A whole-body registration-free navigation system for image-guided surgery and interventional radiology

RATIONALE AND OBJECTIVES. TO develop and test an image-guided navigation sy stem in which the base of reference is taken from the imaging modality, her e, a helical CT scanner. METHODS. An optical digitizer together with a calibration device is used to measure the transformation matrix between the digitizer reference system a nd a CT reference system, During intervention, it tracks radiological and s urgical tools with tool references, A specific software visually integrates the current tool position with the corresponding image information, In vit ro accuracy tests were performed. RESULTS. With helical CT, freehand positioning accuracy was 1.9 +/- 1.1 mm (mean +/- SD) in vitro (n = 718), CONCLUSIONS. The navigation system developed by the authors appears to be f easible for radiological interventions as web as for minimally invasive sur gery. It is not Limited to a certain procedure, can be used in every region of the body, and is functional after imaging, Intraprocedural scans can be integrated immediately.