title: Application of magnetization transfer at 3.0 T in three-dimensional time-of-flight magnetic resonance angiography of the intracranial arteries.
abstract: OBJECTIVE
  To apply magnetization transfer (MT) at 3.0 T in three-dimensional time-of-flight magnetic resonance angiography of the intracranial arteries.
  
  
  METHODS
  This study was performed on phantoms and seven volunteers to determine the effects of MT at 3.0 T. By using a modulated MT approach and an altered phase encode order, the specific absorption rate (SAR) was kept below 3 W/kg over any 8-second time period.
  
  
  RESULTS
  For a 20-degree flip angle and 36 msec repetition time, the background suppression at 3.0 T was improved with MT by 52 +/- 5% for white matter and 40 +/- 8% for grey matter, making the distal intracranial vasculature significantly more discernible.
  
  
  CONCLUSIONS
  MT at 3.0 T can significantly improve background suppression in 3D time-of-flight magnetic resonance angiography (MRA) of the intracranial arteries without exceeding SAR guidelines.
authors.affiliation: Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Thomas
authors.forename: Osama
authors.initials: O
authors.lastname: Al-Kwifi
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Emery
authors.forename: Alan H
authors.initials: AH
authors.lastname: Wilman
mesh_terms: D000328:Adult; D002536:Cerebral Arteries / Q000033:anatomy & histology*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D019047:Phantoms, Imaging