title: Position dependent changes of the cerebral venous drainage--implications for the imaging of the cervical spine.
abstract: OBJECTIVE
  This study demonstrates the physiological changes of the cerebral venous outflow routes in healthy humans in the recumbent and the sitting position employing positional MRI.
  
  
  METHODS
  In five volunteers, the internal jugular veins and the cervical vertebral plexus were analyzed in the supine and sitting position using an open MR system. Axial T2-weighted scans and axial T1-weighted flow sensitive gradient echo sequences were acquired. The findings were compared to previously published anatomic descriptions from cadaver preparations.
  
  
  RESULTS
  In the supine position, the internal jugular vein is the main route for the cerebral venous outflow. The mean area was 100 mm (2) (±29 mm (2)) for both sides together. In the sitting position, the jugular vein collapses (mean area: 11 mm (2)±2 mm (2)) and the vertebral venous plexus becomes more prominent.
  
  
  CONCLUSIONS
  The position dependent changes in cerebral venous outflow can be imaged using positional MRI. The vertebral venous plexuses may mimic pathologies and physicians reading positional MRI images of the cervical spine should be aware of the physiological changes occurring in the erect position.
authors.affiliation: Privatpraxis für Upright MRT, Radiology, Maternusstraße 44, Köln, Germany. p.niggemann@mrt-koeln.de
authors.forename: P
authors.initials: P
authors.lastname: Niggemann
authors.forename: J
authors.initials: J
authors.lastname: Kuchta
authors.forename: D
authors.initials: D
authors.lastname: Grosskurth
authors.forename: H-K
authors.initials: HK
authors.lastname: Beyer
authors.forename: T
authors.initials: T
authors.lastname: Krings
authors.forename: M
authors.initials: M
authors.lastname: Reinges
mesh_terms: D000328:Adult; D002550:Cerebral Veins / Q000502:physiology*; D002574:Cervical Vertebrae / Q000033:anatomy & histology*; D015916:Drainage, Postural; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007601:Jugular Veins / Q000033:anatomy & histology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011187:Posture / Q000502:physiology*; D013131:Spine / Q000033:anatomy & histology*; D014711:Vertebral Artery / Q000033:anatomy & histology