title: Test-retest reliability of arterial spin labeling with common labeling strategies.
abstract: OBJECTIVE
  To compare the test-retest reproducibility of three variants of arterial spin labeling (ASL): pseudo-continuous (pCASL), pulsed (PASL) and continuous (CASL).
  
  
  METHODS
  Twelve healthy subjects were scanned on a 3.0T scanner with PASL, CASL, and pCASL. Scans were repeated within-session, after 1 hour, and after 1 week to assess reproducibility at different scan intervals.
  
  
  RESULTS
  Comparison of within-subject coefficients of variation (wsCV) demonstrated high within-session reproducibility (ie, low wsCV) for CASL-based methods (gray matter [GM] wsCV for pCASL: 3.5% ± 0.02%, CASL: 4.1% ± 0.07%) compared to PASL (wsCV: 7.5% ± 0.06%), due to the higher signal-to-noise ratio (SNR) associated with continuous labeling, evident in the 20% gain in temporal SNR and 58% gain in raw SNR for pCASL relative to PASL. At the 1-week scan interval, comparable reproducibility between PASL (GM wsCV 9.2% ± 0.12%) and pCASL (GM wsCV 8.5% ± 0.14%) was observed, indicating the dominance of physiological fluctuations.
  
  
  CONCLUSIONS
  Although all three approaches are capable of measuring cerebral blood flow within a few minutes of scanning, the high precision and SNR of pCASL, with its insensitivity to vessel geometry, make it an appealing method for future ASL application studies.
authors: Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA.
authors: Yufen
authors: Y
authors: Chen
authors: Danny J J
authors: DJ
authors: Wang
authors: John A
authors: JA
authors: Detre
mesh_terms: D000328:Adult; D000465:Algorithms; D001158:Arteries / Q000473:pathology; D001921:Brain / Q000473:pathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D015233:Models, Statistical; D015203:Reproducibility of Results; D013113:Spin Labels
chemical_list: D013113:Spin Labels