• 대한핵의학회:학술대회논문집
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• 1998.11a
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• pp.45.2-45.2
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• 1998

• 대한핵의학회:학술대회논문집
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• 1998.11a
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• pp.47.1-47.1
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• 1998

• The Korean Journal of Nuclear Medicine
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• v.32 no.1
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• pp.50-60
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• 1998

I-123 labelled fatty acids are suitable for investigation of regional myocardial metabolism, so they are on the clinical trial. However, the precise properties of these materials are not characterized yet. We have synthesized phenylpentadecanoic acid and labeled this compound with I-123. The purpose of this study was to examine the stability, biodistribution, metabolism and SPECT imaging of [I-123]15-(p-iodophenyl)pentadecanoic acid(I-123-IPPA) that we made. The stability test of I-123-IPPA in serum of rat, mouse and human showed no free I-123 after 1 hour. In biodistribution study in mice for various time intervals after injection(5, 10, 15, 30, 60 minutes), uptake in myocardium was 14.5%ID/g(5 min), and 1.9%ID/heart(5 min), while uptake in muscles was 2.6%ID/g(5 min). Myocardium to blood ratio and myocardium to lung ratio increased for 5 min after injection and then decreased rapidly. Chromatographic data of rat blood and urine showed that little PPA was found in blood and urine at 15-20 min after injection. The myocardial I-123-IPPA SPECT images of a dog with myocardial infarction showed defects similar to those of Tc-99m-MIBI and F-18-FDG. These data suggest that I-123-IPPA is quite stable in vitro and shows favorable biodistribution in mice. SPECT imaging with I-123-IPPA demonstrated infarct zone as photon defect in dog model of myocardial infarction. I-123-IPPA may be used for the evaluation of fatty acid metabolism in clinical trials in Korea.

• 대한핵의학회:학술대회논문집
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• 2004.11a
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• pp.395.1-395.1
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• 2004

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2410-2412
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• 2011

Using a single step chemical synthesis, we synthesized the potential tumor imaging agent $^{99m}Tc$-diglucose-diethylenetriamine (DGTA) from diethylenetriamine and natural D-glucose. 10 min Incubation of 10 mg of precursor with 50 ${\mu}g$ of $SnCl_2{\cdot}2H_2O$ at room temperature yielded over 95% of $^{99m}Tc$ labeling. The stability for 6 hours in saline or human plasma was over 90%. In vitro tumor cell uptake assays using the SNU-C5 and 9 L cell lines showed that, in 0-400 mg/dL glucose medium, cell uptake of $^{99m}Tc$-DGTA was 1.5-8 times higher than that of [$^{18}F$]FDG. Moreover, [$^{18}F$]FDG uptake was dependent on glucose concentration in the medium, whereas cellular uptake of $^{99m}Tc$-DGTA was not dependent on glucose concentration, suggesting that the two compounds have different uptake mechanisms by tumor cells.

• 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.

• 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 Technology
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• v.16 no.2
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• pp.35-43
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• 2012

Purpose : PET/CT performed CT-based attenuation correction generates the beam hardening artifact by metallic implant. The attenuation correction causes over or underestimate of the area adjacent to metallic hip prosthetic material and change of $^{18}F$-FDG uptake. Also, the image quality and the diagnosability on genitourinary disease are reduced. Therefore, this study will evaluate the usefulness of MAR (Metal Artifact Reduction) algorithm method to improve the image quality on PET/CT. Materials and Methods : PET/CT was performed by fixing hip prosthesis in SPECT/PET phantom. In PET images with and Without MAR algorithm, the Bright streak, Dark streak, Metal region and Background area that appeared on CT were confirmed, and the change of each SUV (standardized uptake value) was analyzed. Also, in 15 patients who underwent total hip arthroplasty, each MAR algorithm and Without MAR algorithm and non attenuation correction was evaluated. Results : In PET image Without MAR algorithm, SUV of Bright streak region was $0.98{\pm}0.48$ g/ml; Dark streak region was $0.88{\pm}0.02$ g/ml; Metal region was $0.24{\pm}0.16$ g/ml, Background area was $0.91{\pm}0.18$ g/ml. In SUV of PET image with MAR algorithm, Bright streak region was $0.88{\pm}0.49$ g/ml, Dark streak region was $0.63{\pm}0.21$ g/ml, Metal region was $0.06{\pm}0.07$ g/ml, Background was $0.90{\pm}0.02$ g/ml. SUV generally decreased when applying MAR algorithm. In PET image Without MAR algorithm, SUVs of Bright region were higher than those measured in the Background, and it was false positive uptake. But, in PET image with MAR algorithm, SUVs of Bright region were similar to the Background, and false positive uptake disappeared. Conclusion : MAR algorithm could reduce an increase of $^{18}F$-FDG uptake due to attenuation correction in the hip surrounding tissue. However, decrease of SUV in Dark streak region should be considered in the future. Therefore, this study propose that the diagnostic accuracy can be improved in genitourinary diseases adjacent to metallic hip prosthesis, if provided PET images with and Without MAR algorithm, and non attenuation correction images at the same time.

• The Korean Journal of Nuclear Medicine Technology
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• v.28 no.1
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• pp.71-79
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• 2024

Purpose: This study aims to identify SUV, SNR, spatial resolution, and axial uniformity under the same reconstruction conditions and to find out the differences between equipment models. Materials and Methods: The equipment was GE's Discovery 600, 710, IQ, MI(GE Healthcare, USA), and the Phantom used ACR(American College of Radiology) Flangeless Esser Phantom and PET/SPECT Performance Phantom. The PET/SPECT Performance Phantom injected 18F-FDG at a concentration of 3.8 kBq/mL, and the ACR Flangeless Esser Phantom made the conditions for Hot Spot and Background activity for 4 : 1. Image evaluation was compared and evaluated for SUV, SNR, spatial resolution, and axial uniformity with the same reconstruction that added SharpIR of VPHD. Results: The SUV_max showed a difference up to 4.6% with an average of 2.71, 2.35, 1.89, and 1.43 from Hot Spot 1 to 4, and the SUV_mean showed a difference up to 4.7% with 2.06, 1.75, 1.49, and 1.27. There was a difference up to 5% between equipment, and there was no significant difference between both SUV_max and SUV_mean. SNR showed a difference up to 0.04 with an average of 0.37, 0.26, 0.18, and 0.11. FWHM showed a difference up to 0.27. Lastly, COV of axial uniformity was up to 0.018. Conclusion: SUV showed differences within 5% between equipment and showed no significant difference. This is considered to be used as basic data that can be used for the development and replacement of equipment because it has the advantage of being able to observe with a large number of equipment.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.15-28
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• 2019

Purpose Nuclear medicine was initially introduced in Korea in 1969 and widely applied to treat hyperthyroidism with $^{131}I$. Also, gamma camera was adopted in 1969 in the first place and its application has been growing continually in many ways. We analyzed long-term trend in nuclear medicine examinations for the last 2 decades. The purpose of this paper is to make predictions and to set both plans and directions on the development of nuclear medicine. Materials and Methods We analyzed the performance of nuclear medicine examinations and therapies performed in Asan Medical Center from 1998 to 2017. Results Results from the last 20 years regarding Bone scan, Renal scan, MUGA scan and $^{18}F$-FPCIT, Bone Mineral Density were on a increase. And Myocardium perfusion SPECT, Thyroid scan, Lung scan were on a decrease while $^{18}F-FDG$ PET maintained on a steady course. Until 2010 there was a positive performance with the therapy but after the excessive medical care in thyroid examination performance is at status quo. Key events such as a medical strike(2000), Middle-East Respiratory Syndrome (2015) influenced the overall performance of the therapy. Conclusion In order to promote a long-term growth in nuclear medicine examination and therapy, it is inevitable to respond to the changes in current medical environment. Furthermore, it is strongly suggested to put efforts to maintain and develop new examinations and clinical indicators.