FIG 1. A, 3D CT angiogram (axial view) and B, MIP image. The left BVR ({blacktriangleup}) typically courses posteriorly after receiving the deep middle cerebral vein. The anterior cerebral vein cannot be identified (A). The right BVR ({triangleup}) is not depicted by 3D CT angiography (A), but is seen by MIP imaging (B)