Imaging thermally damaged tissue by Polarization Sensitive Optical Coherence Tomography

Area of Science:

• Biomedical Optics
• Medical Imaging
• Tissue Optics

Background:

• Biological tissues possess birefringence, particularly fibrous structures like collagen.
• Thermal damage denatures collagen, reducing its birefringence.
• This change in birefringence can serve as an optical marker for thermal injury.

Purpose of the Study:

• To investigate the use of Polarization Sensitive Optical Coherence Tomography (PS-OCT) for imaging thermal damage.
• To assess the reduction of birefringence in biological tissues subjected to thermal insult.
• To demonstrate the potential of PS-OCT for burn depth assessment.

Main Methods:

• Utilized PS-OCT to simultaneously detect fringe signal amplitudes in orthogonal polarization states.
• Measured changes in polarization due to optical phase delay in birefringent media.
• Employed a Michelson interferometer setup with simultaneous detection of backscattered light and reference arm interference.

Main Results:

• Successfully imaged the reduction of birefringence in thermally damaged porcine tendon and skin.
• Observed a decrease in birefringence correlating with thermal denaturation of collagen (56-65°C).
• Demonstrated PS-OCT's capability to visualize structural changes indicative of thermal damage.

Conclusions:

• PS-OCT is a viable technique for imaging birefringence changes in biological tissues.
• The reduction in birefringence serves as a reliable optical marker for thermal damage.
• PS-OCT shows significant potential for non-invasive burn depth assessment.