Cerebrovascular Reserve
Contents
In brief: Cerebrovascular reserve is the brain circulation’s capacity to increase blood flow beyond its resting level.
When arteries are narrowed, downstream vessels may already be maximally dilated. A vasodilatory challenge can then show little increase, or occasionally a paradoxical decrease, in measured flow. Reduced reserve can help connect vascular anatomy with hemodynamic risk.
Use in moyamoya disease
Section titled “Use in moyamoya disease”European expert consensus supports hemodynamic assessment as part of the workup and decision-making process. [1] Reserve may be studied with SPECT, PET, MRI, CT perfusion, transcranial Doppler, or other methods. Protocols, medications, carbon dioxide effects, and delayed collateral arrival influence results. [2]
Clinical detail
Section titled “Clinical detail”Reserve is continuous and territory-specific, not simply normal or abnormal. Thresholds from one method should not be transferred directly to another.