title: Arterial spin labeling of cerebral perfusion territories using a separate labeling coil.
abstract: OBJECTIVE
  To obtain cerebral perfusion territories of the left, the right, and the posterior circulation in humans with high signal-to-noise ratio (SNR) and robust delineation.
  
  
  METHODS
  Continuous arterial spin labeling (CASL) was implemented using a dedicated radio frequency (RF) coil, positioned over the neck, to label the major cerebral feeding arteries in humans. Selective labeling was achieved by flow-driven adiabatic fast passage and by tilting the longitudinal labeling gradient about the Y-axis by theta = +/- 60 degrees .
  
  
  RESULTS
  Mean cerebral blood flow (CBF) values in gray matter (GM) and white matter (WM) were 74 +/- 13 mL . 100 g(-1) . minute(-1) and 14 +/- 13 mL . 100 g(-1) . minute(-1), respectively (N = 14). There were no signal differences between left and right hemispheres when theta = 0 degrees (P > 0.19), indicating efficient labeling of both hemispheres. When theta = +60 degrees , the signal in GM on the left hemisphere, 0.07 +/- 0.06%, was 92% lower than on the right hemisphere, 0.85 +/- 0.30% (P < 1 x 10(-9)), while for theta = -60 degrees , the signal in the right hemisphere, 0.16 +/- 0.13%, was 82% lower than on the contralateral side, 0.89 +/- 0.22% (P < 1 x 10(-10)). Similar attenuations were obtained in WM.
  
  
  CONCLUSIONS
  Clear delineation of the left and right cerebral perfusion territories was obtained, allowing discrimination of the anterior and posterior circulation in each hemisphere.
authors.affiliation: Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, Maryland, USA.
authors.forename: Fernando F
authors.initials: FF
authors.lastname: Paiva
authors.forename: Alberto
authors.initials: A
authors.lastname: Tannús
authors.forename: S Lalith
authors.initials: SL
authors.lastname: Talagala
authors.forename: Afonso C
authors.initials: AC
authors.lastname: Silva
mesh_terms: D000328:Adult; D002536:Cerebral Arteries / Q000033:anatomy & histology*; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography / Q000295:instrumentation*; D008297:Male; D013113:Spin Labels
chemical_list: D013113:Spin Labels