title: Distribution templates of the fiducial points in image-guided neurosurgery.
abstract: BACKGROUND
  Point-pair registration is widely used in an image-guided neurosurgery system. Poor distribution of the fiducial points leads to an increase in the target registration error (TRE).
  
  
  OBJECTIVE
  This study aimed to provide templates consisting of optimized positioning of the fiducial points to reduce the TRE in image-guided neurosurgery.
  
  
  METHODS
  We divided the head into 6 regions and provided distribution templates of the fiducial points for each of them. A variable termed TREM(r) was used to express the approximate expected square of the TRE at the target point with a specified distribution of fiducial points. We randomly selected 85 patients from 5 hospitals who underwent image-guided neurosurgery and compared the TREM(r) of the real fiducial points with that of the templates.
  
  
  RESULTS
  We grouped the patients by hospitals and regions. The mean TREM(r)s of the templates were much smaller than those of the real fiducial points. In each group, the range of the TREM(r) values of the templates was much smaller than that of the real fiducial points.
  
  
  CONCLUSIONS
  This study provides an easy method to implement a good distribution of the fiducial points to help reduce TRE in image-guided neurosurgery. The templates are simple and exact and can be easily integrated into current workflow.
authors.affiliation: Digital Medical Research Center, Shanghai Medical School, Fudan University, Shanghai, China.
authors.forename: Manning
authors.initials: M
authors.lastname: Wang
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Song
mesh_terms: D000465:Algorithms; D000886:Anthropometry / Q000295:instrumentation / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods; D008953:Models, Anatomic; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods; D038361:Neuronavigation / Q000295:instrumentation / Q000379:methods*; D019635:Neurosurgical Procedures / Q000295:instrumentation / Q000379:methods*; D056888:Patient Positioning / Q000295:instrumentation / Q000379:methods; D012015:Reference Standards; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods; D014584:User-Computer Interface