[Anatomy and variants of the cerebral venous system--fact or defect?].

Unlabelled: The anatomy of the cerebral venous system (CVS) is based on a known variable three-dimensional structure. For a correct recognition and characterization of its elements, a detailed knowledge of its anatomy and potential variants is essential. However, this structural changes, commonly named as variants, may appear in asymptomatic situations as well as associated to certain pathological syndromes with diagnostic and therapeutic consequences.