Fiber spectral domain optical coherence tomography for in vivo rat brain imaging

A well established navigation method is one of the key conditions for successful brain surgery: It should be accurate, safe and online operable. Recent research shows that Optical Coherence Tomography is a potential solution for this application by providing a high resolution and small probe dimension. In this study a fiber Spectral-Domain OCT system with a super luminescent diode with the center wavelength of 840 nm providing 13.6 μm axial resolution was used. A single mode fiber (Ø 125 μm) was employed as the detecting probe. The information acquired by OCT was reconstructed into grayscale images by vertically aligning several A-scans from the same trajectory with different depth, i.e. forward scanning. For scans of typical white matter, the images showed a higher reflection of light intensity with lower penetration depth as well as a steeper attenuation rate compared to the scans typical for grey matter. Since the axial resolution of this OCT system is very high, some microstructures lying on the striatum, hippocampus and thalamic nucleus were visible in these images. The research explored the potential of OCT to be integrated into a stereotactic surgical robot as a multi-modal navigation method.