Neurosurgical guidance with diffuse reflectance spectroscopy

Diffuse reflectance spectroscopy (or DRS) is a technique where the absorption and scattering characteristics of a given material are inferred from the reflectes spectra, typically in the visible and near-infrared regions. It has been used to study biological tissue in a wide range of studies from cancer detection to neurovasculature dynamics. Its simplicity and good potential to identify tissue in the brain has brought us to use it for neurosurgical guidance. We show that DRS can give blood content information due to the strong absorbers in blood deoxygenated and oxygenated hemoglobin, but most importantly, thanks to the difference in myelinated and unmyelinated axons scattering properties, it can distinguish between white and grey matter content in live tissue. We demonstrate its use in fixed and live tissues and how we plan on using the information for surgical guidance during deep brain stimulation surgery.