title: Soft tissue scanning for patient registration in image-guided surgery.
abstract: Prior to an image-guided surgical intervention, a correlation between the patient's data set and the surgical site is required. This study introduces a markerless registration method for cranio-maxillofacial surgery that is based on a high-resolution laser scan of the patient's skin surface. The Surgical Segment Navigator SSN++ rejects contaminated surface measurements in a way similar to the bluescreen technique. Acquisition of the spatial position and the corresponding surface color of each laser-scanned point facilitates this bluescreen method, removing points with a defined surface color, e.g., blue or green points. The accuracy of the laser-scan-based registration was measured via additional intraoral titanium-markers. These markers served only to check the accuracy of the markerless registration process. In twelve patients, the stability and accuracy of the data set alignment was evaluated for high-(300,000 surface points), medium-, and low-resolution (down to 3,750 surface points) laser scanning. The accuracy of the registration technique was best for high-resolution laser scanning (mean deviation 1.1 mm; maximum deviation 1.8 mm). Low-resolution laser scans revealed inaccuracies up to 6 mm.
authors.affiliation: Department of Cranio-Maxillofacial Surgery, University of Heidelberg, Heidelberg, Germany. ruediger@marmulla.com
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Marmulla
authors.forename: Stefan
authors.initials: S
authors.lastname: Hassfeld
authors.forename: Tim
authors.initials: T
authors.lastname: Lüth
authors.forename: Ulrich
authors.initials: U
authors.lastname: Mende
authors.forename: Joachim
authors.initials: J
authors.lastname: Mühling
mesh_terms: D005145:Face / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D007834:Lasers; D012888:Skull Neoplasms / Q000601:surgery; D025321:Surgery, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000295:instrumentation