Preoperative Visualization of Cranial Nerves in Skull Base Tumor Surgery Using Diffusion Tensor Imaging Technology

Area of Science:

• Neuroimaging
• Neurosurgery
• Medical Visualization

Background:

• Skull base tumors pose significant surgical challenges due to their proximity to critical cranial nerves (CNs).
• Accurate visualization of the spatial relationship between tumors and CNs is crucial for surgical planning and preserving neurological function.

Purpose of the Study:

• To visualize cranial nerves (CNs) using diffusion tensor imaging (DTI) with specialized parameters.
• To evaluate the accuracy of preoperative DTI-based estimations of nerve-tumor relationships through intraoperative confirmation.

Main Methods:

• Acquired 3T MRI scans including 3D-FSPGR, FIESTA, and DTI from 18 patients with skull base tumors.
• Integrated DTI data into 3D Slicer for fiber tracking and overlapped with anatomical images to delineate nerve courses.
• Performed 3D tumor reconstruction to assess the relationship (neighboring, encasing, invading) with nerves.

Main Results:

• Successfully traced the optic pathway (optic chiasm) in tuberculum sellae meningioma and hypophysoma cases.
• Clearly visualized the oculomotor nerve in parasellar meningioma cases and cisternal segments of trigeminal and abducens nerves in vestibular schwannomas and petroclival meningiomas.
• Demonstrated strong correlation between preoperative 3D tumor modeling/tractography and intraoperative findings regarding CN-tumor spatial relationships.

Conclusions:

• Preoperative 3D reconstruction of CNs adjacent to skull base tumors is feasible using DTI and 3D Slicer.
• DTI technology is a valuable tool for predicting the course, location, and spatial relationship (syntopy) between CNs and skull base tumors.