Bilateral carotid and vertebral rete mirabile presenting with subarachnoid hemorrhage caused by the rupture of spinal artery aneurysm.

Rete mirabile (or carotid rete) is a normal structure that plays physiological roles in the lower mammals. However, the rete does not exist in the normal carotid circulation of humans. Carotid rete mirabile (CRM) is a rare condition compensating for congenital dysplastic internal carotid artery.