title: Test-retest variability of adenosine A2A binding in the human brain with (11)C-TMSX and PET.
abstract: BACKGROUND
  The goal of the present study was to evaluate the reproducibility of cerebral adenosine A2A receptor (A2AR) quantification using (11)C-TMSX and PET in a test-retest study.
  
  
  METHODS
  Five healthy volunteers were studied twice. The test-retest variability was assessed for distribution volume (V T) and binding potential relative to non-displaceable uptake (BPND) based on either metabolite-corrected arterial blood sampling or a reference region. The cerebral cortex and centrum semiovale were used as candidate reference regions.
  
  
  RESULTS
  Test-retest variability of V T was good in all regions (6% to 13%). In the putamen, BPND using the centrum semiovale displayed a lower test-retest variability (3%) than that of BPND using the cerebral cortex as a reference region (5%). The noninvasive method showed a higher or similar level of test-retest reproducibility compared to the invasive method.
  
  
  CONCLUSIONS
  Binding reproducibility is sufficient to use (11)C-TMSX as a tool to measure the change in A2AR in the human brain.
authors.affiliation: PET Center, Yale University School of Medicine, 801 Howard Avenue, PO Box 208048, New Haven, CT 06520-8048 USA ; Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, 173-0015 Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Naganawa
authors.affiliation: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, 173-0015 Japan ; Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, 113-0022 Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Mishina
authors.affiliation: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, 173-0015 Japan.
authors.forename: Muneyuki
authors.initials: M
authors.lastname: Sakata
authors.affiliation: Department of Radiological Technology, Faculty of Health Sciences, Hokkaido University of Science, Hokkaido, 006-8585 Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Oda
authors.affiliation: Faculty of Sports and Health Studies, Hosei University, Tokyo, 194-0298 Japan.
authors.forename: Mikio
authors.initials: M
authors.lastname: Hiura
authors.affiliation: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, 173-0015 Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ishii
authors.affiliation: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, 173-0015 Japan.
authors.forename: Kiichi
authors.initials: K
authors.lastname: Ishiwata
keywords: 11C-TMSX; Adenosine A2A receptor; Positron emission tomography; Reproducibility