Dependence of time and space resolved reflectance on the particles size distribution near the tissue surface

The authors have performed experiments to explore the time and space resolved reflectance obtained from aqueous solutions of calibrated latex microspheres very close to the illumination point. The experimental set-up consists of a titanium-sapphire pulsed laser and a streak camera. The size distribution of the latex spheres was varied in order to obtain: (1) various anisotropy factors g with a Mie phase function, (2) various phase functions at a given g. The experimental results at early times and close to the light source have been compared to Monte-Carlo numerical simulations. The authors have deduced some rules to obtain the g value of turbid media by analyzing the backscattered light and they have demonstrated that time and space resolved reflectance could be dependent on the shape of the phase function.