FIG 1. Anteroposterior projection left vertebral catheter injection digital subtraction angiogram shows hypertrophy of several posterior choroidal branches (arrow) arising from the right posterior cerebral artery and supplying a mural-type vein of Galen malformation. The malformation is also fed in a retrograde fashion from the left posterior communicating artery. Note wash-in of unopacified blood (arrowhead) retrograde from the P1 segment of the left posterior cerebral artery.