Arterial spin labeling in small animals: methods and applications to experimental cerebral ischemia.

ASL enables noninvasive, quantitative monitoring of cerebral perfusion to be performed repeatedly over a period of hours. Thus, ASL is an attractive method for basic science studies of the time evolution and pathophysiology of diseases using animal models. In particular, ASL is valuable for basic science studies of evolving tissue status and viability in stroke using animal models of acute ischemia. This study describes both pulsed (PASL) and continuous ASL (CASL) studies of quantitative cerebral perfusion in rodent models of cerebral ischemia. Some technical factors pertinent to these studies are discussed, including a method for measuring arterial blood T(1) and double-echo PASL for measuring cerebral blood flow (CBF) and volume (CBV). Investigations of the CBF response to forebrain ischemia and reperfusion, and of regional variations in CBF and arterial transit time (ATT) are also discussed.