title: Use of anatomic or invasive markers in association with skin surface registration in image-guided surgery of the temporal bone.
abstract: CONCLUSIONS
  The use of an invasive marker in the ipsilateral temporal bone with mid-facial skin contouring for registration improved the position accuracy (PA) to levels required for otological and neuro-otological procedures.
  
  
  OBJECTIVE
  The aim of this study was to compare the PA after skin contouring with the combination of anatomic landmarks or a local invasive marker and skin surface registration for intratemporal computer-assisted navigation.
  
  
  METHODS
  Thirty-three patients undergoing a lateral skull base procedure with the Digipointeur system (Collin, Bagneux, France) based on CT scan were included in this study. Registration was obtained by a mid-facial skin contouring. In the first protocol (n=8), PA was evaluated and the position corrected for three intratemporal landmarks before evaluation of the target (round window). In a second protocol (n=25), a titanium screw was placed in the ipsilateral mastoid region before imaging. PA was measured before and after screw registration for five intratemporal landmarks.
  
  
  RESULTS
  In the first protocol, PA did not improve after the registration of the landmarks, and PA of the target was evaluated as 4.9+/-0.64 mm. In the second protocol, PA was reduced after screw registration for all landmarks with a mean PA ranging from 0 to 2.3 mm.
authors.affiliation: Otolaryngology Department, AP-HP, Beaujon Hospital, Clichy, France. alexis.bozorg-grayeli@bjn.aphp.fr
authors.forename: Alexis Bozorg
authors.initials: AB
authors.lastname: Grayeli
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Esquia-Medina
authors.forename: Yann
authors.initials: Y
authors.lastname: Nguyen
authors.forename: Stéphane
authors.initials: S
authors.lastname: Mazalaigue
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Vellin
authors.forename: Bertrand
authors.initials: B
authors.lastname: Lombard
authors.forename: Michel
authors.initials: M
authors.lastname: Kalamarides
authors.forename: Evelyne
authors.initials: E
authors.lastname: Ferrary
authors.forename: Olivier
authors.initials: O
authors.lastname: Sterkers
mesh_terms: D000328:Adult; D001863:Bone Screws; D019929:Cochlear Implantation; D006801:Humans; D011446:Prospective Studies; D025321:Surgery, Computer-Assisted / Q000592:standards*; D013701:Temporal Bone / Q000000981:diagnostic imaging / Q000601:surgery*; D014025:Titanium; D014057:Tomography, X-Ray Computed
chemical_list: D014025:Titanium