title: Towards markerless navigation for percutaneous needle insertions.
abstract: OBJECTIVE
  Percutaneous needle insertions are increasingly used for diagnosis and treatment of abdominal lesions. The challenging part of computed tomography (CT)-guided punctures is the transfer of the insertion trajectory planned in the CT image to the patient. Conventionally, this often results in several needle repositionings and control CT scans. To address this issue, several navigation systems for percutaneous needle insertions have been presented; however, none of them has thus far become widely accepted in clinical routine. Their benefit for the patient could not exceed the additional higher costs and the increased complexity in terms of bulky tracking systems and specialized markers for registration and tracking.
  
  
  METHODS
  We present the first markerless and trackerless navigation concept for real-time patient localization and instrument guidance. It has specifically been designed to be integrated smoothly into the clinical workflow and does not require markers or an external tracking system. The main idea is the utilization of a range imaging device that allows for contactless and radiation-free acquisition of both range and color information used for patient localization and instrument guidance.
  
  
  RESULTS
  A first feasibility study in phantom and porcine models yielded a median targeting accuracy of 6.9 and 19.4 mm, respectively.
  
  
  CONCLUSIONS
  Although system performance remains to be improved for clinical use, expected advances in camera technology as well as consideration of respiratory motion and automation of the individual steps will make this approach an interesting alternative for guiding percutaneous needle insertions.
authors.affiliation: Junior Group: Computer-Assisted Interventions, German Cancer Research Center (DKFZ), Heidelberg, Germany. aseitel@ece.ubc.ca.|The Robotics and Control Laboratory, University of British Columbia, Vancouver, Canada. aseitel@ece.ubc.ca.
authors.forename: Alexander
authors.initials: A
authors.lastname: Seitel
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Clinic Heidelberg, Heidelberg, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Bellemann
authors.affiliation: Department of General, Visceral and Transplant Surgery, University Clinic Heidelberg, Heidelberg, Germany.
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Hafezi
authors.affiliation: Junior Group: Computer-Assisted Interventions, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Alfred M
authors.initials: AM
authors.lastname: Franz
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Clinic Heidelberg, Heidelberg, Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: Servatius
authors.affiliation: Department of General, Visceral and Transplant Surgery, University Clinic Heidelberg, Heidelberg, Germany.
authors.forename: Arash
authors.initials: A
authors.lastname: Saffari
authors.affiliation: Junior Group: Computer-Assisted Interventions, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kilgus
authors.affiliation: Division of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Heinz-Peter
authors.initials: HP
authors.lastname: Schlemmer
authors.affiliation: Department of General, Visceral and Transplant Surgery, University Clinic Heidelberg, Heidelberg, Germany.
authors.forename: Arianeb
authors.initials: A
authors.lastname: Mehrabi
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Clinic Heidelberg, Heidelberg, Germany.
authors.forename: Boris A
authors.initials: BA
authors.lastname: Radeleff
authors.affiliation: Junior Group: Computer-Assisted Interventions, German Cancer Research Center (DKFZ), Heidelberg, Germany. l.maier-hein@dkfz.de.
authors.forename: Lena
authors.initials: L
authors.lastname: Maier-Hein
mesh_terms: D006801:Humans; D009339:Needles; D019047:Phantoms, Imaging; D011677:Punctures / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D057188:Workflow
keywords: Computer-assisted intervention; Needle insertion; Range imaging; Surface registration; Time of flight