Fig 1.

A, 3DRA of the left vertebral artery shows an apparent wide-neck posterior inferior cerebellar artery aneurysm. B, 2D DSA of the left vertebral artery in the same projection as the 3DRA in A shows a cleavage plane distally between the aneurysm and vertebral artery, suggesting that the aneurysm is narrow- rather than wide-neck. C, Postcoil embolization DSA confirms that the neck is accurately depicted by the 2D DSA in B, because the embolization was performed without an assist device and the coils remain contained distally.