CBF measurements using multidelay pseudocontinuous and velocity-selective arterial spin labeling in patients with long arterial transit delays: comparison with xenon CT CBF.

Publication Type	Academic Article
Authors	Qiu D, Straka M, Zun Z, Bammer R, Moseley M, Zaharchuk G
Journal	J Magn Reson Imaging
Volume	36
Issue	1
Pagination	110-9
Date Published	02/22/2012
ISSN	1522-2586
Keywords	Cerebrovascular Circulation, Magnetic Resonance Angiography, Moyamoya Disease, Tomography, X-Ray Computed, Xenon
Abstract	PURPOSE: To test the theory that velocity-selective arterial spin labeling (VSASL) is insensitive to transit delay. MATERIALS AND METHODS: Cerebral blood flow (CBF) was measured in ten Moyamoya disease patients using xenon computed tomography (xeCT) and magnetic resonance imaging (MRI), which included multiple pseudo-continuous ASL (pcASL) with different postlabel delays, VSASL, and dynamic susceptibility contrast (DSC) imaging. Correlation coefficient, root-mean-square difference, mean CBF error between ASL, and gold-standard xeCT CBF measurements as well the dependence of this error on transit delay (TD) as estimated by DSC time-to-peak of the residue function (Tmax) were determined. RESULTS: For pcASL with different postlabel delay time (PLD), CBF measurement with short PLD (1.5-2 sec) had the strongest correlations with xeCT; VSASL had a lower but still significant correlation with a mean coefficient of 0.55. We noted the theoretically predicted dependence of CBF error on Tmax and on PLD for pcASL; VSASL CBF measurements had the least dependence of the error on TD. We also noted effects suggesting that the location of the label decay (blood vs. tissue) impacted the measurement, which was worse for pcASL than for VSASL. CONCLUSION: We conclude that VSASL is less sensitive to TD than conventional ASL techniques and holds promise for CBF measurements in cerebrovascular diseases with slow flow.
DOI	10.1002/jmri.23613
PubMed ID	22359345
PubMed Central ID	PMC3368036