;cm$, the vertical length of Orange juice Drink Group was $3.48{\pm}0.77\;cm$, horizontal length was $3.66{\pm}0.77\;cm$ in coronal image. Stomach Extension was described the vertical length of the Non Drink Group was $2.03{\pm}0.62\;cm$, horizontal length was $1.69{\pm}0.68\;cm$, the vertical length of Water Drink Group was $5.34{\pm}1.62\;cm$, horizontal length was $2.45{\pm}0.72\;cm$, the vertical length of Orange juice Drink Group was $7.74{\pm}1.62\;cm$, horizontal length was $3.57{\pm}0.77\;cm$ in transverse image. The Stomach Extension has specific differences (p<0.001). The SUVs shows the Non Drink Group were measured as Liver $2.52{\pm}0.42$, Lung $0.51{\pm}0.14$, the Water Drink Group were measured as Liver $2.47{\pm}0.38$, Lung $0.50{\pm}0.14$, Orange juice Drink Group were measured as Liver $2.47{\pm}0.38$, Lung $0.50{\pm}0.14$. The SUVs did not have specific differences (p>0.759). Conclusions: There was not a large difference of SUV in three groups. When the patients drank Orange juice and water, the range extension of stomach was higher than without drinking nothing and it was possible to acquire fully extended images. Therefore, it will be possible that unnecessary additional stomach scans will be reduced by drinking orange juice before the examination so that the patients' claim from uncomfortable and long period of fast will be minimized.

• The Korean Journal of Nuclear Medicine
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• v.33 no.2
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• pp.120-130
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• 1999

Purpose: This study was performed to evaluate the diagnostic usefulness of double-phase Tc-99m MIBI parathyroid scintigraphy with single photon emission computed tomography (SPECT) in patients with hyper-parathyroidism. We also evaluated the relationship between Tc-99m MIBI uptake and oxyphil cell contents in parathyroid glands. Materials and Methods: The subjects were 28 parathyroid glands of 10 patients who underwent Tc-99m MIBI parathyroid scintigraphy and parathyroidectomy for clinically suspected hyper-parathyroidism. Early and delayed pinhole images were obtained at 15 minutes and 2 hours after injection of Tc-99m MIBI, and SPECT images were followed. The weight and oxyphil cell contents of parathyroid tissue were obtained from pathologic specimen, and the scintigraphic findings were compared with histopathology. Results: In surgical histopathology, 6 parathyroid adenomas and 9 parathyroid hyperplasias were confirmed. The sensitivity, specificity, and positive predictive value of early and delayed images were 46.7% (7/15), 76.9% (10/13), 70% (7/10) and 66.7% (10/15), 92.3% (12/13), 90.9% (10/11), respectively. SPECT image detected an additional small hyperplasia.. The sensitivity, specificity, and positive predictive value of combined interpretation of early and delayed images with SPECT were 73.3% (11/15), 100% (13/13), 100% (11/11). The sensitivity was 100% (6/6) for adenoma, whereas that was 55.5% (5/9) for hyperplasia. Both adenomas and hyperplasias showed significantly increased oxyphil cell contents compared with normal parathyroid glands (p<0.0001), but the oxyphil cell content and weight were not significantly different between adenomas and hyperplasias. Conclusion: Double-phase Tc-99m MIBI parathyroid scintigraphy with SPECT is useful for lesion localization in patients with hyperparathyroidism. Although both adenoma and hyperplasia have increased oxyphil cell content, the sensitivity is high in adenoma, but low in hyperplasia.

• Journal of Acupuncture Research
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• v.19 no.1
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• pp.127-134
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• 2002

Background and Purpose : Now, a lot of people are suffering from arthritis of knee joint. Western and oriental medicine, all of them are trying various methods to cure this disease, but generally the grade or level of repairing has been decided by the subjective estimation of the patients and doctors. So, we suggest the new standard for estimating the level of repair in this disease using nuclear medicine. Objective : To evalute the difference of the blood pool and delayed images in the correlation with clinical symptoms in patients with arthritis of knee joint by using acupuncture. Methods : Eight patients with arthritis of knee joint included in this study. Using Thermograph (D.I.T.I) and Radionuclide, we obtained the results. In Bone scan Tc-99m MDP, and MIBI scan was obtained at 1 minute and 3 hour after injection of 1,110 MBq Tc-99m MDP and MIBI. The analysis was carried out hurted area of joint. The Joint-to-background(J/B) ratios were obtained exclusively in the joints regions. Clinical symptoms were evaluated as pain and swelling graded from 0(no) to 5(severe) in the same joints, respectively. Results : J/B ratios on the delayed scans were higher than those on blood pool images. There was significant correlation between clinical symptoms and J/B on blood pool image in the joints =0.03). Conclusion : The results demonstrate that blood pool images of Tc-99m MDP scintigraphy correlates with clinical symptoms more than delayed images in patients with arthritis Joint.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.48-52
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• 2013

Purpose: The Molybdenum which is the raw material of $^{99}Mo-^{99m}Tc$ generator is produced from the nuclear reactor. However, output has dwindled as the two nuclear reactors supplying the bulk of radioactive material-one in Chalk River, Ontario and the other in Petten, the Netherlands-have been closed for repairs or maintenance. This resulted in the enhancement of its price. So $^{99}Mo-^{99m}Tc$ generator using$(n,{\gamma})^{99}Mo$ is developed by Korea Atomic Energy Research Institute (KAERI). Medicinal availability of this generator is evaluated in this study. Materials and Methods: The radioactivity of $^{99m}Tc$ eluted in generator 1, 2 and 3 unit developed by KAERI was measured. The quality control test of generator such as appearance test, pH test, LAL test, sterility test, chemical impurity (Al) test and radiochemical purity test were performed. Planar and SPECT/CT image sof SD rat (6 weeks, Female) at 2 hr after injection of $^{99m}Tc-HDP$ (hydroxymethylenediphosphonate) (TechneScan HDP, Malinckrodt Medical, Dutch) and $^{99m}Tc-DPD$ (diphosphono-1, 2-propanedicarboxylicacid) (TECEOS, CIS bio international, France) which were labeled with $^{99m}Tc$ eluted in KAERI and commercial generator (40.5 GBq, Malinckrodt Medical, Dutch) using SPECT/CT camera (Symbia, Siemense, Germany) were obtained respectively. Results: The mean radioactivity of $^{99m}Tc$ elution generator 1unit was 4.18 GBq (113 mCi), generator 2 unit was 4.73 GBq (128 mCi) and generator 3 unit was 3.33 GBq (90 mCi). All quality control tests were within normal limit except pyrogentest. Pyrogen test was positive. Planar and SPECT/CT images of rat injected $^{99m}Tc-HDP$ which was labeled with $^{99m}Tc$ eluted in commercial generator show increased uptake in bone, stomach and bowl. Planar images show increased uptake in liver and bone in case of $^{99m}Tc-DPD$. However, images of rat injected $^{99m}Tc-HDP$ and $^{99m}Tc-DPD$ which were labelled $^{99m}Tc$ eluted in KAERI generator show increased uptake in bone, liver and spleen. Conclusion: If shortcoming is removed such as pyrogen and liver appearance, domestic role as an alternative generator is thought to be able to fill and to secure the national medical service by supplying $^{99m}Tc$ when the supply of $^{99m}Tc$ be comes short.

• The Korean Journal of Nuclear Medicine
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• v.32 no.3
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• pp.290-297
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• 1998

Purpose : The aim of this study was to evaluate the feasibility of 3-[$^{131}I$]iodo-O-methyl-L-${\alpha}$-methyltyrosine ([$^{131}I$]OMIMT) as an agent for tumor image. Materials and Methods : After synthesis of 4-O-methyl-L-${\alpha}$-methyltyrosine (OMAMT), OMAMT was labeled with [$^{131}I$] using Iodogen method. In vitro cellular uptake study was performed using 9 L gliosarcoma cells at various time points upto 4 hr. The biodistribution (five rats implanted with the 9 L gliosar-coma cells per group) was evaluated at 30 min, 2 hr, 24 hr after iv injection of 3.7 MBq [$^{131}I$]OMIMT or L-3-[$^{131}I$]iodo-${\alpha}$-methyltyrosine [$^{131}I$]IMT). Gamma camera images were obtained at 30 min, 2 hr and 24 hr. Results: [$^{131}I$]OMIMT uptake was 3.3 times and 2.5 times higher than [$^{131}I$]IMT uptake at 30 min and 60 min, respectively and same after 2 hr in in vitro study using 9L gliosarcoma cells. Maximum accumulation in tumor occurred at 30 min for both [$^{131}I$]OMIMT and [$^{131}I$]IMT in tumor bearing rats. The tumor uptake of [$^{131}I$]OMIMT was significantly higher than that of [$^{131}I$]IMT at early time point studied ($3.74{\pm}0.48$ vs $0.38{\pm}0.17%$ ID/g at 30 min and $2.40{\pm}0.17$ vs $0.24{\pm}0.03%$ ID/g at 2 hr, respectively, p<0.01). However, the tumor uptake of both radiolabels were not significantly different at 24 hr ($0.04{\pm}0.01$ vs $0.05{\pm}0.01%$ ID/g). Tumor was visualized as early as at 30 min in gamma camera images. Conclusion: These data suggested that [$^{131}I$]OMIMT might be a useful tumor imaging agent and has more advantage for the tumor imaging compared to [$^{131}I$]IMT

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.2
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• pp.55-62
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• 2015

Purpose Various methods for reducing radiation exposure have been continuously being developed. The aim of this study is to evaluate effectiveness of dose reduction, image quality and PET SUV changes by applying combination of automatic exposure dose(AEC), automated dose-optimized selection of X-ray tube voltage(CAREkV) and sinogram affirmed iterative reconstruction(SAFIRE) which can be controled by user. Materials and Methods Torso, AAPM CT performance and IEC body phantom images were acquired using biograph mCT64, (Siemens, Germany) PET/CT scanner. Standard CT condition was 120 kV, 40 mAs. Radiation exposure and noise were evaluated by applying AEC, CAREkV(120 kV, 40 mAs) and SAFIRE(120 kV, 25 mAs) with torso phantom compare to standard CT condition. And torso, AAPM and IEC phantom images were acquired with combination of 3 methods in condition of 120 kV, 25 mAs to evaluate radiation exposure, noise, spatial resolution and SUV changes. Results When applying AEC, CTDIvol and DLP were decreased by 50.52% and 50.62% compare to images which is not applying AEC. mAs was increased by 61.5% to compensate image quality according to decreasing 20 kV when applying CAREkV. However, CTDIvol and DLP were decreased by 6.2% and 5.5%. When reference mAs was the lower and strength was the higher, reduction of radiation exposure rate was the bigger. Mean SD and DLP were decreased by 2.2% and 38% when applying SAFIRE even though mAs was decreased by 37.5%(from 40 mAs to 25 mAs). Combination of 3 methods test, SD decreased by 5.17% and there was no significant differences in spatial resolution. And mean SD and DLP were decreased by 6.7% and 36.9% compare to 120 kV, 40 mAs with AEC. For SUV test, there was no statistical differences(P>0.05). Conclusion Combination of 3 methods shows dose reduction effect without degrading image quality and SUV changes. To reduce radiation exposure in PET/CT study, continuous effort is needed by optimizing various dose reduction methods.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.2
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• pp.80-85
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• 2017

Purpose The D530c have cadmium zinc telluride(CZT) detectors that are arranged focus on the heart. This structural characteristic allows for quicker imaging without rotation, but this is sensitive to patient movement and can affect the test results. The aim of this study is to optimize the image quality by reducing patient movement during the examination. Materials and Methods We analyzed the patients' movements, and performed various activities such as provided patient education about correct breathing techniques and avoiding patient movements, and created breathing correction tools to minimize patient movement during exam. The 70 patients who underwent myocardial perfusion SPECT with D530c in November 2016 were categorized as the group before the corrective steps. Another 70 patients who underwent the procedure with D530c from February 14, 2017 to February 21, 2017 were categorized as the improvement group. Images acquired during stress and at rest were compared and analyzed by measuring the durations of heart movements over certain distances (4 mm, 8 mm, 12 mm, or more) noted on the x-, y-, and zaxes. Results After the activities, the durations of heart movements decreased in the images acquired both under stress and at rest. In particular, there were no large motions greater than 12 mm recorded in the stress images after the improvement. There was a significant difference (p<0.005) in the 4-mm and 8-mm fluctuations on the X-axis and the 8-mm fluctuations on the Z axis in the stress images, but there was no significant difference (p>0.005) in the other stress and rest intervals. Conclusion The decrease in the time of motion occurrence due to the 4 mm fluctuation distance that can occur through breathing can be understood as a result of the breathing being corrected through training and motion prevention tools. It is expected that the image quality will be improved by reducing the occurrence time according to the variation distance of 8 mm or 12 mm, which is expected as the actual movement of the patient other than the breathing.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.8-16
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• 2008

Purpose: To assess the effect of extracranial-intracranial (EC-IC) bypass surgery on hemodynamic improvement, we evaluated serial regional cerebral hemodynamic change of the middle cerebral artery (MCA) in symptomatic patients with atherosclerotic occlusion of the internal carotid artery (ICA) or MCA using $^{99m}Tc$-ECD acetazolamide stress brain perfusion SPECT (Acetazolamide SPECT). Materials and Methods: The patients who had suffered a recent stroke with atherosclerotic ICA or MCA occlusion underwent EC-IC bypass surgery and Acetazolamide SPECT at 1 week before and three to six months after surgery. For image analysis, attenuation corrected images were spatially normalized to SPECT templates with SPM2. Anatomical automated labeling was applied to calculate mean counts of each Volume-Of-Interest (VOI). Seven VOIs of bilateral frontal, parietal, temporal regions of the MCA territory and the ipsilateral cerebellum were defined. Using mean counts of 7 VOIs, cerebral perfusion index and perfusion reserve index were calculated. Results: Seventeen patients (M:F =12:5, mean age $53{\pm}2yr$) were finally included in the analysis. The cerebral blood flow of the parietal region increased at 1 week (p = 0.003) and decreased to the preoperative level at 3-6 months (p = 0.003). The cerebrovascular reserve of the frontal and parietal regions increased significantly at 1 week after surgery (p<0.01) and improved further at 3-6 months. Conclusion: Cerebrovascular reserve of the MCA territory was significantly improved at early postoperative period after EC-IC bypass and kept improved state during long-term follow-up, although cerebral blood flow did not significantly improved. Therefore, cerebrovascular reserve may be a good indicator of postoperative hemodynamic improvement resulted from bypass effect.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.91-95
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• 2012

Purpose: In this study, we evaluated the ejection fraction (EF) according to the difference of patient position in Gated Blood Pool (GBP) scan. Material and Methods: The analysis was performed to 80 patients ($51.2{\pm}17.4$ years old) who examined GBP scan in Department of nuclear medicine, National Cancer Center from March 2011 to August 2011. We divided the patients into two groups; one group received conventional position (raise left arm up supine) and supine position (group 1) and the other group received conventional position and left arm back down supine position (group 2). To observe the change EF according to patient position difference, the image was reconstructed and analyzed by Xeleris (GE, USA). We measured body mass index (BMI) of patients. Result: In group 1, EF error less than 3% occurred at a rate of 72.5% (29 of the 40 patients). In group 2, EF error less than 3% occurred at a rate of 79% (32 of the 40 patients). The patient's BMI did not affect ejection fraction. Conclusion: The EF error of left arm back down supine position closer to conventional position than in supine position shows the results.