• Korean Journal of Radiology
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• v.21 no.5
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• pp.588-597
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• 2020

Objective: To investigate the value of combined chemical exchange saturation transfer (CEST) and conventional magnetization transfer imaging (MT) in detecting metabolic and structural changes of renal fibrosis in rats with unilateral ureteral obstruction (UUO) at 3T MRI. Materials and Methods: Thirty-five Sprague-Dawley rats underwent UUO surgery (n = 25) or sham surgery (n = 10). The obstructed and contralateral kidneys were evaluated on days 1, 3, 5, and 7 after surgery. After CEST and MT examinations, ¹⁸F-labeled fluoro-2-deoxyglucose positron emission tomography was performed to quantify glucose metabolism. Fibrosis was measured by histology and western blots. Correlations were compared between asymmetrical magnetization transfer ratio at 1.2 ppm (MTR_asym(1.2ppm)) derived from CEST and maximum standard uptake value (SUV_max) and between magnetization transfer ratio (MTR) derived from MT and alpha-smooth muscle actin (α-SMA). Results: On days 3 and 7, MTR_asym(1.2ppm) and MTR of UUO renal cortex and medulla were significantly different from those of contralateral kidneys (p < 0.05). On day 7, MTR_asym(1.2ppm) and MTR of UUO renal cortex and medulla were significantly different from those of sham-operated kidneys (p < 0.05). The MTR_asym(1.2ppm) of UUO renal medulla was fairly negatively correlated with SUV_max (r = -0.350, p = 0.021), whereas MTR of UUO renal medulla was strongly negatively correlated with α-SMA (r = -0.744, p < 0.001). Conclusion: CEST and MT could provide metabolic and structural information for comprehensive assessment of renal fibrosis in UUO rats in 3T MRI and may aid in clinical monitoring of renal fibrosis in patients with chronic kidney disease.

• The Korean Journal of Nuclear Medicine
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• v.33 no.3
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• pp.327-336
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• 1999

Purpose: To assess the quantitative accuracy and the clinical utility of 3D volumetric PET imaging with FDG in brain studies, 24 patients with various neurological disorders were studied. Materials and Methods: Each patient was injected with 370 MBq of 2-[$^{18}F$]fluoro-2-deoxy-D-glucose. After a 30 min uptake period, the patients were imaged for 30 min in 2 dimensional acquisition (2D) and subsequently for 10 min in 3 dimensional acquisition imaging (3D) using a GE $Advance^{TM}$ PET system, The scatter corrected 3D (3D SC) and non scatter-corrected 3D images were compared with 2D images by applying ROIs on gray and white matter, lesion and contralateral normal areas. Measured and calculated attenuation correction methods for emission images were compared to get the maximum advantage of high sensitivity of 3D acquisition. Results: When normalized to the contrast of 2D images, the contrasts of gray to white matter were $0.75{\pm}0.13$ (3D) and $0.95{\pm}0.12$ (3D SC). The contrasts of normal area to lesion were $0.83{\pm}0.05$ (3D) and $0.96{\pm}0.05$ (3D SC). Three nuclear medicine physicians judged 3D SC images to be superior to the 2D with regards to resolution and noise. Regional counts of calculated attenuation correction was not significantly different to that of measured attenuation correction. Conclusion: 3D PET images with the scatter correction in FDG brain studies provide quantitatively and qualitatively similar images to 2D and can be utilized in a routine clinical setting to reduce scanning time and patient motion artifacts.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.244-250
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• 2012

The results of analyzing the difference between performances of individual dosimeters on this research subjecting the PLD and TLD, which are the official personal dosimeters, through dosimetry are as follows. After scanning the integral dose using an automatic scanner, the values of two devices that went through dose adjustment process had a statistical difference in TLD and PLD measurements under each filming conditions which were 70kVp, 200mA, 0.012sec and 42kVp, 100mA, and 0.012sec (p<0.001 and p<0.001 respectively). As for the difference of measurement value between DAP and the two particles under 70kVp, 200mA, 0.012sec filming condition, TLD had a value lower than DAP average value by $44.2mGy{\cdot}cm^2$ and PLD had a value of $246.8mGy{\cdot}cm^2$ which was lower than DAP average value by $15.5mGy{\cdot}cm^2$, while under 42kVp, 100mA, 0.012sec filming condition, TLD had a value lower than DAP average value by $17.9mGy{\cdot}cm^2$ and PLD had a value of $82.6mGy{\cdot}cm^2$ which was lower than DAP average value by 7.6$mGy{\cdot}cm^2$. Also, compared to PLD, each of 10 devices measured dose value in TLD had a larger deviation between the particles, and for a reproducibility test which repeatedly measured one particle, PLD had ${\pm}1%$ which was lower than TLD's ${\pm}2%$. As such, PLD had a superior performance result in dose measurement capacities aspect compared to TLD, and therefore we could verify that PLD is more appropriate and advantageous in managing radiation-related task performing worker's personal radiation exposure management in the diagnostic radiation field.

• The Korean Journal of Pharmacology
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• v.24 no.2
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• pp.233-240
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• 1988

A simple and selective isocratic HPLC method for the analysis of tissue polyamine contents is described and applied on the study of the changes of the hepatic polyamine contents after partial hepatectomy in male rats. The hepatic polyamines are extracted with 0.4 M perchloric acid containing 2 mM disodium EDTA, and then the extract is redissolved in 100 ul of 1 M sodium carbonate and incubated with 300 ul of FNBT-dimethylsulfoxide (1: 100) mixture. The N-2'-nitro-4'-trifluoromethylphenyl drivatives of polyamines are separated through a ERC-ODS column in an isocratic mode with an acetonitrile-water (80:20) mobile phase within 20 min. per a sample, while monitoring the effluent at 242 nm. This improved method which could detect subnanogram of each polyamines is highly specific and reproducible as evidenced by the application of it on the study of the changes of polyamine contents in the regenerating rat liver after partial hepatectomy.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.126-130
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• 2012

Purpose : Methode an effective block was investigated to deal with volatile radioactive gas, short lived radioactive waste generated as a result of the routinely produced radiopharmaceuticals FDG (2-deoxy-2-[$^{18}F$]fluoro-D-glucose) and compound with $^{11}C$. Materials and Methods : All components of the radiation stack monitoring and data management system for continuous radioactive gas detection in the air extract system purchase from fixed noble gas monitor of Berthold company. TEDLAR gas sampling bags purchase from the Dongbanghitech company. TEDLAR gas sampling bags (volume: 10 L) connected via paraflex or PTFE tubing and Teflon 3 way stopcock. When installing TEDLAR gas sampling bags in Hot cell on the inside and not radioactive gas concentrations were compared. According to whether the Hot cell inside a activated carbon filter installed, compare the difference in concentration of the radioactive gas $^{18}F$. Comparison of radiation emission concentration difference of module a FASTlab and TRACElab. Results : Activated carbon filter are installed in the Hot cell, a measure of the concentration of radioactive gas was 8 $Bq/m^3$. Without activated carbone filter in the hot cell was 300 $Bq/m^3$. Tedlar bag prior to installation of the radioactive gases a measure of the concentration was 3,500 $Bq/m^3$, $^{11}C$ synthesis of the measured concentration was 27,000 $Bq/m^3$. After installed a Tedlar bag and a measure concentration of the radioactive gases was 300 $Bq/m^3$ and $^{11}C$ synthesis was 1,000$Bq/m^3$. Conclusion : $^{11}C$ radioactive gas that was ejected out of the Hot cell, with the use of a Tedlar gas sampling bag stored inside. A compound of 11C is not absorbed onto activated carbon filter. But can block the release out by storing in a Tedlar gas sampling bag. We was able to reduce the radiation exposure of the worker by efficient radiation protection.

• The Korean Journal of Nuclear Medicine
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• v.36 no.3
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• pp.166-176
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• 2002

Purpose: The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of $^{99m}Tc-HMPAO$ (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. Materials and Methods: The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and $^{99m}Tc-HMPAO$ SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the legion of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map (SPM99). Results: The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was $32.50{\pm}5.67%$. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Conclusion: Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann.

• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.65-75
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• 1999

Purpose: The aim of this study is to demonstrate the feasibility of 2-[fluorine-18] fluoro-2-deoxy-D-glucose (F-18-FDG) whole body scan (FDG W/B Scan) using dual-head gamma camera equipped with ultra high energy collimator in patients with various cancers, and compare the results with those of coincidence imaging. Materials and Methods: Phantom studies of planar imaging with ultra high energy and coincidence tomography (FDG CoDe PET) were performed. Fourteen patients with known or suspected malignancy were examined. F-18-FDG whole body scan was performed using dual-head gamma camera with high energy (511 keV) collimators and regional FDG CoDe PET immediately followed it Radiological, clinical follow up and histologic results were correlated with F-18-FDG findings. Results: Planar phantom study showed 13.1 mm spatial resolution at 10 cm with a sensitivity of 2638 cpm/MBq/ml. In coincidence PET, spatial resolution was 7.49 mm and sensitivity was 5351 cpm/MBq/ml. Eight out of 14 patients showed hypermetabolic sites in primary or metastatic tumors in FDG CoDe PET. The lesions showing no hypermetabolic uptake of FDG in both methods were all less than 1 cm except one lesion of 2 cm sized metastatic lymph node. The metastatic lymph nodes of positive FDG uptake were more than 1.5 cm in size or conglomerated lesions of lymph nodes less than 1cm in size. FDG W/B scan showed similar results but had additional false positive and false negative cases. FDG W/B scan could not visualize liver metastasis in one case that showed multiple metastatic sites in FDG CoDe PET. Conclusion: FDG W/B scan with specially designed collimators depicted some cancers and their metastatic sites, although it had a limitation in image quality compared to that of FDG CoDe PET. This study suggests that F-18-FDG positron imaging using dual-head gamma camera is feasible in oncology and helpful if it should be more available by regional distribution of FDG.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.225-236
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• 1998

KSC-13906 [Erythro N-{(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl} -2-(2-fluoro-1-hydroxy-n-propyl) benzenesulfonamide, US Patent 5,461,025] was investigated how can control phytotoxicity fluctuation and what a good method apply to new rice herbicide. The growth inhibition was observed when the rice plants was transplanted at a shallow depth(0 - 1cm) and leaching was low(0 - 1cm/ day) from the paddy soil. KSC-13906 appeared to move readily down into the paddy soil with water by 3cm depth in the soil column(${\phi}$ 10cm) filled with loamy sand soil under 3cm/day of leaching condition. Artificial control releasing pattern, designed as treated with KSC-13906 of 9 or 18g ai/ha either at a once or daily treated dividing volume of 1/20, 1/25 and 1/30 of the total volume, increased the safety of KSC-13906 to direct seeded and transplanted rice. The safety of KSC-13906 was also enhanced when KSC-13906 was mixed with dymron. For example, the mixture of KSC-13906 and dymron effectively reduced injury of direct seeded rice plants at 18 and 500g ai/ha, respectively, treated 7 days after transplanting. However, combination of KSC-13906 and several herbicides didn't show any synergistic effetct on herbicidal activity and safening effect on rice. However, the combination of KSC-13906+dymron (9~12+250~500g ai/ha) or KSC-13906+mefenacet+dymron(9+250+250g ai/ha) controlled almost all weeds in paddy field without causing any injury to rice and thus the combination would successfully be used as an oneshot herbicide in rice culture.

• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.484-492
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• 1996

To detect ischemic tissue in experimental model of cerebral ischemia made by middle cerebral artery(MCA)-occlusion, we acquired triple image of $^{99m}Tc$-glucarate, [$^{18}F$]fluoro-deoxyglucose (FDG), and 2,3,5- triphenyltetrazolium (TTC) staining. We made cerebral infarction either with reperfusion (after occlusion of 2 hours) or without reperfusion in 10 Sprague-Dawley rats by inserting thread to MCA through internal carotid artery. After 22 hours, we injected 740 MBq of $^{99m}Tc$-glucarate and 55.5 MBq of [$^{18}F$]FDG through tail vein. Each 1 mm slice of rat brains was frozen and exposed to imaging plate for 20 minutes in freezer to get an [$^{18}F$]FDG image. After 20 hours enough to fade radioactivity of [$^{18}F$]FDG, the slices were again imaged by BAS1500 for $^{99m}Tc$-glucarate uptake. Finally, these brain tissues were stained with TTC. Semi-quantitative visual analysis was done by grading 0 to 3 points according to the degree of uptakes($^{99m}Tc$-glucarate) and decreased uptakes([$^{18}F$]FDG and TTC). Ten rats survived with neurologic symptoms. TTC staining confirmed the development of infarction. The size of the infarction was relatively larger in the group without reperfusion. [$^{18}F$]FDG images were similar to TTC-stained images. However, we found regions with intermediate uptake which were not stained with TTC. We found regions with intermediate [$^{18}F$]FDG uptake where TTC staining was normal. $^{99m}Tc$-glucarate uptake was round only in TTC non-stained region. In the TTC stained regions, there were no uptake of $^{99m}Tc$-glucarate. We could not find clear relation between $^{99m}Tc$-glucarate uptake with [$^{18}F$]FDG uptake. This was partly because percent uptake of $^{99m}Tc$-glucarate was so small (less than 1 percent of injected dose) and because there were quite heterogeneity of patterns of [$^{18}F$]FDG uptake and TTC. With these findings, we could conclude that $^{99m}Tc$-glucarate were taken up only in part of ischemic tissues which were proven to be nonviable. The establishment of MCA-occluded rat model with or without reperfusion and triple imaging for $^{99m}Tc,\;^{18}F$ and TTC helped the characterization of $^{99m}Tc$-glucarate uptakes. Further work is needed to clarify the meaning or diversities or [$^{18}F$]FDG and TTC and their relation with $^{99m}Tc$-glucarate.

• Radiation Oncology Journal
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• v.22 no.2
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• pp.98-105
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• 2004

Purpose : To evaluate whether positron omission tomography (PET) with 2-[F-18]fluoro-2-deoxy-D-giucose(FDG) can be used to predict of early response to definitive aim radlotherapy (RT) in squamous cell carcinoma of the head and neck using response rate and locoreglonal control as study endpoints. Materials and Methods : Twenty-two patients with head and neck cancer underwent a FDG-PET study before RT, after a flrst dose of 45 Gy, and after a second dose on more 4han 70 Gy. Standard uptake value (SUV) was calculated for primary tumor (n=22) and neck lymph node (n:10). Attenuation corrected PET scans acquired 60 min after tracer injection were used for evaluation of FDG uptake In tumors. A quantitative FDG uptake index was expressed as Suvlean (corrected for iean body mass). The follow-up time was at least 5 months (range S-1 S months). Results : A total of 22 primary tumors and 10 metastatic lymph nodes were analyzed In FDG-PET. In the first PET study the mean SUVlean the primary tumors and nodes were 5.4 (SD, 2.5) and 4.6 (SD, 2.3), respectively. In the second PET, study peformed after 46 Gy RT the mean SUV in primary tumor and node decreased to 2.9 (SD, 1.9, p<0.001) and 1.7 (SD, 1.3) respectively. in the third PET study peformed at the full dose (more than 70 Gy), RT the mean SUV In the primary tumors and nodes decreased to 2.3 (SD, 1.5, p<0.001) and 1.5 (SD, 1 .1) respectively. Conclusions: FDG uptake In tumors showed a significant decrease after the 45 Gy and more than 70 Gy of RT for squamous cell carcinoma of the head and neck. Reduction of metabolic activity after 46 Gy of radiotherapy Is closely correlated with radiation response.