title: Measuring the labeling efficiency of pseudocontinuous arterial spin labeling.
abstract: Optimization and validation of a sequence for measuring the labeling efficiency of pseudocontinuous arterial spin labeling (pCASL) perfusion MRI.
  
  
  
  The proposed sequence consists of a labeling module and a single slice Look-Locker echo planar imaging readout. A model-based algorithm was used to calculate labeling efficiency from the signal acquired from the main brain-feeding arteries. Stability of the labeling efficiency measurement was evaluated with regard to the use of cardiac triggering, flow compensation and vein signal suppression. Accuracy of the measurement was assessed by comparing the measured labeling efficiency to mean brain pCASL signal intensity over a wide range of flip angles as applied in the pCASL labeling.
  
  
  
  Simulations show that the proposed algorithm can effectively calculate labeling efficiency when correcting for T1 relaxation of the blood spins. Use of cardiac triggering and vein signal suppression improved stability of the labeling efficiency measurement, while flow compensation resulted in little improvement. The measured labeling efficiency was found to be linearly (R = 0.973; P < 0.001) related to brain pCASL signal intensity over a wide range of pCASL flip angles.
  
  
  
  The optimized labeling efficiency sequence provides robust artery-specific labeling efficiency measurement within a short acquisition time (∼30 s), thereby enabling improved accuracy of pCASL CBF quantification. Magn Reson Med 77:1841-1852, 2017. © 2016 International Society for Magnetic Resonance in Medicine Magn Reson Med 77:1841-1852, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China.
authors.forename: Zhensen
authors.initials: Z
authors.lastname: Chen
authors.affiliation: C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands.|Leiden Institute for Brain and Cognition, Leiden, Netherlands.
authors.forename: Xingxing
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China.|Department of Radiology, University of Washington, Seattle, Washington, USA.
authors.forename: Chun
authors.initials: C
authors.lastname: Yuan
authors.affiliation: Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China.
authors.forename: Xihai
authors.initials: X
authors.lastname: Zhao
authors.affiliation: C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands.|Leiden Institute for Brain and Cognition, Leiden, Netherlands.
authors.forename: Matthias J P
authors.initials: MJP
authors.lastname: van Osch
mesh_terms: D000328:Adult; D000465:Algorithms; D001158:Arteries / Q000000981:diagnostic imaging*; D001921:Brain / Q000098:blood supply; D002536:Cerebral Arteries / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D003198:Computer Simulation; D017352:Echo-Planar Imaging; D005260:Female; D064368:Healthy Volunteers; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D049268:Positron-Emission Tomography; D012815:Signal Processing, Computer-Assisted; D013113:Spin Labels
chemical_list: D013113:Spin Labels
keywords: MRI; arterial spin labeling (ASL); labeling efficiency; perfusion imaging; pseudocontinuous