Imaging and anatomy of the normal intracranial venous system.

The intracranial venous system is a complex three-dimensional structure that is often asymmetric and considerably more variable than the arterial anatomy. The traditional approach has been to evaluate venous phase of catheter angiography. However, non-invasive imaging is now playing a greater role in evaluating the intracranial venous system in both healthy and diseased states. MR angiography, and especially Gd-enhanced 3D MRA, has recently emerged and offers excellent visualization of venous morphology from multiple orientations. An overview of the current non-invasive MRA methods and their applications has been provided during depiction of normal venous anatomy.