There are few reports of an accessory anterior cerebral artery (ACA) of duplicate origin. The combination of accessory middle cerebral artery (MCA) and ACA fenestration is also rare.

We report a case of accessory ACA of duplicate origin associated with accessory MCA and ACA fenestration diagnosed by magnetic resonance angiography (MRA).

A 25-year-old woman visited our hospital because of headaches. She underwent 3-Tesla magnetic resonance imaging and MRA, including partial maximum intensity projection and volume rendering images, which showed an accessory ACA originating from the anterior communicating artery. The accessory ACA had two limbs in its proximal portion. Careful assessment revealed a duplicate origin of the accessory ACA. MRA also showed a left accessory MCA arising from the left ACA proximal A1 segment and fenestration of the left ACA distal A1 segment.

Identification of these rare anatomical variants requires careful imaging assessment. In our case, MRA partial maximum intensity projection and volume rendering images were useful and provided a better understanding of the three-dimensional vascular architecture. Although no aneurysms were observed in our case, patients with such anatomical variations should be carefully assessed for associated aneurysms.