Poster Presentation 2014 International Biophysics Congress

Characterizing the anisotropic micro structure of living biological samples using polarized photon scattering (#420)

Hui Ma 1
  1. Tsinghua University, Shenzhen, China

Polarization sensitive measurements allow one to obtain information on the micro- and macro- structure and optical properties of complex anisotropic turbid media, such as cells and biological tissues. There have been numerous attempts to apply various polarization techniques for biological and medical applications as well as material characterization. A 4x4 polarization transformation matrix, Mueller matrix, provides a comprehensive way to characterize the polarization properties of a turbid media. However, it has been known that there are many other polarization imaging techniques whose parameters can be expressed as functions of the Mueller matrix elements.
In recent studies, we have developed a comprehensive scattering model which approximates a complex anisotropic scattering medium to a mixture of spherical and cylindrical scatterers imbedded in an anisotropic ambient medium. Monte Carlo simulation programs are also developed to allow detailed examination on the relationship between the micro structure of the model represented by the parameters of the spheres, cylinders and the ambient medium, and the characteristic features of the Mueller matrix or other polarization parameters. In the mean time, we carried out experiments to take the Mueller matrix images of various types of biological samples, including living cells and cancerous tissues. Comparisons between the experimental results and the Monte Carlo simulations help us to understand the contrast mechanism of different polarization measurements and to identify new polarization parameters sensitive to specific micro structure.