General model for depth‐resolved estimation of the optical attenuation coefficients in optical coherence tomography

• Published in: Journal of biophotonics 2019-10, Vol.12 (10), p.e201800402-n/a
• Main Authors: Amaral, Marcello M., Zezell, Denise M., Monte, Adamo F. G., Cara, Ana C. B., Araújo, Jeann C. R., Antunes, Andrea, Freitas, Anderson Z.
• Format: Article
• Language: English
• Subjects: Attenuation coefficients; backscattering; Computer simulation; Image contrast; inverse problem; Medical imaging; optical attenuation coefficient; Optical Coherence Tomography; Optical properties; Timber industry; Tissues; Tomography; Transmittance
• ISSN: 1864-063X; 1864-0648
• DOI: 10.1002/jbio.201800402

We present the proof of concept of a general model that uses the tissue sample transmittance as input to estimate the depth‐resolved attenuation coefficient of tissue samples using optical coherence tomography (OCT). This method allows us to obtain an image of tissue optical properties instead of intensity contrast, guiding diagnosis and tissues differentiation, extending its application from thick to thin samples. The performance of our method was simulated and tested with the assistance of a home built single‐layered and multilayered phantoms (~100 μm each layer) with known attenuation coefficient on the range of 0.9 to 2.32 mm−1. It is shown that the estimated depth‐resolved attenuation coefficient recovers the reference values, measured by using an integrating sphere followed by the inverse adding doubling processing technique. That was corroborated for all situations when the correct transmittance value is used with an average difference of 7%. Finally, we applied the proposed method to estimate the depth‐resolved attenuation coefficient for a thin biological sample, demonstrating the ability of our method on real OCT images. A proof of concept of a general model using the sample transmittance as input in order to estimate the depth‐resolved attenuation coefficient for a general range of sample features using optical coherence tomography image. Simulation and phantom experiment are presented to validate our method. The retrieved estimation values of the attenuation coefficient are compatible with the reference values.