title: Spatial distribution of white-matter hyperintensities in Alzheimer disease, cerebral amyloid angiopathy, and healthy aging.
abstract: OBJECTIVE
  White-matter hyperintensities (WMHs) detected by magnetic resonance imaging are thought to represent the effects of cerebral small-vessel disease and neurodegenerative changes. We sought to determine whether the spatial distribution of WMHs discriminates between different disease groups and healthy aging individuals and whether these distributions are related to local cerebral perfusion patterns.
  
  
  METHODS
  We examined the pattern of WMHs by T2/fluid-attenuated inversion recovery-weighted magnetic resonance imaging in 3 groups of subjects: cerebral amyloid angiopathy (n=32), Alzheimer disease or mild cognitive impairment (n=41), and healthy aging (n=29). WMH frequency maps were calculated for each group, and spatial distributions were compared by voxel-wise logistic regression. WMHs were also analyzed as a function of normal cerebral perfusion patterns by overlaying a single photon emission computed tomography atlas.
  
  
  RESULTS
  Although WMH volume was greater in cerebral amyloid angiopathy and Alzheimer disease/mild cognitive impairment than in healthy aging, there was no consistent difference in the spatial distributions when controlling for total WMH volume. Hyperintensities were most frequent in the deep periventricular WM in all 3 groups. A strong inverse correlation between hyperintensity frequency and normal perfusion was demonstrated in all groups, demonstrating that WMHs were most common in regions of relatively lower normal cerebral perfusion.
  
  
  CONCLUSIONS
  WMHs show a common distribution pattern and predilection for cerebral WM regions with lower atlas-derived perfusion, regardless of the underlying diagnosis. These data suggest that across diverse disease processes, WM injury may occur in a pattern that reflects underlying tissue properties, such as relative perfusion.
authors.affiliation: Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Holland
authors.forename: Eric E
authors.initials: EE
authors.lastname: Smith
authors.forename: Istvan
authors.initials: I
authors.lastname: Csapo
authors.forename: Mahmut Edip
authors.initials: ME
authors.lastname: Gurol
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Brylka
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Killiany
authors.forename: Deborah
authors.initials: D
authors.lastname: Blacker
authors.forename: Marilyn S
authors.initials: MS
authors.lastname: Albert
authors.forename: Charles R G
authors.initials: CR
authors.lastname: Guttmann
authors.forename: Steven M
authors.initials: SM
authors.lastname: Greenberg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D016657:Cerebral Amyloid Angiopathy / Q000000981:diagnostic imaging / Q000473:pathology*; D002560:Cerebrovascular Circulation; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000000981:diagnostic imaging / Q000473:pathology*; D015899:Tomography, Emission-Computed, Single-Photon