Complete duplication of the posterior cerebral artery

Variations of the posterior cerebral artery (PCA) are rare, excluding aplasia or hypoplasia of the P1 segment. To the best of our knowledge, there are few reports of complete duplication of the PCA.

Herein, we report a case of complete duplication of the PCA diagnosed by 1.5 T magnetic resonance angiography.

A 55-year-old woman visited our hospital for cerebrovascular disease screening. Magnetic resonance angiography revealed two right PCAs with similar diameters. One PCA originated as the P1 segment of the PCA branching from the basilar artery, and the other was the fetal-type posterior communicating artery (PCoA) branching from the internal carotid artery (ICA). Neither PCA supplied the right anterior choroidal artery (AChA) territory. Bilateral PCoAs branched from the same position as each ICA, respectively. The right AChA branched from the ICA distal to the PCoA branching position.

Careful imaging assessment is important for identifying complete duplication of the PCA. In addition to the direct findings of AChA identification, the indirect findings of the PCoA branching position and that the PCAs did not supply the AChA territory were also useful for diagnosis in this case.