Artery of Percheron infarct

MRI Brain diffusion with 3D TOF MR Angiogram of Brain

This MRI study shows bilateral foci of recent ischemia with restricted diffusion involving para median thalami and mesencephalic mid brain. Area of involvement corresponds to territory of bilateral thalamo striate perforators arsing from proximal portions of PCA.
On MR Angiogram left PCA particularly the proximal portion show poor flow related signals explains possible involvement of left side thalamo striate perforators but does not explain infarct on right side. Very uncommon for infarcts to develop on either side at the same time ?

An Artery of Percheron is an explanation for this – a normal anatomical variation.

Ok ill try to explain,

Blood supply of thalami is from thalamo striate perforators, which arises from proximal portions of PCAs. Variations related to their origin are, 1^st is each side perforators arising separately from corresponding PCAs ; 2^nd  is perforators arising directly from an arch joining proximal portion of PCA and 3^rd most important one is one of the PCA proximal portion giving a common artery which gives perforator branches to bilateral thalami is called Artery of Percheron occlusion of which can give rise to simultaneous bilateral thalamic infarcts.