title: Magnetization transfer ratio of white matter hyperintensities in subcortical ischemic vascular dementia.
abstract: OBJECTIVE
  In subjects with subcortical ischemic vascular dementia (SIVD), tissue vacuolization, myelin pallor, and demyelination have been found on pathologic examination of white matter signal hyperintensities (WMSH). Magnetization transfer ratio (MTR) values provide a potential measure of compromised white matter integrity. The purpose of this study was to determine if there were differences in MTR of WMSH between subjects with SIVD and cognitively normal healthy control subjects.
  
  
  METHODS
  Fifteen subjects with SIVD and 16 control subjects of comparable age and sex were studied. MTR images were coregistered to MR images segmented into tissue classes (gray matter, white matter, CSF, WMSH, and lacunar infarcts). MTR of WMSH was compared across groups and examined by WMSH location, size, and total burden.
  
  
  RESULTS
  WMSH burden was greater in SIVD patients than in control subjects (2.4% vs 0.67%). MTR of WMSH did not differ between groups, but MTR of periventricular WMSH was lower in SIVD patients than in control subjects (37.6% vs 39.4%). Even after accounting for covariant effects of lesion burden, there was still a trend toward reduced periventricular WMSH MTR in the group with dementia. There was no correlation between WMSH MTR and WMSH lesion size.
  
  
  CONCLUSIONS
  These findings are consistent with observations that pathologic changes in vascular dementia are most severe in the periventricular white matter and suggest that insight into the pathophysiology of SIVD might be gleaned from studies of the periventricular region.
authors.affiliation: Department of Radiology, New York University Medical Center, New York, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Tanabe
authors.forename: F
authors.initials: F
authors.lastname: Ezekiel
authors.forename: W J
authors.initials: WJ
authors.lastname: Jagust
authors.forename: B R
authors.initials: BR
authors.lastname: Reed
authors.forename: D
authors.initials: D
authors.lastname: Norman
authors.forename: N
authors.initials: N
authors.lastname: Schuff
authors.forename: M W
authors.initials: MW
authors.lastname: Weiner
authors.forename: H
authors.initials: H
authors.lastname: Chui
authors.forename: G
authors.initials: G
authors.lastname: Fein
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology*; D002545:Brain Ischemia / Q000150:complications; D015140:Dementia, Vascular / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male