FIG 2. A very high-grade stenosis of the ICA depicted via 3DRA (A). Tight stenoses such as this could not be directly depicted with CE-MRA, although the presence of downstream contrast and measurable flow provide evidence of residual patency. B, Magnitude (top) and phase (bottom) MR images demonstrating the ICA (arrows) just distal to the stenosis, where the phase image reveals small, but nonzero, flow.