Volume concentration and size dependence of diffuse reflectance in a fractal soft tissue model

Employing a fractal model for the particle size distribution, we examine the possibility of relating the size/volume concentration changes in the tissue to its diffuse reflectance. It is noted that for the practically interesting range of fractal dimension values alpha, the curves depicting the variation of diffuse reflectance (the ratio of diffuse reflectance at two suitably chosen source detector separations) with alpha at fixed volume concentration Tv, are single valued. The same is true if alpha is fixed and Tv is varied. This crucial observation shows that it should be possible to identify changes in the size/volume concentration of the tissue from the diffuse reflectance measurement at two source detector separations when either alpha or Tv is a priori known. Similar results have been obtained for ratio of fluence measured at two suitably chosen depths within the tissue.