Figure 4.

CT perfusion maps (above) of time-to-peak (TTP) measures in seconds of delay and cerebral blood volume (CBV) in ml/100 cc revealing delayed perfusion via collaterals that have relatively preserved the normal amount of CBV downstream from a right MCA occlusion in a 64-year-old man with left hemiparesis. A heterogeneous pattern of perfusion is noted across different regions of this ischemic territory, due to differences in regional collateral filling. Perfusion angiography images (below) generated from the DSA yields perfusion maps of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and cerebral perfusion pressure (CPP) associated with collateral filling in this right MCA occlusion.