Superselective arterial spin labeling applied for flow territory mapping in various cerebrovascular diseases

In three example patients suffering from internal carotid artery occlusion, intracranial steno-occlusive disease, and symptomatic arteriovenous malformation (AVM), a new method named superselective pseudo-continuous arterial spin labeling (pCASL) was used in addition to clinical routine measurements. The capabilities of this method are demonstrated to gain important information in diagnosis, risk analysis, and treatment monitoring that are neither accessible by digital subtraction angiography nor by existing selective arterial spin labeling methods and thus to propose future applications in clinical routine. In all cases superselective pCASL enabled the assessment of tissue viability and of territorial brain perfusion at different levels starting from major brain feeding vessels to collateral circulation at the level of the Circle of Willis to even distal branching arteries. This made it possible to estimate the contribution of an extracranial-intracranial bypass to the brain perfusion; to depict individual arteries to important functional brain areas; to identify en-passant feeding vessels of an AVM and to track possible changes in their perfusion territories after intervention.