Lens-free common path OCT probe for quantification of optical scattering properties (Conference Presentation)

Tissue optical properties have become an increasingly promising avenue of diagnosis and screening for cancers and may provide contrast for real time monitoring of tumor ablation therapy. Of particular interest, are methods that can quantify scattering properties while providing spatial context or a map of the tissue being measured. Optical Coherence Tomography (OCT) is a non-destructive imaging modality with high 3D resolution which can be miniaturized into a probe compatible with common endoscopes. OCT has recently been used to quantify optical scattering properties, and endoscopic access to luminal organs allows examination of the thin epithelial layer, wherein many cancers originate. We present a fiber probe capable of quantifying optical properties with no distal optics providing low-cost disposable functionality. A reflection from the distal fiber face provides a common path reference through the fiber and eliminates the need for reference arm with dispersion compensation. A custom visible light OCT instrument was adapted to the self-reference fiber capable of a-scan imaging hundreds of microns into porcine esophagus tissue. B-scan images are produced by dragging the fiber along the tissue surface. Tissue was thermally ablated to create controllable scattering contrast with normal tissue. Image analysis with a custom MATLAB algorithm demonstrated significant increases in scattering coefficients which has been observed previously in a benchtop scanning OCT system. Visible light maximizes scatter contrast making Vis-OCT an ideal tool for cancer screening. Additionally, the lack of a distal optics and scanning mechanism offers a cost-effective, disposable functionality.