Fig. 2

Angiographic findings suggestive of occlusion of right artery of Percheron. Contrast-enhanced magnetic resonance imaging (a) and CT angiogram (c) demonstrated normal opacification and diameter of the vertebrobasilar arterial trunk, excluding top of the basilar artery syndrome. There was slight asymmetry of the posterior cerebral arteries (PCAs) with relative narrowing of the right P1 segment compared to the left (yellow arrows in a and c), raising the possibility of incomplete P1 occlusion or stenosis and occlusion at the level of the perforating branches of the right PCA, namely artery of Percheron. However, the filling of the more distal part of the right PCA appeared normal, likely due to the contribution from a robust posterior communicating artery (yellow arrows in b). Magnetic resonance venogram (d) demonstrated normal opacification and filling of the internal cerebral veins (yellow arrows) and intracranial venous sinuses, excluding deep cerebral venous infarct