FIG 3. A 46-year-old man with presyncope and right upper extremity weakness.

A, CE MRA MIP image (3D FLASH, TR/TE, 4.36/1.64; flip angle 25°; bandwith, 432 Hz; matrix 136 x 512; field of view, 165 x 330 mm; slab thickness, 70 mm; partitions, 80; and voxel size, 1.33 x 0.64 x 1.15 mm³) of the vertebrobasilar system shows segmental occlusion of the proximal right vertebral artery (open arrow), as well as diffuse narrowing superior to the occluded segment (small arrows).

B, Selective DSA of the right subclavian confirms occlusion (open arrow) and stenosis (closed arrows) in proximal right vertebral artery.