Figure 1.

The venous circle (reprinted from 6). 1, anterior cerebral vein;2, anterior communicating vein; 3, olfactory vein;4, inferior frontal vein;5, deep middle cerebral vein;6, inferior striate vein;7, vein of the optic tract;8, hypothalamic vein;9, peduncular vein;10, peduncular perforating vein; 11, transmesencephalic vein; 12, posterior communicating vein; 13, tegmental perforating vein; 14, tectal perforating vein; 15, hippocampal and medial temporal veins;16, uncal vein;17, infratemporal vein.