title: Navigation-based needle puncture of a cadaver using a hybrid tracking navigational system.
abstract: OBJECTIVE
  The purpose of this study was to determine the puncture accuracy of a navigational system, Medarpa, in a soft tissue environment using augmented overlay imaging.
  
  
  METHODS
  Medarpa is an optical electromagnetic tracking system, which allows tracking of instruments, the radiologist's head position, and the transparent display. The display superimposes a computed tomography scan of a cadaver chest on a human cadaver in real time. In group A, needle puncture was performed using the Medarpa system. Three targets located inside the cadaver chest were selected. In group B, the same targets were used to perform standard computed tomography-guided puncture using a single-slice technique. A total of 42 punctures were performed in each group. Postpuncture computed tomography scans were made to verify needle tip positions.
  
  
  RESULTS
  Mean deviation from targets was 8.42 mm +/- 1.78 mm for group A and 8.90 mm +/- 1.71 mm for group B. No significant difference was found between group A and B in any target (P > 0.05). No significant difference was found between the targets of the same group (P > 0.05). Procedural time for 42 punctures was 160 minutes in group A versus 289 minutes in group B (P < 0.05).
  
  
  CONCLUSIONS
  Needle puncture in a soft tissue environment using the navigational system Medarpa can be reliably performed and matches the accuracy achieved by a computed tomography-guided puncture technique.
authors.affiliation: Institute for Diagnostic and Interventional Radiology, Johann Wolfgang Goethe University, Frankfurt/Main, Germany. fawad@gmx.de
authors.forename: M Fawad
authors.initials: MF
authors.lastname: Khan
authors.forename: Selami
authors.initials: S
authors.lastname: Dogan
authors.forename: Adel
authors.initials: A
authors.lastname: Maataoui
authors.forename: Stefan
authors.initials: S
authors.lastname: Wesarg
authors.forename: Jessen
authors.initials: J
authors.lastname: Gurung
authors.forename: Hanns
authors.initials: H
authors.lastname: Ackermann
authors.forename: Mirko
authors.initials: M
authors.lastname: Schiemann
authors.forename: Gerhard
authors.initials: G
authors.lastname: Wimmer-Greinecker
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Vogl
mesh_terms: D001707:Biopsy, Needle / Q000295:instrumentation* / Q000379:methods; D002102:Cadaver; D003936:Diagnosis, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008280:Magnetics / Q000295:instrumentation*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D015203:Reproducibility of Results; D012371:Robotics / Q000295:instrumentation* / Q000379:methods; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods; D014584:User-Computer Interface