Submicron scale tissue multifractal anisotropy in polarized light scattering

TL;DR

This paper introduces a novel optical method to quantify submicron-scale tissue anisotropy using polarized light scattering and multifractal analysis, revealing potential biomarkers for early cancer detection.

Contribution

It develops an inverse analysis technique based on Mueller matrix Fourier analysis to measure multifractal anisotropy in biological tissues.

Findings

Demonstrates multifractal anisotropy in biological tissues.

Identifies spectral diattenuation as a signature of anisotropy.

Proposes biomarkers for early precancer detection.

Abstract

A number of disordered systems exhibit local anisotropy in the fractal or multifractal correlation and in the resulting scaling behavior, which contain wealth of information on the system. Here, we demonstrate that the spatial dielectric fluctuations in a random medium like biological tissue exhibit such multifractal anisotropy, leaving its unique signature in the wavelength variation of the light scattering Mueller matrix and manifesting as an intriguing spectral diattenuation effect. We have thus developed an inverse analysis method for the quantification of the multifractal anisotropy from the scattering Mueller matrix. The method is based on processing the relevant Mueller matrix elements in Fourier domain using Born approximation followed by multifractal analysis. Application of this technique on tissues of human cervix ex vivo demonstrate the potential of the multifractal anisotropy parameters as novel biomarkers for screening subtle micro-structural changes associated with precancers. Sensing structural anisotropy in the sub-micron length scale via the multifractal anisotropy parameters may prove valuable for non-invasive characterization of a wide class of complex materials and disordered scattering media.