Inferior Perspective of the Posterior Cerebral Artery

Description

Seen from an inferior aspect, the posterior cerebral artery (PCA) arises from the terminal basilar artery at the level of the interpeduncular fossa, then sweeps posterolaterally around the midbrain. A prominent P1 segment courses from the basilar bifurcation to the posterior communicating artery, after which the P2 segment tracks in the ambient cistern along the lateral midbrain, just inferior to the thalamus and medial to the parahippocampal region. Proximally, the paired PCAs frame the cerebral peduncles, while perforating branches can be inferred entering the posterior perforated substance. Short and direct. This inferior projection is the one you want when teaching the posterior circulation and its cisternal relationships, because it clarifies how the PCA encircles the mesencephalon before turning toward the calcarine and parieto-occipital territories. Infarction in the PCA distribution classically produces contralateral homonymous hemianopia, and involvement of thalamogeniculate perforators or proximal P1 can add thalamic pain syndromes, vertical gaze disturbance, or memory deficits depending on deep territory ischemia. For aneurysm discussions, the PCA origin and the posterior communicating artery junction are key landmarks that can be lost in lateral-only schematics. Use this artwork in neuroanatomy and neuroradiology teaching files to correlate CTA, MRA, and basal cistern anatomy, or in stroke education materials that distinguish basilar tip and PCA occlusion patterns. It also fits operative and endovascular references where residents need a clean map of P1 and P2 for planning approaches through the interpeduncular and ambient cisterns. Anatomical accuracy verified by SciePro's Medical Advisory Board.