FIG 2. F and G, Lateral views of early arterial (F) and capillary (G) phases of left vertebral angiogram show high-grade stenosis of the mid-basilar artery (arrow, F) and retrograde filling of the pericallosal artery (arrows, G) via PCA collaterals.

H, Anteroposterior view of left vertebral angiogram shows an occluded right PCA.

I, Anteroposterior view of right ICA angiogram after right MCA angioplasty shows almost complete resolution of the right MCA stenosis