Fig 1.

47-year-old woman presenting with quadranopsia.

A, Axial FLAIR image demonstrating hyperintensity in the right cerebral peduncle.

B, Axial diffusion-weighted image (DWI) image showing corresponding abnormal increased signal intensity. There was respective low signal intensity on the apparent diffusion coefficient map (not shown).

C, DSA, left vertebral artery injection, transfacial view, demonstrates a smoothly tapered focal, near-occlusive narrowing of the proximal right PCA.

D, DSA, left vertebral artery injection, transfacial view. One-year follow-up demonstrating a “double lumen” sign of the right P2 segment.

E, 3D reconstruction of left vertebral angiogram rotational DSA which shows 2 patent lumens (double lumen sign) distal to the posterior communicating artery (arrowhead). Note the irregularly recanalized false lumen (arrow) with 2 separate inflow channels.