Probing nanoscale tissue structure using light scattering

Light scattering by a tissue encodes the size distribution and granularity of the scattering structures in the tissue. (1) Goniometry shows how the angle of photon deflection depends on the structure size. (2) Diffuse light measurements shows that the wavelength dependence of the reduced scattering coefficient governing diffuse light propagation is dependent on the size distribution of scatterers in a tissue. (3) Confocal reflectance is sensitive to the anisotropy of light scattering, which depends on the size distribution of scatterers. (4) Narrowangle planar backscatter of collimated incident white light from a tissue yields a spectrum that encodes the spatial frequency of refractive index fluctuations in the tissue, i.e., the granularity of the tissue. Light scattering is a useful tool for characterizing the nanoscale structure of tissues.