Cranial surgery with an expanded compact intraoperative magnetic resonance imager. Technical note

Area of Science:

• Neurosurgery
• Medical Imaging
• Biomedical Engineering

Background:

• Limitations of earlier intraoperative magnetic resonance (iMR) imagers necessitated development of improved systems.
• The PoleStar N20 iMR imager was designed with a stronger magnetic field (0.15 T), wider pole gap, and improved gantry for enhanced usability.

Observation:

• The study evaluated the PoleStar N20 iMR imager in 55 neurosurgical patients with various diagnoses, including glioma and meningioma.
• Additional operating room (OR) time and imaging sessions per patient were recorded.
• Stereotactic accuracy was assessed using a phantom, with T1-weighted images and thinner slices showing greater accuracy.

Findings:

• The PoleStar N20 imager required an average of 1.1 additional hours in the OR per surgery, with an average of 2.3 imaging sessions.
• Accuracy was not significantly affected by the phantom's position within the magnetic field.
• T1-weighted images and slices ≤4 mm demonstrated the highest stereotactic accuracy.

Implications:

• The PoleStar N20 enhances the practicality of low-field-strength intraoperative neuroimaging.
• Improved ergonomics and positioning decrease OR time, promoting more frequent use of iMR during surgery.
• This advancement facilitates more effective intraoperative guidance for neurosurgical procedures.