title: [Virtual MR endoscopy of the ventricles prior to neurosurgical interventional endoscopy -- evaluation of different presentation techniques].
abstract: OBJECTIVE
  In the past, virtual endoscopies have been performed for planning of endoscopic interventions or for diagnostic purposes in various organ systems with increasing frequency. This study evaluates the ability of virtual ventricular endoscopy to depict anatomical structures and the use for planning of real endoscopy.
  
  
  METHODS
  In a prospective study, 4 volunteers and 8 patients were examined with MRI. In 3 of the patients endoscopy was performed by our neurosurgeons thereafter. The calculation of the virtual endoscopy was based on 1 mm sagittal T2-weighted images. Comparison of surface rendering and volume rendering was made by means of video sequencing of individual views, and these were compared with the intraoperative endoscopic videos concerning the depictability of anatomical landmarks.
  
  
  RESULTS
  The reconstructions using volume rendering were more significant and easier to calculate than those based on surface rendering. Virtual endoscopy in the transparent mode allowed visualization of hazardous structures outside the ventricular system such as the basilar artery tip. Transparent 3D images of the ventricles gave a good overview on the depicted structures and enabled a better orientation during the virtual camera flight than surface rendered views.
  
  
  CONCLUSIONS
  MR-based virtual endoscopy of the ventricular system can be obtained on the basis of surface- and volume-rendered views of sagittal T2-weighted thin sections. Preoperative utilization of this method simplifies the planning of endoscopy by visualization of anatomical structures.
authors.affiliation: Charité, Universitätsmedizin Berlin, Campus Virchow-Klinikum, Klinik für Strahlenheilkunde, Berlin. lemke@charite.de
authors.forename: A-J
authors.initials: AJ
authors.lastname: Lemke
authors.forename: A M
authors.initials: AM
authors.lastname: Schurig-Urbaniak
authors.forename: T
authors.initials: T
authors.lastname: Liebig
authors.forename: S M
authors.initials: SM
authors.lastname: Niehues
authors.forename: H
authors.initials: H
authors.lastname: Haberl
authors.forename: T-N
authors.initials: TN
authors.lastname: Lehmann
authors.forename: R
authors.initials: R
authors.lastname: Felix
mesh_terms: D001927:Brain Diseases / Q000473:pathology* / Q000601:surgery*; D002552:Cerebral Ventricles / Q000473:pathology* / Q000601:surgery*; D004724:Endoscopy / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D012016:Reference Values; D014584:User-Computer Interface