RT Journal Article
SR Electronic
T1 Potentials and Challenges for Arterial Spin Labeling in Pharmacological Magnetic Resonance Imaging
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 359
OP 366
DO 10.1124/jpet.110.172577
VO 337
IS 2
A1 Danny J. J. Wang
A1 Yufen Chen
A1 María A. Fernández-Seara
A1 John A. Detre
YR 2011
UL http://jpet.aspetjournals.org/content/337/2/359.abstract
AB Pharmacological magnetic resonance imaging (phMRI) is increasingly being used in drug discovery and development to speed the translation from the laboratory to the clinic. The two primary methods in phMRI include blood-oxygen-level-dependent (BOLD) contrast and arterial spin-labeled (ASL) perfusion MRI. BOLD contrast has been widely applied in existing phMRI studies. However, because of the lack of absolute quantification and poor reproducibility over time scales longer than hours or across scanning sessions, BOLD fMRI may not be suitable to track oral and other long-term drug effects on baseline brain function. As an alternative method, ASL provides noninvasive, absolute quantification of cerebral blood flow both at rest and during task activation. ASL perfusion measurements have been shown to be highly reproducible over minutes and hours to days and weeks. These two characteristics make ASL an ideal tool for phMRI for studying both intravenous and oral drug action as well as understanding drug effects on baseline brain function and brain activation to cognitive or sensory processing. When ASL is combined with BOLD fMRI, drug-induced changes in cerebral metabolic rate of oxygen may also be inferred. Representative phMRI studies using ASL perfusion MRI on caffeine, remifentanil, and metoclopramide (dopamine antagonist) are reviewed here, with an emphasis on the methodologies used to control for potentially confounding vascular and systemic effects. Both the potentials and limitations of using ASL as an imaging marker of drug action are discussed.