Cerebral perfusion and arterial transit time changes during task activation determined with continuous arterial spin labeling.
Perfusion imaging by arterial spin labeling (ASL) can be highly sensitive to the transit time from the labeling site to the tissue. We report the results of a study designed to separate the transit time and perfusion contributions to activation in ASL images accompanying motor and visual stimulation. Fractional transit time decreases were found to be comparable to fractional perfusion increases and the transit time change was found to be the greatest contributor to ASL signal change in ASL sequences without delayed acquisition. The implications for activation imaging with ASL and the arterial control of flow are discussed.
Gonzalez-At
J B
JB
Departments of Neurology and Radiology, University of Pennsylvania, Philadelphia, PA 19104-4283, USA.
Alsop
D C
DC
Detre
J A
JA
D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods*; D013113:Spin Labels
D013113:Spin Labels