Depth-dependent attenuation and backscattering characterization of optical coherence tomography by stationary...

Area of Science:

• Biomedical Optics
• Medical Imaging
• Tissue Optics

Background:

• Optical Coherence Tomography (OCT) is crucial for extracting tissue optical properties, such as attenuation coefficient and backscattering fraction, for diagnostic applications.
• Existing models for attenuation estimation often assume uniform backscattering fractions, which is inaccurate for real biological tissues.

Purpose of the Study:

• To develop a robust model for simultaneously calculating depth-wise attenuation and backscattering fractions from OCT signals.
• To create an OCT image attenuation compensation model using derived optical properties to enhance tissue visualization.

Main Methods:

• Utilized a stationary iteration method with constraint conditions to derive solutions for attenuation and backscattering fractions.
• Incorporated large variations in backscattering fraction to rectify estimations while ignoring minor ones.
• Developed an attenuation compensation model based on calculated structural information to improve OCT intensity profiles.

Main Results:

• Achieved robust and precise estimation of attenuation and backscattering fractions in simulations, phantom experiments, and ex vivo tissues.
• Demonstrated that the compensation model significantly improved OCT image resolution across the entire imaging depth.
• Validated the method's accuracy and precision using OCT A-line simulations, Monte Carlo modeling, and experimental data.

Conclusions:

• The proposed method corrects estimation bias caused by backscattering variations, enabling simultaneous, depth-resolved measurement of optical properties.
• This approach does not require prior morphological information and accurately models real-life tissues.
• The method holds significant potential for improving OCT-based disease diagnosis in complex biological tissues.