Abstract
Purpose: :
To develop a human phantom for system accuracy testing of a tracked orbital endoscope.
Methods: :
An image-guided intervention software system was developed. A replica of the human skull with a globe and optic nerve within the orbit was created. An endoscope was fitted with a small position and orientation sensor at the tip. An electromagnetic field generator was placed in proximity to the orbital phantom. Preprocedural computed tomographic (CT) images of the phantom were loaded into custom-developed tracking, registration, navigation and rendering software. The orbital endoscope was then used to reach the optic nerve with guidance from the previously acquired CT scan. External fiducials were used for registration in the phantom, and registration error and tracking error were estimated.
Results: :
The CT scan position of the optic nerve within the phantom was accurately determined during the surgical procedure with manageable error. Preprocedural CT depicted the anatomy in the region of the optic nerve with real-time position updating and minimal registration error and tracking error (<5 mm).
Conclusions: :
Previously acquired CT data can be accurately co-displayed during orbital endoscopic procedures with reconstructed imaging based on the position and orientation of the endoscope.
Keywords: orbit • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • neuro-ophthalmology: optic nerve