The cerebral circulation has unique characteristics. Among them, the cerebral vasoreactivity is responsible for maintaining the blood flow relatively stable despite variations in blood pressure, and changing it in response to functional needs, allowing a delicate control of the relationship between functional activity, metabolism and blood flow in brain tissue. Patients with cerebrovascular diseases, such as carotid stenosis, have a deficit of cerebral vasoreactivity, which can lead to ischemic stroke. Therefore, due to the great relevance in clinical practice, we aim to assess the cerebral vasoreactivi-ty and vascular reserve in patients with severe carotid stenosis, and correlate the results with the existence of collateral flow to be evaluated by transcranial Doppler and mag-netic resonance angiography. The arterial spin labeling (ASL) technique will be used to quantitatively obtain the baseline cerebral blood flow and its changes after vasodilator stimulation by inhalation of CO2. In addition, ASL will be used to map the perfusion territories of the major cerebral arteries, which will be useful in the evaluation of colla-teral flow. Thus, this project aims to implement ASL in the MRI service of the Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto (HC-FMRP), and use it to quan-tify the baseline cerebral blood flow, cerebrovascular reactivity to hypercapnia, and collateral flow through the vascular territory mapping in patients with severe carotid stenosis.
News published in Agência FAPESP Newsletter about the scholarship: