Masao Imaizumi

Summary

Affiliation: National Institutes of Health
Country: USA

Publications

  1. ncbi request reprint PET imaging with [11C]PBR28 can localize and quantify upregulated peripheral benzodiazepine receptors associated with cerebral ischemia in rat
    Masao Imaizumi
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 1, Room B3 10, 1 Center Drive, MSC 0135, Bethesda, MD 20892 0135, USA
    Neurosci Lett 411:200-5. 2007
  2. ncbi request reprint Synthesis and evaluation in monkey of two sensitive 11C-labeled aryloxyanilide ligands for imaging brain peripheral benzodiazepine receptors in vivo
    Emmanuelle Briard
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA
    J Med Chem 51:17-30. 2008
  3. pmc Brain and whole-body imaging in nonhuman primates of [11C]PBR28, a promising PET radioligand for peripheral benzodiazepine receptors
    Masao Imaizumi
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bldg 31, Rm B2B37, 31 Center Drive, MSC 2035, Bethesda, MD 20892 2035, USA
    Neuroimage 39:1289-98. 2008
  4. pmc Single-step high-yield radiosynthesis and evaluation of a sensitive 18F-labeled ligand for imaging brain peripheral benzodiazepine receptors with PET
    Emmanuelle Briard
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA
    J Med Chem 52:688-99. 2009
  5. ncbi request reprint Kinetic evaluation in nonhuman primates of two new PET ligands for peripheral benzodiazepine receptors in brain
    Masao Imaizumi
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892 2035, USA
    Synapse 61:595-605. 2007
  6. pmc PET measurement of the in vivo affinity of 11C-(R)-rolipram and the density of its target, phosphodiesterase-4, in the brains of conscious and anesthetized rats
    Tetsuji Itoh
    National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
    J Nucl Med 50:749-56. 2009
  7. pmc Kinetic analysis in healthy humans of a novel positron emission tomography radioligand to image the peripheral benzodiazepine receptor, a potential biomarker for inflammation
    Masahiro Fujita
    Molecular Imaging Branch, National Institute of Mental Health, 31 Center Drive, MSC 2035, Bethesda, MD 20892 2035, USA
    Neuroimage 40:43-52. 2008
  8. ncbi request reprint Radiation dosimetry and biodistribution in monkey and man of 11C-PBR28: a PET radioligand to image inflammation
    Amira K Brown
    Molecular Imaging Branch, National Institute of Mental Health, Bethesda, Maryland 20892 2035, USA
    J Nucl Med 48:2072-9. 2007
  9. ncbi request reprint In vivo and in vitro measurement of brain phosphodiesterase 4 in rats after antidepressant administration
    Masahiro Fujita
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
    Synapse 61:78-86. 2007
  10. pmc Comparison of 18F- and 11C-labeled aryloxyanilide analogs to measure translocator protein in human brain using positron emission tomography
    Leah P Dickstein
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892 1026, USA
    Eur J Nucl Med Mol Imaging 38:352-7. 2011

Collaborators

Detail Information

Publications28

  1. ncbi request reprint PET imaging with [11C]PBR28 can localize and quantify upregulated peripheral benzodiazepine receptors associated with cerebral ischemia in rat
    Masao Imaizumi
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 1, Room B3 10, 1 Center Drive, MSC 0135, Bethesda, MD 20892 0135, USA
    Neurosci Lett 411:200-5. 2007
    ..In this first study to demonstrate neuroinflammation in vivo with small animal PET, [11C]PBR28 had adequate sensitivity to localize and quantify the associated increase in PBRs...
  2. ncbi request reprint Synthesis and evaluation in monkey of two sensitive 11C-labeled aryloxyanilide ligands for imaging brain peripheral benzodiazepine receptors in vivo
    Emmanuelle Briard
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA
    J Med Chem 51:17-30. 2008
    ..11)C] 3 and [ (11)C] 10 are effective for imaging PBR in monkey brain. [ (11)C] 10 especially warrants further evaluation in human subjects...
  3. pmc Brain and whole-body imaging in nonhuman primates of [11C]PBR28, a promising PET radioligand for peripheral benzodiazepine receptors
    Masao Imaizumi
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bldg 31, Rm B2B37, 31 Center Drive, MSC 2035, Bethesda, MD 20892 2035, USA
    Neuroimage 39:1289-98. 2008
    ..The objectives of the current study were to evaluate kinetics of brain uptake, and the influence of the peripheral binding on the arterial input function in rhesus monkey...
  4. pmc Single-step high-yield radiosynthesis and evaluation of a sensitive 18F-labeled ligand for imaging brain peripheral benzodiazepine receptors with PET
    Emmanuelle Briard
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA
    J Med Chem 52:688-99. 2009
    ..In rat, a low level radiometabolite of intermediate lipophilicity was identified as [18F]2-fluoro-N-(2-phenoxyphenyl)acetamide ([18F]11). [18F]9 is a promising radioligand for future imaging of PBR in living human brain...
  5. ncbi request reprint Kinetic evaluation in nonhuman primates of two new PET ligands for peripheral benzodiazepine receptors in brain
    Masao Imaizumi
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892 2035, USA
    Synapse 61:595-605. 2007
    ..A critical factor for human use will be whether the tracer has adequately fast wash out from brain relative to the half-life of the radionuclide to obtain stable values of distribution volume...
  6. pmc PET measurement of the in vivo affinity of 11C-(R)-rolipram and the density of its target, phosphodiesterase-4, in the brains of conscious and anesthetized rats
    Tetsuji Itoh
    National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
    J Nucl Med 50:749-56. 2009
    ..We also studied 2 critical factors in small-animal PET scans: the influence of anesthesia and the difference in binding under in vivo and in vitro conditions...
  7. pmc Kinetic analysis in healthy humans of a novel positron emission tomography radioligand to image the peripheral benzodiazepine receptor, a potential biomarker for inflammation
    Masahiro Fujita
    Molecular Imaging Branch, National Institute of Mental Health, 31 Center Drive, MSC 2035, Bethesda, MD 20892 2035, USA
    Neuroimage 40:43-52. 2008
    ..In conclusion, with the exception of those subjects who appeared to have no PBR binding, [(11)C]PBR28 is a promising ligand to quantify PBRs and localize inflammation associated with increased densities of PBRs...
  8. ncbi request reprint Radiation dosimetry and biodistribution in monkey and man of 11C-PBR28: a PET radioligand to image inflammation
    Amira K Brown
    Molecular Imaging Branch, National Institute of Mental Health, Bethesda, Maryland 20892 2035, USA
    J Nucl Med 48:2072-9. 2007
    ..The aim of this study was to estimate the human radiation doses of (11)C-PBR28 based on biodistribution data in monkeys and humans. In addition, we scanned 1 human subject who fortuitously behaved as if he lacked the PBR binding protein...
  9. ncbi request reprint In vivo and in vitro measurement of brain phosphodiesterase 4 in rats after antidepressant administration
    Masahiro Fujita
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
    Synapse 61:78-86. 2007
    ..g., continuous infusion vs. intermittent injection of antidepressant) in large brain areas. However, the results do not deny possibility of changes in discrete areas, which were not studied in the current study applying PET...
  10. pmc Comparison of 18F- and 11C-labeled aryloxyanilide analogs to measure translocator protein in human brain using positron emission tomography
    Leah P Dickstein
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892 1026, USA
    Eur J Nucl Med Mol Imaging 38:352-7. 2011
    ....
  11. ncbi request reprint PET imaging of the dopamine transporter with 18F-FECNT: a polar radiometabolite confounds brain radioligand measurements
    Sami S Zoghbi
    Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892 0135, USA
    J Nucl Med 47:520-7. 2006
    ....
  12. doi request reprint Increased peripheral benzodiazepine receptors in arterial plaque of patients with atherosclerosis: an autoradiographic study with [(3)H]PK 11195
    Yota Fujimura
    Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA
    Atherosclerosis 201:108-11. 2008
    ..In conclusion, this study demonstrated that macrophage and inflammatory activity in atherosclerotic plaque can be imaged specifically by the binding of PBR indicating future application of PET imaging for PBR...
  13. ncbi request reprint Quantification of brain phosphodiesterase 4 in rat with (R)-[11C]Rolipram-PET
    Masahiro Fujita
    Molecular Imaging Branch, National Institute of Mental Health, Building 1, Room B3 10, 1 Center Drive, MSC 0135, Bethesda, MD 20892 0135, USA
    Neuroimage 26:1201-10. 2005
    ..Phosphodiesterase 4 (PDE4) catabolizes the second messenger 3', 5'-cyclic adenosine monophosphate and may play a critical role in brain diseases. Our aim was to quantify PDE4 in rats with positron emission tomography (PET)...
  14. ncbi request reprint Spectral analysis of 99mTc-HMPAO for estimating cerebral blood flow: a comparison with H2(15)O PET
    Masashi Takasawa
    Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Suita, Japan
    Ann Nucl Med 18:243-9. 2004
    ..The SA method should be especially useful for activation studies involving pharmacological intervention and/or clinical cases with an increased CBF...
  15. ncbi request reprint Interobserver variability of cerebral blood flow measurements obtained using spectral analysis and technetium-99m labeled compounds
    Masashi Takasawa
    Division of Strokology, Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, Suita, Japan
    Ann Nucl Med 17:255-9. 2003
    ..Measurements carried out by two observers using both SA and GA exhibited a similar degree of interobserver variability. SA appears to have a satisfactory interobserver variability and may be more suitable for clinical applications...
  16. ncbi request reprint Statistical image analysis of cerebral blood flow in vascular dementia with small-vessel disease
    Takuya Yoshikawa
    Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine A8, 2 2 Yamadaoka, Suita City, Osaka 565 0871, Japan
    J Nucl Med 44:505-11. 2003
    ..We then evaluated the clinical validity of these techniques for the imaging diagnosis of VaD...
  17. ncbi request reprint Quantification of the heterogeneity of cerebral blood flow in vascular dementia
    Takuya Yoshikawa
    Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine A8, 2 2, Yamadaoka, Suita City, Osaka, 565 0871, Japan
    J Neurol 250:194-200. 2003
    ..In this study, we applied three-dimensional fractal analysis (3D-FA) to CBF SPECT images as a method for assessing the heterogeneity of the cerebral blood flow distribution in VaD. Subjects and..
  18. ncbi request reprint Diastolic blood pressure influences cerebrovascular reactivity measured by means of 123I-iodoamphetamine brain single photon emission computed tomography in medically treated patients with occlusive carotid or middle cerebral artery disease
    Yasuyuki Kimura
    Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, D9, 2 2 Yamadaoka, Suita, Osaka 565 0871, Japan
    Ann Nucl Med 20:209-15. 2006
    ..In these patients, we investigated the possible relationship between the interval change in CVR and that in systemic blood pressure (BP)...
  19. ncbi request reprint Detection of misery perfusion with split-dose 123I-iodoamphetamine single-photon emission computed tomography in patients with carotid occlusive diseases
    Masao Imaizumi
    Division of Tracer Kinetics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
    Stroke 33:2217-23. 2002
    ..In clinical practice, the detection of patients with misery perfusion through the use of widely available, noninvasive, and cost-effective modalities such as single-photon emission computed tomography (SPECT) is extremely important...
  20. ncbi request reprint Automatic determination of brain perfusion index for measurement of cerebral blood flow using spectral analysis and 99mTc-HMPAO
    Masashi Takasawa
    Division of Strokology, Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, 2 2, Yamadaoka, Suita City, Japan
    Eur J Nucl Med Mol Imaging 29:1443-6. 2002
    ..21 x-0.0075, r=0.800). Our results suggest that this automatic SA method provides an accurate estimate of BPI that can be used for the quantification of CBF using (99m)Tc-HMPAO SA...
  21. ncbi request reprint Cerebral and cerebellar activation in power and precision grip movements: an H2 15O positron emission tomography study
    Masashi Takasawa
    Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Osaka, Japan
    J Cereb Blood Flow Metab 23:1378-82. 2003
    ..Our findings indicate no difference in brain activation between the acts of power grip and precision grip without a target object...
  22. ncbi request reprint Cortical processing of tactile language in a postlingually deaf-blind subject
    Yasuhiro Osaki
    Department of Otorhinolaryngology, Osaka University School of Medicine, 2 2 Yamadaoka, Suita, Osaka 565 0871, Japan
    Neuroreport 15:287-91. 2004
    ..Our results demonstrated that the deaf-blind subject is heavily involved in interpreting tactile language by enhancing cortical activation of cognitive and semantic processing...
  23. ncbi request reprint Cerebral hemodynamics and metabolism in adult moyamoya disease: comparison of angiographic collateral circulation
    Rishu Piao
    Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, Suita, Japan
    Ann Nucl Med 18:115-21. 2004
    ..The aim of the present study was to evaluate the hemodynamic and metabolic status in relation to the development of basal moyamoya vessels (BMVs)...
  24. ncbi request reprint Clinical significance of cerebrovascular reserve in acetazolamide challenge -comparison with acetazolamide challenge H2O-PET and Gas-PET
    Masao Imaizumi
    Division of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Japan
    Ann Nucl Med 18:369-74. 2004
    ..However, how precisely ACZ reflects cerebral hemodynamic impairment remains obscure. The present study aims to clarify the pathological significance of CVR in patients with occluded carotid arteries...
  25. ncbi request reprint Hemodynamic influences of losartan on the brain in hypertensive patients
    Naohiko Oku
    Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Osaka, Japan
    Hypertens Res 28:43-9. 2005
    ..The inclusion of losartan in anti-hypertensive regimens could be advantageous for cerebral circulation in patients with essential hypertension...
  26. ncbi request reprint Critical analysis of hemodynamic insufficiency by head-up tilt in patients with carotid occlusive disease
    Manabu Sakaguchi
    Division of Strokology, Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
    Circ J 69:971-5. 2005
    ....
  27. ncbi request reprint Neural mechanism of residual inhibition of tinnitus in cochlear implant users
    Yasuhiro Osaki
    Department of Otorhinolaryngology and Sensory Organ Surgery, Osaka University Graduate School of Medicine, Japan
    Neuroreport 16:1625-8. 2005
    ..No significant activation was observed in the normal controls. Our results suggest that tinnitus and residual inhibition are related to cortical networks of auditory higher-order processing, memory and attention...
  28. ncbi request reprint Assessment of acetazolamide reactivity in cerebral blood flow using spectral analysis and technetium-99m hexamethylpropylene amine oxime
    Masashi Takasawa
    Division of Strokology, Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, Japan
    J Cereb Blood Flow Metab 22:1004-9. 2002
    ..3 +/- 6.5% according to the BPIG values. These results suggest that the spectral analysis of 99mTc-HMPAO-generated data yields a more reliable BPI than GA for the quantification of CBF after acetazolamide administration...