Aspects of similarity in tissue optics with strong forward scattering

The similarity studied in this paper links the diffusion exponent to the reduced albedo. If F is the ratio of the diffusion exponent assumed by standard diffusion theory to the actual value of the diffusion exponent, it is shown that for forward-scattering functions, as often found in biological tissues, the values of F approach limiting curves. These curves depend on a constant in the homologous scattering patterns, which can describe Henyey-Greenstein scattering patterns, but which can also approximate Rayleigh-Gans phase functions. Finally, a practical approach for estimating the solution for mixtures of these forward-scattering phase functions with isotropic scatterers has been given.