title: Macrovascular and microvascular cerebral blood flow in adults at risk for Alzheimer's disease.
abstract: BACKGROUND
  Capillary hypoperfusion is reported in asymptomatic adults at-risk for Alzheimer's disease (AD), but the extent that can be explained by reduced flow in intracranial arteries is unknown.
  
  
  METHODS
  One hundred fifty-five asymptomatic adults enriched for AD risk (mean age 61 years) completed arterial spin labeling (pcASL) and 4D-flow MRI sequences. Voxel-wise regression models investigated the relationship between mean flow in bilateral cerebral arteries and capillary perfusion, and tested potential moderators of this relationship.
  
  
  RESULTS
  Mean arterial blood flow through middle cerebral arteries (MCAs) and internal carotid arteries was positively associated with perfusion in large cortical clusters (P< .05, false discovery rate corrected). Trends were observed for the interactions MCA flow × age and MCA flow × cardiovascular risk on cerebral perfusion (P< .001, uncorrected).
  
  
  CONCLUSIONS
  These findings provide evidence that capillary perfusion measured via pseudocontinuous arterial spin labeling is strongly dependent on inflow from larger cerebral arteries. Further studies are warranted to investigate possible alterations between macrovascular and microvascular flow in advanced age and elevated cardiovascular risk in asymptomatic adults at risk for AD.
authors.affiliation: Wisconsin Alzheimer's Institute, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Alzheimer's Disease Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Geriatric Research Education and Clinical Center, William. S. Middleton Memorial Veterans Hospital, Madison, WI, USA.
authors.forename: Lindsay R
authors.initials: LR
authors.lastname: Clark
authors.affiliation: Alzheimer's Disease Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Medical Scientist and Neuroscience Training Programs, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
authors.forename: Sara E
authors.initials: SE
authors.lastname: Berman
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
authors.forename: Leonardo A
authors.initials: LA
authors.lastname: Rivera-Rivera
authors.affiliation: Alzheimer's Disease Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
authors.forename: Siobhan M
authors.initials: SM
authors.lastname: Hoscheidt
authors.affiliation: Department of Population Health Sciences, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
authors.forename: Burcu F
authors.initials: BF
authors.lastname: Darst
authors.affiliation: Wisconsin Alzheimer's Institute, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Alzheimer's Disease Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Department of Population Health Sciences, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
authors.forename: Corinne D
authors.initials: CD
authors.lastname: Engelman
authors.affiliation: Alzheimer's Disease Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
authors.forename: Howard A
authors.initials: HA
authors.lastname: Rowley
authors.affiliation: Wisconsin Alzheimer's Institute, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Alzheimer's Disease Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Geriatric Research Education and Clinical Center, William. S. Middleton Memorial Veterans Hospital, Madison, WI, USA.
authors.forename: Cynthia M
authors.initials: CM
authors.lastname: Carlsson
authors.affiliation: Wisconsin Alzheimer's Institute, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Alzheimer's Disease Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Geriatric Research Education and Clinical Center, William. S. Middleton Memorial Veterans Hospital, Madison, WI, USA.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Asthana
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Turski
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
authors.forename: Oliver
authors.initials: O
authors.lastname: Wieben
authors.affiliation: Wisconsin Alzheimer's Institute, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Alzheimer's Disease Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Geriatric Research Education and Clinical Center, William. S. Middleton Memorial Veterans Hospital, Madison, WI, USA.
authors.forename: Sterling C
authors.initials: SC
authors.lastname: Johnson
keywords: Alzheimer's disease; Arterial spin labeling; Cerebral blood flow; Cerebrovascular disease; Phase-contrast MRI; Vascular imaging