Potentials of skin diagnostic with digital photometric patterning of backscattered linearly polarized light

摘要

Potentials of two modalities of skin diagnostic with focused and expanded linearly polarized probe light are studied. For the focused beam (wavelength 650 nm) the photometric patterns of light backscattered from skin and collagenous tissue phantoms were recorded using digital camera. It is shown that equiintensity contours are well fitted with ellipses that appeared to follow the orientation of collagen fibers. In the peripheral zone from the entry point of the probe beam the ratio of the ellipses semi-axes is correlated with the ratio of reduced scattering coefficients obtained from intensity profiles. In the vicinity of the entry point it depends on the mutual orientation of polarization vector and collagen fibers. For the expanded probe beam the digital mapping of the residual polarization degree of backscattered linearly polarized light allowed visualization of the hidden structure of earlier fibrosis of the mouse skin arisen from X-ray treatment. The structure of the skin fibrosis was enhanced using Fourier transform filtering of polarization degree pattern. The pattern scanning with Pearson correlation coefficient was developed to determine the orientation and characteristic size of hidden structure. Both modalities may be potentially used for diagnostic of skin abnormalities, such as fibrosis.