Renata F. Leoni1,2, Fernando F. Paiva1, Draulio B. de Araujo2, Afonso C. Silva1
1Cerebral Microcirculation Unit, NINDS, NIH, Bethesda, MD, USA; 2Departamento de Fisica e Matematica, FFCLRP, Universidade de Sao Paulo, Ribeirao Preto, SP, Brazil
Arterial spin labeling (ASL) has been used to measure cerebral blood flow (CBF) noninvasively, and has become useful for the diagnosis of cerebrovascular diseases. Since hypertension is an important risk factor for stroke, CBF maps and perfusion territories were obtained in two groups of spontaneously hypertensive rats (SHR), differing in age, under normo- and hypercapnia using continuous ASL. Reduced CBF and cerebral CO2 reactivity has been observed in the older SHR group, so age can influence the ability of the cerebrovascular system to autoregulate. Moreover, perfusion maps showed asymmetries probably due to anatomic variations of the Circle of Willis.