title: Positron Emission Tomographic Imaging in Stroke: Cross-Sectional and Follow-Up Assessment of Amyloid in Ischemic Stroke.
abstract: OBJECTIVE
  Cardiovascular risk factors significantly increase the risk of developing Alzheimer disease. A possible mechanism may be via ischemic infarction-driving amyloid deposition. We conducted a study to determine the presence of β-amyloid in infarct, peri-infarct, and hemispheric areas after stroke. We hypothesized that an infarct would trigger β-amyloid deposition, with deposition over time.
  
  
  METHODS
  Patients were recruited within 40 days of acute ischemic stroke and imaged with computed tomographic or magnetic resonance imaging and Pittsburgh compound B (11C-PiB) positron emission tomographic scans. Follow-up positron emission tomographic scanning was performed in a subgroup ≤18 months after the stroke event. Standardized uptake value ratios for regions of interest were analyzed after coregistration.
  
  
  RESULTS
  Forty-seven patients were imaged with (11)C-PiB positron emission tomography. There was an increase in (11)C-PiB accumulation in the stroke area compared with a reference region in the contralesional hemisphere, which was not statistically significant (median difference in standardized uptake value ratio, 0.07 [95% confidence interval, -0.06 to 0.123]; P=0.452). There was no significant increase in the accumulation of (11)C-PiB in the peri-infarct region or in the ipsilesional hemisphere (median difference in standardized uptake value ratio, 0.04 [95% confidence interval, -0.02 to 0.10]; P=0.095). We repeated (11)C-PiB positron emission tomography in 21 patients and found a significant reduction in accumulation of (11)C-PiB between regions of interest (median difference in standardized uptake value ratio, -0.08 [95% confidence interval, -0.23 to -0.03]; P=0.04).
  
  
  CONCLUSIONS
  There was no significant increase in (11)C-PiB accumulation in or around the infarct. There was no increase in ipsilesional hemispheric (11)C-PiB accumulation over time. We found no evidence that infarction leads to sustained or increased β-amyloid deposition ≤18 months after stroke.
authors.affiliation: From the Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia (R.S., T.L., L.C., J.V.L., G.D., A.D.); University of Melbourne, Victoria, Australia (R.S., V.L.V., L.C., J.V.L., C.R., G.D., A.D.); Universiti Kebangsaan Malaysia Medical Centre, Bangi, Malaysia (R.S.); Gothenburg University, Gothenburg, Sweden (T.L.); and Austin Hospital PET Centre, Melbourne, Victoria, Australia (V.L.V., C.R.).
authors.forename: Ramesh
authors.initials: R
authors.lastname: Sahathevan
authors.affiliation: From the Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia (R.S., T.L., L.C., J.V.L., G.D., A.D.); University of Melbourne, Victoria, Australia (R.S., V.L.V., L.C., J.V.L., C.R., G.D., A.D.); Universiti Kebangsaan Malaysia Medical Centre, Bangi, Malaysia (R.S.); Gothenburg University, Gothenburg, Sweden (T.L.); and Austin Hospital PET Centre, Melbourne, Victoria, Australia (V.L.V., C.R.).
authors.forename: Thomas
authors.initials: T
authors.lastname: Linden
authors.affiliation: From the Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia (R.S., T.L., L.C., J.V.L., G.D., A.D.); University of Melbourne, Victoria, Australia (R.S., V.L.V., L.C., J.V.L., C.R., G.D., A.D.); Universiti Kebangsaan Malaysia Medical Centre, Bangi, Malaysia (R.S.); Gothenburg University, Gothenburg, Sweden (T.L.); and Austin Hospital PET Centre, Melbourne, Victoria, Australia (V.L.V., C.R.).
authors.forename: Victor L
authors.initials: VL
authors.lastname: Villemagne
authors.affiliation: From the Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia (R.S., T.L., L.C., J.V.L., G.D., A.D.); University of Melbourne, Victoria, Australia (R.S., V.L.V., L.C., J.V.L., C.R., G.D., A.D.); Universiti Kebangsaan Malaysia Medical Centre, Bangi, Malaysia (R.S.); Gothenburg University, Gothenburg, Sweden (T.L.); and Austin Hospital PET Centre, Melbourne, Victoria, Australia (V.L.V., C.R.).
authors.forename: Leonid
authors.initials: L
authors.lastname: Churilov
authors.affiliation: From the Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia (R.S., T.L., L.C., J.V.L., G.D., A.D.); University of Melbourne, Victoria, Australia (R.S., V.L.V., L.C., J.V.L., C.R., G.D., A.D.); Universiti Kebangsaan Malaysia Medical Centre, Bangi, Malaysia (R.S.); Gothenburg University, Gothenburg, Sweden (T.L.); and Austin Hospital PET Centre, Melbourne, Victoria, Australia (V.L.V., C.R.).
authors.forename: John V
authors.initials: JV
authors.lastname: Ly
authors.affiliation: From the Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia (R.S., T.L., L.C., J.V.L., G.D., A.D.); University of Melbourne, Victoria, Australia (R.S., V.L.V., L.C., J.V.L., C.R., G.D., A.D.); Universiti Kebangsaan Malaysia Medical Centre, Bangi, Malaysia (R.S.); Gothenburg University, Gothenburg, Sweden (T.L.); and Austin Hospital PET Centre, Melbourne, Victoria, Australia (V.L.V., C.R.).
authors.forename: Christopher
authors.initials: C
authors.lastname: Rowe
authors.affiliation: From the Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia (R.S., T.L., L.C., J.V.L., G.D., A.D.); University of Melbourne, Victoria, Australia (R.S., V.L.V., L.C., J.V.L., C.R., G.D., A.D.); Universiti Kebangsaan Malaysia Medical Centre, Bangi, Malaysia (R.S.); Gothenburg University, Gothenburg, Sweden (T.L.); and Austin Hospital PET Centre, Melbourne, Victoria, Australia (V.L.V., C.R.).
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Donnan
authors.affiliation: From the Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia (R.S., T.L., L.C., J.V.L., G.D., A.D.); University of Melbourne, Victoria, Australia (R.S., V.L.V., L.C., J.V.L., C.R., G.D., A.D.); Universiti Kebangsaan Malaysia Medical Centre, Bangi, Malaysia (R.S.); Gothenburg University, Gothenburg, Sweden (T.L.); and Austin Hospital PET Centre, Melbourne, Victoria, Australia (V.L.V., C.R.). agbrod@unimelb.edu.au.
authors.forename: Amy
authors.initials: A
authors.lastname: Brodtmann
mesh_terms: D000368:Aged; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000639:trends*; D012307:Risk Factors; D020521:Stroke / Q000000981:diagnostic imaging* / Q000378:metabolism*
chemical_list: D016229:Amyloid beta-Peptides
keywords: Alzheimer disease; follow-up studies; positron emission tomography; risk factors