Multiphase CTA images

(A) Images in a patient with a left M1 MCA occlusion (arrow) and good collaterals (backfilling arteries).
(B) Images in a patient with a left M1 MCA occlusion (dashed arrow) and intermediate collaterals.
(C) Images in a patient with a right M1 MCA occlusion (arrowhead) and poor collaterals (minimal backfilling arteries).