title: Measurement of cerebral white matter perfusion using pseudocontinuous arterial spin labeling 3T magnetic resonance imaging--an experimental and theoretical investigation of feasibility.
abstract: OBJECTIVE
  This study was aimed to experimentally and numerically investigate the feasibility of measuring cerebral white matter perfusion using pseudocontinuous arterial spin labeling (PCASL) 3T magnetic resonance imaging (MRI) at a relatively fine resolution to mitigate partial volume effect from gray matter.
  
  
  METHODS
  The Institutional Research Ethics Committee approved this study. On a clinical 3T MR system, ten healthy volunteers (5 females, 5 males, age = 28 ± 3 years) were scanned after providing written informed consent. PCASL imaging was performed with varied combinations of labeling duration (τ = 1000, 1500, 2000, and 2500 ms) and post-labeling delay (PLD = 1000, 1400, 1800, and 2200 ms), at a spatial resolution (1.56 x 1.56 x 5 mm(3)) finer than commonly used (3.5 x 3.5 mm(2), 5-8 mm in thickness). Computer simulations were performed to calculate the achievable perfusion-weighted signal-to-noise ratio at varied τ, PLD, and transit delay.
  
  
  RESULTS
  Based on experimental and numerical data, the optimal τ and PLD were found to be 2000 ms and 1500-1800 ms, respectively, yielding adequate SNR (~2) to support perfusion measurement in the majority (~60%) of white matter. The measurement variability was about 9% in a one-week interval. The measured white matter perfusion and perfusion ratio of gray matter to white matter were 15.8-27.5 ml/100ml/min and 1.8-4.0, respectively, depending on spatial resolution as well as the amount of deep white matter included.
  
  
  CONCLUSIONS
  PCASL 3T MRI is able to measure perfusion in the majority of cerebral white matter at an adequate signal-to-noise ratio by using appropriate tagging duration and post-labeling delay. Although pixel-wise comparison may not be possible, region-of-interest based flow quantification is feasible.
authors: Graduate Institute of Oncology, National Taiwan University, Taipei, Taiwan ; Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan ; Graduate Institute of Clinical Medicine, National Taiwan University, Taipei, Taiwan ; Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
authors: Wen-Chau
authors: WC
authors: Wu
authors: Shu-Chi
authors: SC
authors: Lin
authors: Danny J
authors: DJ
authors: Wang
authors: Kuan-Lin
authors: KL
authors: Chen
authors: Ying-Ding
authors: YD
authors: Li
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply*; D002560:Cerebrovascular Circulation; D003198:Computer Simulation; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D013113:Spin Labels; D013997:Time Factors
chemical_list: D013113:Spin Labels