Current spine procedures can suffer from a variety of complications resulting in a high incidence (up to 55%) of misplaced screws and implants. This can lead to devastating clinical consequences, including neurologic and vascular injury, and extensive physical, mental, and economic damage. Surgical navigation has a great potential to reduce these risks through accurate guidance; however present technologies rely on intraoperative imaging that uses ionizing radiation (e.g. computed tomography, or fluoroscopy), which limits surgical anatomy registration updates to less than 3-4 time points during surgery. They also require cumbersome and lengthy set-up and registration of fiducial markers and have limited abilities to account for motion that occurs during surgery and patient positioning. Therefore, the investigators propose a real-time intraoperative optical topographical imaging based surgical guidance system capable of accurately guiding the placement of implanted devices such as screws.

The hypothesis is that optical visualization of surgically exposed anatomy with the Biophotonics and Bioengineering Laboratory (BBL) surgical navigation prototype, when registered with pre-operative imaging (CT or MRI), can accurately estimate subsurface anatomy and allow tracking the position of surgical instruments in real-time, using an intraoperative non-contact optical imaging system during spinal surgical procedures. This is based on the completed preliminary study of 40 spinal procedures. The specific research aim is as follows: Validate the ability of the BBL surgical navigation prototype to function as the sole navigation system during spinal surgical procedures. The study will focus on testing the robustness of the system to appropriately function on a variety of spinal surgeries.

Inclusion Criteria:

• Greater than 18 years of age, able to provide consent, or has substitute decision maker available to consent.
• Scheduled to undergo spinal instrumentation surgery involving pedicle or lateral mass screw insertion or brain tumor resection or biopsy.
• Scheduled for pre-operative CT/ MRI scan.
• No contra-indication for a post-operative CT/MRI scan.

Exclusion Criteria:

• Previous spinal decompression with significant laminectomy performed at the level intended for instrumentation
• Previous spinal decompression with laminoplasty performed at the level intended for instrumentation