Evaluating an Image-Guided Operating Room with Cone Beam CT for Skull Base Surgery

Area of Science:

• Neurosurgery and Otolaryngology
• Medical Imaging Technology
• Surgical Navigation Systems

Background:

• Skull base surgery demands precise preoperative planning and intraoperative guidance.
• Current surgical navigation often relies solely on preoperative scans, limiting real-time assessment.
• Intraoperative imaging modalities are crucial for enhancing surgical accuracy and patient safety.

Purpose of the Study:

• To evaluate the image quality of intraoperative cone-beam computed tomography (CBCT) for anatomical landmarks in sinus and skull base surgery.
• To determine the registration error of a surgical navigation system utilizing intraoperative CBCT.
• To assess the impact of intravenous contrast on image quality and vascular visualization.

Main Methods:

• Retrospective analysis of 46 intraoperative CBCT scans from 34 patients undergoing skull base or head and neck procedures.
• Evaluation of 30 anatomical landmarks for bony detail, soft-tissue visualization, vascular visualization, and artifact presence.
• Measurement of Hounsfield units (HU) for contrast enhancement and calculation of fiducial registration error (FRE) for navigation accuracy.

Main Results:

• CBCT provided high-quality bony detail (median score 5) and acceptable soft-tissue visualization (median score 2).
• Intravenous contrast significantly improved vascular visualization (median score 3 postcontrast vs. 1 precontrast) and carotid artery enhancement (334 HU).
• The mean fiducial registration error (FRE) was 1.8 mm, consistent with standard surgical navigation techniques.

Conclusions:

• Intraoperative CBCT delivers high-resolution bony detail crucial for assessing complex skull base resections.
• The addition of IV contrast enhances vascular visualization, aiding surgical decision-making.
• CBCT-based surgical navigation demonstrates reliable registration accuracy, supporting its use in complex head and neck procedures.