title: Optimal individual inversion time in brain arterial spin labeling perfusion magnetic resonance imaging: correlation with carotid hemodynamics measured with cine phase-contrast magnetic resonance imaging.
abstract: OBJECTIVE
  The quantification of cerebral blood flow using pulsed arterial spin labeling could be erroneous with a nonoptimal inversion time (TI). We suggest that the optimal individual TI is dependent on the hemodynamic values of the supra-aortic vessels.
  
  
  METHODS
  Twenty-two healthy volunteers (mean age, 31.8 years) underwent 7 pulsed arterial spin labeling scans at 3 T with TI ranging from 1200 to 1800 milliseconds every 100 milliseconds. The quantitative hemodynamic values of carotids were computed using a cine phase-contrast sequence. Optimal TIs were determined using visual and quantitative criteria. A correlation was sought between each optimal individual TI criterion and the hemodynamic parameter values.
  
  
  RESULTS
  The optimal group TI was 1700 milliseconds. The individual analysis showed a significant correlation between the optimal TI of white matter signal-to-noise ratio and stroke distance, and the optimal TI of contrast-to-noise ratio with mean velocity.
  
  
  CONCLUSIONS
  A correlation was found between optimal individual TIs and carotid hemodynamic parameters.
authors.affiliation: CHU Rennes, Department of Neuroradiology, Hôpital Pontchaillou, Rennes, France. ean-christophe.ferre@chu-rennes.fr
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Ferré
authors.forename: Jan
authors.initials: J
authors.lastname: Petr
authors.forename: Christian
authors.initials: C
authors.lastname: Barillot
authors.forename: Hélène
authors.initials: H
authors.lastname: Raoult
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Gauvrit
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D013113:Spin Labels; D013382:Subtraction Technique
chemical_list: D013113:Spin Labels