title: X-ray and optical stereo-based 3D sensor fusion system for image-guided neurosurgery.
abstract: OBJECTIVE
  In neurosurgery, an image-guided operation is performed to confirm that the surgical instruments reach the exact lesion position. Among the multiple imaging modalities, an X-ray fluoroscope mounted on C- or O-arm is widely used for monitoring the position of surgical instruments and the target position of the patient. However, frequently used fluoroscopy can result in relatively high radiation doses, particularly for complex interventional procedures. The proposed system can reduce radiation exposure and provide the accurate three-dimensional (3D) position information of surgical instruments and the target position.
  
  
  METHODS
  X-ray and optical stereo vision systems have been proposed for the C- or O-arm. Two subsystems have same optical axis and are calibrated simultaneously. This provides easy augmentation of the camera image and the X-ray image. Further, the 3D measurement of both systems can be defined in a common coordinate space.
  
  
  RESULTS
  The proposed dual stereoscopic imaging system is designed and implemented for mounting on an O-arm. The calibration error of the 3D coordinates of the optical stereo and X-ray stereo is within 0.1 mm in terms of the mean and the standard deviation. Further, image augmentation with the camera image and the X-ray image using an artificial skull phantom is achieved.
  
  
  CONCLUSIONS
  As the developed dual stereoscopic imaging system provides 3D coordinates of the point of interest in both optical images and fluoroscopic images, it can be used by surgeons to confirm the position of surgical instruments in a 3D space with minimum radiation exposure and to verify whether the instruments reach the surgical target observed in fluoroscopic images.
authors.affiliation: School of Electrical Engineering and Computer Science, Kyungpook National University, 80 Daehakro, Bukgu, Daegu, 41566, Korea.
authors.forename: Duk Nyeon
authors.initials: DN
authors.lastname: Kim
authors.affiliation: School of Electrical Engineering and Computer Science, Kyungpook National University, 80 Daehakro, Bukgu, Daegu, 41566, Korea.
authors.forename: You Seong
authors.initials: YS
authors.lastname: Chae
authors.affiliation: School of Electrical Engineering and Computer Science, Kyungpook National University, 80 Daehakro, Bukgu, Daegu, 41566, Korea. mykim@ee.knu.ac.kr.|Research Center for Neurosurgical Robotic System, Kyungpook National University, Daegu, 41566, Korea. mykim@ee.knu.ac.kr.|Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21205, USA. mykim@ee.knu.ac.kr.
authors.forename: Min Young
authors.initials: MY
authors.lastname: Kim
mesh_terms: D002138:Calibration; D004867:Equipment Design; D005471:Fluoroscopy / Q000295:instrumentation*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D019635:Neurosurgical Procedures / Q000379:methods*; D055096:Optical Devices; D019047:Phantoms, Imaging; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*; D014965:X-Rays
keywords: Augmented reality; Navigation; Stereo images; Three-dimensional coordinates; X-ray fluoroscopy