FIG 5. Images in animal 4. Top row, CBV, MTT, and CBF maps from the control preocclusion study. Middle row, Results from the study obtained 30 minutes after the start of occlusion. The right MCA territorial hypoperfusion is clearly visible after occlusion. Bottom row, Examples of ROIs representing the lesion on the maps. The lesion is larger on the MTT map than on the CBV and CBF maps. This is likely due to the presence of collateral circulation that results in normal perfusion on the CBV and CBF maps but prolonged transit time. Each image is individually windowed to facilitate presentation of the lesion.