Probe versus microscope: a comparison of different methods for image-to-patient registration

Area of Science:

• Medical technology
• Surgical navigation
• Otolaryngology

Background:

• Computer-aided navigation is integral to ENT surgery, relying heavily on accurate pre-operative registration.
• The accuracy of navigation systems is determined by the registration process, with Target Registration Error (TRE) being a critical metric.
• Both microscopes and probes can be used for registration and navigation, but their comparative performance requires evaluation.

Purpose of the Study:

• To compare the performance of microscope-based versus probe-based registration methods in computer-aided ENT surgery.
• To evaluate the impact of different registration techniques on the accuracy of surgical navigation.
• To determine the most effective approach for achieving lower Target Registration Errors (TREs).

Main Methods:

• Optical tracking was employed to register a plastic skull to CT images using paired-point registration.
• Four distinct registration methods were assessed using both a microscope and a probe, measuring TREs at 10 target points.
• The influence of additional surface registration and external fiducials on accuracy was investigated.

Main Results:

• Probe registration yielded a significantly smaller TRE compared to microscope registration.
• The addition of surface registration or external fiducials did not enhance navigation accuracy for either the microscope or the probe.
• The lowest mean TRE was achieved using only paired-point registration with radiolucent markers.

Conclusions:

• Probe-based registration and navigation demonstrate superior accuracy, achieving lower TREs than microscope-based methods in ENT surgery simulations.
• Neither additional surface registration nor external fiducials are necessary to improve the accuracy of navigated ENT surgery.
• Paired-point registration with radiolucent markers provides optimal accuracy for navigated ENT procedures.