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Comparison of relative cerebral blood flow maps using pseudo‐continuous arterial spin labeling and single photon emission computed tomography
Author(s) -
Liu Peiying,
Uh Jinsoo,
Devous Michael D.,
Adinoff Bryon,
Lu Hanzhang
Publication year - 2012
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/nbm.1792
Subject(s) - cerebral blood flow , arterial spin labeling , white matter , nuclear medicine , single photon emission computed tomography , medicine , voxel , nuclear magnetic resonance , magnetic resonance imaging , physics , cardiology , radiology
Pseudo‐continuous arterial spin labeling (PCASL) MRI is a relatively new arterial spin labeling technique and has the potential to extend the cerebral blood flow (CBF) measurement to all tissue types, including white matter. However, the arterial transit time ( δ a ) for white matter is not well established and a limited number of reports using multi‐delay methods have yielded inconsistent findings. In this study, we used a different approach and measured white matter δ a (mean ± standard deviation, 1541 ± 173 ms) by determining the arrival times of exogenous contrast agent in a bolus tracking experiment. The data also confirmed δ a of gray matter to be 912 ± 209 ms. In the second part of this study, we used these parameters in PCASL kinetic models and compared relative CBF (rCBF, with respect to the whole brain) maps with those measured using a single photon emission computed tomography (SPECT) technique. It was found that the use of tissue‐specific δ a in the PCASL model was helpful in improving the correspondence between the two modalities. On a regional level, the gray/white matter CBF ratios were 2.47 ± 0.39 and 2.44 ± 0.18 for PCASL and SPECT, respectively. On a single‐voxel level, the variance between the modalities was still considerable, with an average rCBF difference of 0.27. Copyright © 2011 John Wiley & Sons, Ltd.