Sensing an aqueous Intralipid suspension with optical coherence tomography; reconstruction of the scattering coefficients

摘要

The working principle of optical coherence tomography (OCT) makes it possible to detect backscattered photons as a function of depth. The OCT signal includes single and least-scattered photons as well as multiple-scattered photons, and provides a logarithmic depth profile of coherently backscattered light in an OCT image. Single and least-scattered photons contribute to the information part of the OCT signal, while multiple-scattered photons mainly decrease the resolution. When the OCT signal is analyzed, rapid attenuation of the signal in a scattering medium is observed. Based on an exponential decay approximation that fits the OCT profile and the results of Monte Carlo simulations, it was possible to reconstruct the scattering coefficient μ_s for some concentrations of Intralipid water suspension. The case of single scattering was considered for 0.5 %, 1 %, 1.5 % and 2 % Intralipid. The reconstruction led to results very close to the theoretical values of the μ_s. For higher concentrations (9 % and 10 %), the reconstructed values were larger than the theoretical ones.