title: Microstructural tissue damage in normal appearing brain tissue accumulates with Framingham Stroke Risk Profile Score: magnetization transfer imaging results of the Austrian Stroke Prevention Study.
abstract: OBJECTIVE
  Magnetization transfer imaging detects cerebral microstructural tissue alterations. We examined the association between the Framingham Stroke Risk Profile (FSRP) score and magnetization transfer imaging (MTI) measures in pathological and normal appearing brain tissue in clinically normal elderly subjects to determine if stroke risk leads to brain tissue destruction beyond what is visible in conventional MRI scans.
  
  
  METHODS
  The study cohort is from the Austrian Stroke Prevention Study (ASPS). A total of 316 subjects underwent MTI and had a complete risk factor assessment sufficient to calculate the FSRP score. There were 205 women and 111 men with a mean age of 70.2 years ranging from 54 to 82 years. Subjects were grouped into four categories of stroke risk probability ranging from 3% to 88% for men and 1% to 84% for women.
  
  
  RESULTS
  A higher FSRP score was significantly and independently associated with a MTR peak position shift indicating global microstructural alterations in brain tissue (BT) and in normal appearing brain tissue (NABT). The mean MTR in white matter hyperintensities (WMH) correlated inversely with increasing stroke risk. Age explained most of the variance in MTR peak position, all other risk factors of the FSRP score contributed significantly but explained an additional 2% of the variance of this MRI measure, only.
  
  
  CONCLUSIONS
  Increasing risk for stroke leads to microstructural brain changes invisible by standard MRI. The validity, the underlying pathogenic mechanisms and the clinical importance of these abnormalities needs to be further determined.
authors.affiliation: Department of Neurology, Division of Special Neurology, Medical University of Graz, Graz, Austria.
authors.forename: Nina
authors.initials: N
authors.lastname: Homayoon
authors.forename: Stefan
authors.initials: S
authors.lastname: Ropele
authors.forename: Edith
authors.initials: E
authors.lastname: Hofer
authors.forename: Petra
authors.initials: P
authors.lastname: Schwingenschuh
authors.forename: Stephan
authors.initials: S
authors.lastname: Seiler
authors.forename: Reinhold
authors.initials: R
authors.lastname: Schmidt
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology; D001317:Austria; D001921:Brain / Q000473:pathology*; D002561:Cerebrovascular Disorders / Q000453:epidemiology; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012307:Risk Factors; D020521:Stroke / Q000473:pathology* / Q000517:prevention & control
keywords: Cerebrovascular risk factors; Magnetic resonance imaging; Magnetization transfer imaging; Stroke