Spectroscopic thermo-elastic optical coherence tomography for tissue characterization

Area of Science:

• Biomedical Optics
• Medical Imaging
• Spectroscopy

Background:

• Label-free optical imaging provides structural and biochemical information.
• Existing techniques often require multimodal integration for enhanced contrast.
• Thermo-elastic Optical Coherence Tomography (TE-OCT) offers dual contrast: optical reflectance and thermo-elastic deformation.

Purpose of the Study:

• To demonstrate spectroscopic TE-OCT as a tool for tissue identification.
• To characterize the relationship between thermo-elastic displacement and optical properties.
• To extract and analyze thermo-elastic spectra for identifying specific tissue components.

Main Methods:

• Utilized short laser pulses to induce thermo-elastic tissue deformation.
• Employed phase-sensitive OCT to measure surface displacement.
• Validated experimental results with a 2D analytical model.
• Extracted thermo-elastic spectra from phantoms and coronary artery tissues.

Main Results:

• Established a correlation between thermo-elastic displacement and optical absorption, excitation, fluence, and illumination area.
• Successfully extracted thermo-elastic spectra of elastic phantoms and coronary artery tissue components.
• Identified specific tissue components, notably lipids, through their unique spectral response.
• Demonstrated the capability of spectroscopic TE-OCT to identify lipid biomarkers in atherosclerotic lesions.

Conclusions:

• Spectroscopic TE-OCT is a promising label-free, dual-contrast, all-optical imaging technique.
• The method enables identification of specific tissue components based on thermo-elastic spectral signatures.
• TE-OCT holds potential for advancing biomedical research and clinical pathology diagnosis, particularly for atherosclerotic disease.