Fig 1. VE processing steps in a volunteer. Top, Positioning and orientation of the labeling area on a section of TOF MRA dataset. The labeling area is shown in the first image as the whole section, in the second image as the right (R) and left (L) ICA, and in the third image as ICAs and posterior circulation. Middle, Raw CBF map and reconstruction of separated vascular territories. Bottom, 3-Color selective CBF map is constructed by a combination of the general CBF map with the vascular territory map. Examples of regions of interest present the CBF values and percentages of left, right ICA, and posterior circulation.