Visualizing Artery-Specific Blood Flow Patterns Above the Circle of Willis with Vessel-Encoded Arterial Spin Labeling

Thomas W. Okell¹, Michael A. Chappell, ¹², Peter Jezzard¹

Vessel-encoded pseudocontinuous arterial spin labeling (VEPCASL) is typically used to generate artery-specific perfusion maps of three or four brain-feeding arteries. The ability to label a larger number of vessels may be useful for assessing flow patterns in smaller arteries, such as those supplying an arteriovenous malformation. Here we encode thirteen arteries (nine intracranial, four extracranial) above the circle of Willis in healthy volunteers using both dynamic angiographic and perfusion-weighted readouts. The Bayesian analysis method used successfully separates all vascular components. The resulting artery-specific images reveal blood flow patterns and hemodynamics within the vessels along with the resulting downstream perfusion.