Intact primate brain tissue identification using a completely fibered coherent Raman spectroscopy system

Area of Science:

• Biomedical Optics
• Neuroscience
• Spectroscopy

Background:

• Coherent Raman spectroscopy offers label-free sensing but requires bulky lasers, hindering clinical translation.
• Existing fiber probes face challenges with silica propagation and precise targeting for neurosurgery.

Purpose of the Study:

• To develop a compact, all-fiber coherent anti-Stokes Raman scattering (CARS) system for clinical neurosurgical applications.
• To enable high-resolution, label-free imaging and guidance during electrode implantation procedures.

Main Methods:

• Created an all-fiber CARS system using rapidly tunable, turn-key fiber-lasers with long pulse-widths (25 ps) for silica compatibility.
• Designed a probe with a $$ outer diameter, fitting within commercial stylets for deep brain stimulation (DBS) electrodes.
• Acquired high-wavenumber CARS spectra within tens of milliseconds.

Main Results:

• Successfully identified brain tissue types in intact nonhuman primate brains.
• Demonstrated high-resolution delineation of white and gray matter.
• Achieved orders-of-magnitude improvement in spatial resolution compared to spontaneous Raman.

Conclusions:

• The developed all-fiber CARS system is suitable for clinical neurosurgical guidance and diseased tissue detection.
• The system offers superior spatial resolution and potential for 3-D imaging, overcoming limitations of previous methods.
• This technology shows promise for enhancing the precision and safety of neurosurgical interventions.