Validation of a Simple Anatomical Classification Method of the Circle of Willis: A MR Angiographical & Selective Arterial Spin Labeling MRI Study at 3 Tesla

Jeroen Hendrikse¹, Xavier Golay², Esben Thade Petersen³

In this work, we introduce a simple classification method and evaluated its hemodynamic relevance in terms of flow contributions to the anterior and posterior cerebral arteries. Five variants are based on MR angiographic diameter comparisons on the posterior side of the circle of Willis: P1 absent, P1<PCoM, P1=PCoM, P1>PCoM, PCoM absent and on the anterior side: A1 absent, A1<ACoM, A1=ACoM, A1>ACoM, ACoM absent. We correlated the results of our circle of Willis classification method with the perfusion territory contributions of the carotid and vertebrobasilar arteries measured with selective arterial spin labeling (ASL) MRI, in a series of subacute stroke patients.