Fig. 3

A 73-year old woman presented with sudden onset of left hemiplegia. In addition to non-contrast CT brain and CT angiography of the craniocervical arteries, CT perfusion was performed because of the uncertainty of time of symptom onset. The presented source images are images at consecutive time intervals. Source image at early arterial phase (a) shows discrete contrast filling into temporal M2 and proximal M3 branches at the normal left side (encircled). At the right side, there is only filling of the proximal middle cerebral artery with slight contrast penetration past the thrombus, but no contrast at the level of more distal M2 segment or proximal M3 segments. Source image in the later arterial phase (b, 4.5 s after a) shows almost symmetrical filling of distal arterial branches of both hemispheres. The short occlusion at distal M1 segment (long arrow) is better appreciated. The central cerebral veins are symmetrically opacified (encircled). There is already filling of the right superficial middle cerebral vein (short arrow), but persisting asymmetry in opacification of the cortical veins is observed. In late venous phase (c, 6 s after a), source image centered at a more cranial level shows symmetrical cortical vein opacification. Because of deemed adequate collateral vascular status and large penumbra/infarct mismatch at perfusion imaging (not shown), subsequently, the patient underwent successful retrieval of a small thrombus. Almost immediately after the procedure, a good clinical recovery occurred with uneventful post EVT clinical course