Doppler haemodynamics of cerebral venous return.

Physiologic functioning of the cerebrovenous system is indispensable for maintaining normal brain function. However, in contrast to the cerebroarterial system, the cerebral venous return is not routinely investigated. Combined high-resolution echo-colour-Doppler (ECD) and transcranial colour coded Doppler sonography (TCCS) represents an ideal method to investigate the haemodynamics of cerebral venous return. TCCS-ECD is noninvasive, repeatable, cost-effective and permits to investigate the cerebral venous outflow in its dependence upon changes in posture and the alternating pressure gradients of the thoracic pump. Several authors reported normal parameters concerning related aspects of cerebral venous return. However, there is no ECD-TCCS standardization of what can be considered a normal venous return. The authors have summarized the current knowledge of the Doppler haemodynamics of the cerebrovenous system and propose a list of reproducible clinical parameters for its sonographic evaluation. In future, the development of this diagnostic technique could be of singular interest in iron-related inflammatory and neurodegenerative disorders like multiple sclerosis.