title: Comparison of optical and electromagnetic tracking for navigated lateral skull base surgery.
abstract: BACKGROUND
  Navigation with optical tracking sometimes makes it difficult to establish a line-of-sight in cluttered operating theatres. On the other hand, the accuracy of electromagnetic tracking is influenced by ferromagnetic surgical equipment. We compared electromagnetic with optical tracking under controlled conditions for the lateral skull base.
  
  
  METHODS
  Six anatomical specimens were dissected to measure the target registration error (TRE) in and around the petrous bone in a wet laboratory to simulate an intraoperative setting. Specimens were registered with passive optical and electromagnetic tracking.
  
  
  RESULTS
  Overall accuracy was better using optical tracking than electromagnetic tracking (0.22 mm; 0.07-0.48 vs 0.99 mm; 0.56-1.27 mm; median, lower and upper quartiles, respectively; p < 0.001).
  
  
  CONCLUSIONS
  The accuracy of optical tracking was near the resolution of the camera system, whereas the accuracy of electromagnetic tracking was lower. Only optical tracking allows for an application accuracy of considerably less than 1 mm in high-resolution datasets.
authors: Department of Otorhinolaryngology, Medical University Innsbruck, Austria. florian.kral@i-med.ac.at
authors: Florian
authors: F
authors: Kral
authors: Elisabeth J
authors: EJ
authors: Puschban
authors: Herbert
authors: H
authors: Riechelmann
authors: Wolfgang
authors: W
authors: Freysinger
mesh_terms: D002102:Cadaver; D006801:Humans; D008280:Magnetics / Q000379:methods*; D010027:Osteotomy / Q000379:methods*; D010579:Petrous Bone / Q000601:surgery*; D010781:Photography / Q000379:methods*; D015203:Reproducibility of Results; D012371:Robotics / Q000379:methods*; D012680:Sensitivity and Specificity; D019291:Skull Base / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*