From the case: Takayasu arteritis: type I
Axial MR neck angiogram
Narrowing noted at arch level with relative sparing of right brachiocephalic. Right CCA till bifurcation visualized. Left CCA and both vertebral are not visualized. The right distal vertebral is supplied via collaterals. Right ECA and ICA are not clearly made out, collateralization noted at that level. Right ICA is supplied via collaterals. Left ICA shows only retrograde filling.