Chemically-selective imaging of brain structures with CARS microscopy

Area of Science:

• Neuroscience
• Biomedical Optics
• Chemical Imaging

Background:

• Current clinical brain imaging (CT, MRI, PET) has limitations in definitively distinguishing neoplastic from benign pathologies pre-operatively.
• Brain biopsy is often required for definitive diagnosis, posing risks to patients.
• Coherent anti-Stokes Raman scattering (CARS) microscopy is a nonlinear, vibrationally-sensitive technique enabling chemically-selective imaging.

Purpose of the Study:

• To demonstrate the utility of CARS microscopy for imaging brain structure and pathology ex vivo.
• To explore CARS microscopy as a tool for intraoperative optical diagnosis of brain lesions.
• To assess the feasibility of in vivo CARS vibrational histology for neuropathological diagnosis.

Main Methods:

• Utilized CARS microscopy, a nonlinear optical technique, for imaging fresh, unfixed, and unstained ex vivo brain tissue.
• Applied CARS microscopy to identify normal brain structures and primary glioma.
• Explored the potential for sub-cellular spatial resolution and near real-time temporal resolution in brain tissue imaging.

Main Results:

• Demonstrated CARS microscopy's capability for high-sensitivity, chemically-selective, three-dimensional imaging without exogenous labeling agents.
• Showcased CARS's ability to provide diverse tissue contrasts, similar to MRI but with superior spatial and temporal resolution.
• Successfully identified normal brain structures and primary glioma in ex vivo samples using CARS vibrational histology.

Conclusions:

• CARS microscopy is a feasible clinical tool for neuropathological diagnosis, offering molecular specificity and high resolution.
• The technique can augment diagnostic accuracy in needle biopsies and define tumor margins during surgery.
• CARS imaging holds significant potential for improving neurosurgical patient care through faster, more definitive intraoperative diagnoses.