• 제목/요약/키워드: positron

검색결과 696건 처리시간 0.027초

Synthesis of [18F]Fluorocholine Analogues as a Potential Imaging Agent for PET Studies

  • Yu, Kook-Hyun;Park, Jeong-Hoon;Yang, Seung-Dae
    • Bulletin of the Korean Chemical Society
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    • 제25권4호
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    • pp.506-510
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    • 2004
  • There have been intensive studies concerning $[^{11}F]$choline ($[^{11}F]$methyldimethyl( ${\beta}$ -hydroxyethyl) ammonium) (1) which is known as a very effective tracer in imaging various human tumors localized in brain, lung, esophagus, rectum, prostate and urinary bladder using Positron Emission Tomography (PET) and there is increasing interest in $^{18}F$ labelled choline (2) and proved to be useful to visualize prostate cancer. We have prepared six $^{18}F$ labelled alkyl choline derivatives (3a-3c, 4a-4c) from ditosylated and dibrominated alkanes in moderate yields. The six alkyl tosylate or bromate ammonium salts have been synthesized as precursors. Radiofluorination was achieved by the treatment of precursors with $^{18}F$ - in the presence of Kryptofix-2.2.2.. The labeling yields varied ranging from 7 to 25%.

편두통의 기능적 뇌영상 (Functional Neuroimaging in Migraine)

  • 김지현
    • Annals of Clinical Neurophysiology
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    • 제10권1호
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    • pp.13-24
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    • 2008
  • Functional neuroimaging, especially positron emission tomography (PET) and functional magnetic resonance imaging (MRI), is the main tool that allows the unveiling of the neurovascular events during a migraine attack. In migraine with aura, functional neuroimaging has contributed greatly to the understanding of the fundamental pathophysiology of the visual aura, whereas in migraine without aura, the PET findings of brainstem activation suggest a pivotal role of brainstem in the generation of migraine headache. In addition, voxel-based morphometry (VBM) method has provided an insight into the morphometric changes of the brain, which might be considered as a consequence of repeated migraine attacks. In this article, I will briefly discuss the main neuroimaging findings pertaining to the pathophysiology of migraine.

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Variable uterine uptake of FDG in adenomyosis during concurrent chemoradiation therapy for cervical cancer

  • Yu, Jeong-Il;Huh, Seung-Jae;Kim, Young-Il;Kim, Tae-Joong;Park, Byung-Kwan
    • Radiation Oncology Journal
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    • 제29권3호
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    • pp.214-217
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    • 2011
  • To avoid improper tumor volume contouring in radiation therapy (RT) and other invasive procedures, we report a case of uterine adenomyosis showing increased $^{18}F$-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET)/computed tomography (CT) mimicking malignant tumor in a 44-year-old woman during concurrent chemoradiation therapy (CCRT) for uterine cervical cancer. The adenomyosis was not associated with her menstrual cycle or with normal endometrium uptake, and it resolved one month after completion of RT. This case indicates that uterine adenomyosis in a premenopausal woman may show false positive uptake of $^{18}FDG$-PET/CT associated with CCRT.

심근관류 PET (Myocardial Perfusion PET)

  • 조인호;공은정
    • Nuclear Medicine and Molecular Imaging
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    • 제43권3호
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    • pp.207-214
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    • 2009
  • Positron emission tomogrpahy (PET) represents the most advanced scintigraphic imaging technology. With the increase in availability of PET, the clinical use of PET has grown in medical fields. This can be employed for cardiovascular research as well as for clinical applications in patients with various cardiovascular disease. PET allows non-invasive functional assessment of myocardial perfusion, substrate metabolism and cardiac innervation and receptors as well as gene expression in vivo. PET is regarded as the gold standard for the detection of myocardial viability, and it is the only method available for the quantitative assessment of myocardial blood flow. This review focuses on the clinical applications of myocardial perfusion PET in coronary artery disease.

Diagnosis of Graft Infection Using FDG PET-CT

  • Shim, Hun-Bo;Sung, Ki-Ick;Kim, Wook-Sung;Lee, Young-Tak;Park, Pyo-Won;Jeong, Dong-Seop
    • Journal of Chest Surgery
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    • 제45권3호
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    • pp.189-191
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    • 2012
  • Graft infections after aortic replacement are a rare, but severe complication. Because surgical removal of the infection source is essential, an accurate diagnosis is required to prevent unnecessary treatment. Both of the patients described herein were diagnosed with graft infections using dual-modality positron emission tomography-computed tomography; one patient was a false-positive, and the other was confirmed with an infection.

Basic principles and applications of $^{18}F$-FDG-PET/CT in oral and maxillofacial imaging: A pictorial essay

  • Omami, Galal;Tamimi, Dania;Branstetter, Barton F.
    • Imaging Science in Dentistry
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    • 제44권4호
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    • pp.325-332
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    • 2014
  • A combination of positron emission tomography (PET) with $^{18}F$-labeled fluoro-2-deoxyglucose ($^{18}F$-FDG) and computed tomography ($^{18}F$-FDG-PET/CT) has increasingly become a widely used imaging modality for the diagnosis and management of head and neck cancer. On the basis of both recent literature and our professional experience, we present a set of principles with pictorial illustrations and clinical applications of FDG-PET/CT in the evaluation and management planning of squamous cell carcinoma of the oral cavity and oropharynx. We feel that this paper will be of interest and will aid the learning of oral and maxillofacial radiology trainees and practitioners.

도플러 넓어짐 스펙트럼을 이용한 희토류 증감지 결함 특성 (The Defect Characterization of Rare-earth Intensifying Screen Material by Doppler Broadening Positron Annihilation Spectrometer)

  • 이종용;김창규;송기영;김재홍
    • 한국재료학회지
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    • 제15권6호
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    • pp.370-374
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    • 2005
  • Doppler broadening spectrometer for positron annihilation experiment(DBPAS) has been used to characterize nano size defect structures in materials. DBPAS measures the concentration, spatial distribution, and size of open volume defects in the rare-earth intensifying screen materials. The screens were exposed by X-ray varying the exposed doses from 3, 6, 9, and 12 Gy with 6 W and 15 MV respectively and also irradiated by 37 MeV proton beams ranging from 0 to $10^{12}ptls$. The S parameter values increased as the exposed time and the energies increased, which indicated the defects were generated more. The S parameters of the samples with X-rays varied from 0.5098 to 0.5108, on the other hand, as proton beams varied from 0.4804 to 0.4821.

Strain-promoted alkyne-azide cycloaddition for PET molecular imaging study

  • Jeong, Hyeon Jin;Kim, Dong Wook
    • 대한방사성의약품학회지
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    • 제1권1호
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    • pp.15-22
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    • 2015
  • $^{18}F$-labeling reaction of bioactive molecule via click chemistry is widely used to produce $^{18}F$-labeled radiotracer in the field of radiopharmaceutical science and molecular imaging. In particular, bioorthogonal strain-promoted alkyne-azide cycloaddition (SPAAC) reaction has received much attention as an alternative ligation method for radiolabeling bioactive molecules such as peptides, DNA, proteins as well as nanoparticles. Moreover, SPAAC based pretargeting method could provide tumor images successfully on positron emission tomography system using nanoparticle such as mesoporous silica nanoparticles.