Practical aspects for optimal registration (matching) on the lateral skull base with an optical frameless...

Area of Science:

• Neurosurgery
• Medical Imaging
• Surgical Navigation

Background:

• Lateral skull base surgery traditionally uses pointer systems or microscopes.
• An optical pointer system utilizing anatomic landmarks and surface points has been developed.
• This system aims to improve precision in computer-aided surgery.

Purpose of the Study:

• To evaluate the accuracy of paired-point matching and surface matching techniques.
• To assess the performance of an optical computer-aided surgery system for lateral skull base procedures.
• To identify optimal matching strategies for enhanced surgical navigation.

Main Methods:

• Computed tomography (CT) of a cadaver skull was performed and processed on a workstation.
• An infrared camera system with a reference base and needle pointer was employed.
• Accuracy was assessed by comparing determined anatomic landmarks and surface points with actual markers, calculating target error.

Main Results:

• Paired-point matching alone achieved a mean average error of 0.79 mm in the best series.
• Surface simulation showed a decrease in accuracy with paired-point matching alone.
• Surface matching demonstrated an improvement in accuracy under skin simulation conditions.

Conclusions:

• Five specific anatomic points are recommended for lateral skull base matching: tip of the mastoid, mastoid foramen, umbo, frontozygomatic suture, and anterior nasal spine.
• Surface matching is advised for achieving greater accuracy in clinical applications.
• The study supports the utility of optical computer-aided surgery systems for lateral skull base procedures.