Registration accuracy and practicability of laser-directed surface matching

✍ Scribed by J. Schlaier; J. Warnat; A. Brawanski

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 352 KB
• Volume: 7
• Category: Article
• ISSN: 1092-9088
• DOI: 10.1002/igs.10053

✦ Synopsis

The aim of our study was to evaluate the registration accuracy and practicability of a new laser registration technique in comparison to marker registration. From January to August 2001, 36 patients (23 male, 13 female) with brain lesions were operated with navigational guidance. Thirty-five patients were registered by paired-point registration. In 16 patients, a second registration was carried out using a special laser pointer for surface matching (z-touch™, BrainLab, Heimstetten, Germany). Accuracy was evaluated by touching seven anatomic landmarks and a target fiducial with the nonsterile pointer. The distance from the virtual pointer tip to these points was determined on the monitor display (600% zoom). Laser registration is fully retrospective and allows registrations when no markers are applied. z-touch™ registration is more sophisticated and time-consuming than marker-based registration (registration time for z-touch™ ‫؍‬ 7.4 ؎ 3.7 min; for markers ‫؍‬ 4.1 ؎ 1.7 min; p < 0.005). Marker registration proved to be more accurate than z-touch™ registration with regard to localization of anatomical landmarks and target fiducials (precision with z-touch™ ‫؍‬ 2.77 ؎ 1.64 mm; with markers ‫؍‬ 1.31 ؎ 0.87 mm; p < 0.01). Although the registration error was increased and preparation time prolonged with the z-touch™ technique, it proved to be a valuable option, especially in children.