title: Surface rendering-based virtual intraventricular endoscopy: retrospective feasibility study and comparison to volume rendering-based approach.
abstract: OBJECTIVE
  Virtual endoscopic simulations using volume rendering (VR) have been proposed as a tool for training and understanding intraventricular anatomy. It is not known whether surface rendering (SR), an alternative to VR, can visualize intraventricular and subependymal structures better and thus making the virtual endoscope more useful for simulating the intraventricular endoscopy. We sought to develop SR-virtual endoscopy and compared the visibility of anatomical structures in SR and VR using retrospective cases.
  
  
  METHODS
  Fourteen patients who underwent endoscopic intraventricular surgery of third ventricle enrolled the study. SR-virtual endoscopy module was developed in open-source software 3D Slicer and virtual endoscopic scenes from the retrospective cases were created. VR virtual endoscopy of the same cases was prepared in commercial software. Three neurosurgeons scored the visibility of substructures in lateral and third ventricle, arteries, cranial nerves, and other lesions Results: We found that VR and SR-virtual endoscopy performed similarly in visualization of substructures in lateral and third ventricle (not significant statistically). However, the SR was statistically significantly better in visualizing subependymal arteries, cranial nerves, and other lesions (p<0.05, respectively).
  
  
  CONCLUSIONS
  We concluded that SR-virtual endoscopy is a promising tool to visualize critical anatomical structures in simulated endoscopic intraventricular surgery. The results lead us to propose a hybrid technique of volume and surface rendering to balance the strength of surface rendering alone in visualizing arteries, nerves and lesions, with fast volume rendering of third and lateral ventricles.
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Boston, MA, USA. nnakajima@bwh.harvard.edu
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Nakajima
authors.forename: Jun
authors.initials: J
authors.lastname: Wada
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Miki
authors.forename: Jo
authors.initials: J
authors.lastname: Haraoka
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Hata
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000473:pathology; D002536:Cerebral Arteries / Q000473:pathology; D002552:Cerebral Ventricles / Q000033:anatomy & histology*; D002648:Child; D002675:Child, Preschool; D003198:Computer Simulation; D003391:Cranial Nerves / Q000473:pathology; D004724:Endoscopy / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D012189:Retrospective Studies; D012984:Software; D020542:Third Ventricle / Q000601:surgery