title: Hemodynamic alterations in vertebrobasilar large artery disease assessed by arterial spin-labeling MR imaging.
abstract: OBJECTIVE
  VB artery stenosis is associated with a high risk of recurrent ischemic events, and knowledge about the hemodynamic relevance of VB stenosis is important for clinical decision making. In this study, multiple inflow pulsed ASL MR imaging was assessed for its ability to measure CBF and ATT in patients with VB disease.
  
  
  METHODS
  ASL was performed on a 3T MR imaging scanner in 41 participants. Twenty-one patients had a history of ischemic events in the VB circulation (14 men, 7 women, age 66 ± 11 years). Clinical data and CE-MRA were used to classify VB disease severity. Twenty age-matched adults were controls. Group and within-VB analyses were performed. Mean CBF and ATT values in the ROIs were adjusted by excluding voxels that did not produce a reliable ASL estimate.
  
  
  RESULTS
  CBF was reduced (P < .003) in patients compared with controls, which was significant after excluding voxels with a poor fit. Differences in ATT between patients and controls were not significant after voxel correction. There was a strong correlation between CBF and ATT among patients. Finally, ATT was significantly correlated with VB disease severity (P = .026).
  
  
  CONCLUSIONS
  Multiple inflow ASL distinguished patients with VB disease from age matched-controls. VB disease rating was associated with prolonged ATT downstream. ASL may have diagnostic potential among patients in whom risk of intervention is high.
authors.affiliation: Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, England. bmac@sri.utoronto.ca
authors.forename: B J
authors.initials: BJ
authors.lastname: Macintosh
authors.forename: L
authors.initials: L
authors.lastname: Marquardt
authors.forename: U G
authors.initials: UG
authors.lastname: Schulz
authors.forename: P
authors.initials: P
authors.lastname: Jezzard
authors.forename: P M
authors.initials: PM
authors.lastname: Rothwell
mesh_terms: D000368:Aged; D000465:Algorithms; D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels; D014715:Vertebrobasilar Insufficiency / Q000473:pathology* / Q000503:physiopathology*
chemical_list: D013113:Spin Labels