title: Remote-rendered 3D CT angiography (3DCTA) as an intraoperative aid in cerebrovascular neurosurgery.
abstract: OBJECTIVE
  To assess the viability and utility of network-based rendering in the treatment of patients with cerebral aneurysms, we implemented an intraoperative rendering system and protocol using both three-dimensional CT angiography (3DCTA) and perspective volume rendering (PVR).
  
  
  METHODS
  A Silicon Graphics InfiniteReality engine was connected via a Fast Ethernet network to a workstation in the neurosurgical operating room. A protocol was developed to isolate bone and vessels using an appropriate transfer function. Three-dimensional CT angiogram images were volume rendered and transmitted to the workstation using a bandwidth-conserving remote rendering system, and were rotated, cut using clipping planes, and viewed using normal and perspective views. Twelve patients with intracranial aneurysms were examined at surgery using this system.
  
  
  RESULTS
  Rendering performance at optimal operating bandwidths (50-60 Mb/s) was excellent, with regeneration of a high-resolution image in less than 1 s. Network performance varied in two cases, slowing image regeneration. Surgeons found the images to be useful as an adjunct to conventional imaging in understanding the morphology of complex aneurysms and their relationship to the skull base.
  
  
  CONCLUSIONS
  Intraoperative volume rendering using 3DCTA is achievable over a network, can reduce hardware costs by amortizing hardware among multiple users, and provides useful imaging information during the surgical treatment of cerebral aneurysms. Future operating suites may incorporate network-transmitted three-dimensional images as additional sources of imaging information.
authors.affiliation: Image Guidance Laboratory, Department of Neurosurgery, Stanford University School of Medicine, Stanford, California 94305-5327, USA. epw@stanford.edu
authors.forename: E P
authors.initials: EP
authors.lastname: Wilkinson
authors.forename: R
authors.initials: R
authors.lastname: Shahidi
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.forename: D P
authors.initials: DP
authors.lastname: Martin
authors.forename: J R
authors.initials: JR
authors.lastname: Adler
authors.forename: G K
authors.initials: GK
authors.lastname: Steinberg
mesh_terms: D000368:Aged; D002533:Cerebral Angiography / Q000379:methods*; D002941:Circle of Willis / Q000000981:diagnostic imaging; D003196:Computer Graphics; D003199:Computer Systems / Q000191:economics; D003365:Costs and Cost Analysis; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000601:surgery*; D007430:Intraoperative Care; D008122:Local Area Networks / Q000191:economics; D008297:Male; D008875:Middle Aged; D009873:Operating Rooms; D015641:Radiography, Interventional; D019291:Skull Base / Q000000981:diagnostic imaging; D019112:Teleradiology / Q000191:economics; D014057:Tomography, X-Ray Computed / Q000379:methods*