Simultaneous recovery of a full set of optical properties in turbid media using incomplete P5 approximation to CW radiance

Opt Lett. 2018 Sep 1;43(17):4188-4191. doi: 10.1364/OL.43.004188.

Abstract

Traditional methods for determining the optical properties of turbid media are implemented in diffusive regimes, where the scattering coefficient μs and anisotropy factor g are inseparable due to the similarity relation for anisotropy scattering. Determining μs and g in addition to the absorption coefficient μa normally requires measurements using thin samples or media of low scattering, which are inappropriate for in vivo applications. In this work, we propose an analytical method to simultaneously recover μa, μs, and g based on the incomplete P5 approximation (P5in) to the continuous wave (CW) radiative transport equation. The proposed method was verified using both simulated and experimental data with the relative errors less than 6.6%, 11.6%, and 8.2% for μa ranging 0.0071-0.0168 mm-1, μs ranging 2.35-8.47 mm-1, and g ranging 0.61-0.81, respectively. Since the P5in-based radiance method can be easily implemented with several measurements, it is expected to be used for recovering a full set of the optical properties in vivo.