Location of the investigated regions of interest. Regions of interest are marked with red lines. (A) T₂-weighted image showing regions of interest on the left and right side of regions of the anterior, middle and posterior cerebral circulation. (B) T₂-weighted image showing regions of interest in the right visual cortex. (C) Sagittal T₁-weighted image showing location of axial slices. (D) Cerebral perfusion corresponding to (same slice as) A. The colour bar gives the perfusion values from 0 (bottom) to 120 (top) ml/100 g/min. (E) T₂-weighted image showing region of interest in the right side of the brainstem.