Reliability of two-dimensional and three-dimensional pseudo-continuous arterial spin labeling perfusion MRI in elderly populations: comparison with 15O-water positron emission tomography

J Magn Reson Imaging. 2014 Apr;39(4):931-9. doi: 10.1002/jmri.24246. Epub 2013 Sep 13.


Purpose: To investigate the reliability and accuracy of two pseudo-continuous arterial spin labeling (pCASL) sequences, using two-dimensional (2D) gradient-echo echo planar imaging (EPI) and 3D gradient and spin echo (GRASE) as the readout, respectively.

Materials and methods: Each sequence was performed twice 4 weeks apart on six normal control subjects, six elderly subjects with mild cognitive impairment (MCI), and one participant with Alzheimer's disease (AD). Eight of these subjects also underwent H2 (15) O positron emission tomography (PET) scans on the same day or proximal to their second MRI scan. The longitudinal repeatability of EPI and GRASE pCASL were evaluated with the intraclass correlation coefficient (ICC) and within-subject coefficient of variation (wsCV).

Results: The ICCs of global perfusion measurements were 0.697 and 0.413 for GRASE and EPI based pCASL respectively. GRASE pCASL also demonstrated a higher longitudinal repeatability for regional perfusion measurements across 24 regions-of-interests (ICC = 0.707; wsCV = 10.9%) compared with EPI pCASL (ICC = 0.362; wsCV = 15.3%). When compared with PET, EPI pCASL showed a higher degree of spatial correlation with PET than GRASE pCASL, although the difference was not statistically significant.

Conclusion: The 3D GRASE pCASL offers better repeatability than 2D EPI pCASL, thereby may provide a reliable imaging marker for the evaluation of disease progression and treatment effects in MCI and early AD subjects.

Keywords: Alzheimer's disease (AD); arterial spin labeling (ASL); cerebral blood flow (CBF); echo planner imaging (EPI); gradient and spin echo (GRASE); magnetic resonance imaging (MRI); perfusion; positron emission tomography (PET).

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Algorithms
  • Alzheimer Disease / pathology*
  • Brain / pathology*
  • Cognitive Dysfunction / pathology*
  • Female
  • Humans
  • Image Enhancement / methods
  • Image Interpretation, Computer-Assisted / methods
  • Imaging, Three-Dimensional / methods*
  • Magnetic Resonance Angiography / methods*
  • Male
  • Middle Aged
  • Oxygen Radioisotopes
  • Positron-Emission Tomography / methods*
  • Radiopharmaceuticals
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Spin Labels
  • Water*


  • Oxygen Radioisotopes
  • Radiopharmaceuticals
  • Spin Labels
  • Water