Biological tissue-enhanced visualization through polarimetric observables

Abstract

Polarimetry comprises a set of optical techniques of great interest in biophotonics due to its capability to obtain relevant information from biological samples by means of noninvasive and nondestructive methods. For instance, they are useful in pathology detection or different biological structures classification, among others. By studying the polarimetric response of biological samples we can obtain the information of how different structures produce different changes in the polarimetric characteristics of light. These changes depend on the polarimetric properties of the samples: depolarization, dichroism or retardance. From the experimental measurement of the Mueller matrix (M) of a sample, these polarimetric observables related to the mentioned tissue properties can be obtained. In this work, we propose the study of a particular set of observables derived from the Arrow decomposition of M. These parameters are used to inspect different biological tissues properties with the purpose of obtaining images with enhanced contrast of different biological structures in a tissue. In particular, we applied these observables to the study of a sample of animal origin: an ex-vivo cow brain; in order to differenciate between white and gray matter. Obtained results provide the interest of Arrow-derived polarimetric observables which may be of interest in multiple biomedical scenarios such as early pathology detection and diagnosis or enhanced visualization of different structures for clinical applications.

Gray and white matter discrimination in ex-vivo cow brain tissue through polarimetric-based pseudocoloration methods

“…In the literature we can find pseudo-colored approaches using different probability functions. [12][13][14] In this case, to construct the pseudocolored images we have chosen the functions presented in sec.2.1: the Normal distribution based algorithm and the Cauchy probabilistic function based algorithm. In addition, by means of the β parameter, which allows to variate the FWHM of the functions, we can obtain highly satisfying results for tissue identification.…”

“…In addition, the study of the polarimetric observables can be extended for the implementation of pseudo-colored methods. [12][13][14] These methods take profit of polarimetric observables to construct improved images based on these characteristics, enhancing the visualization and facilitating the automatic detection of certain structures in biological samples. For instance, different structures in tissues 12,14,15 or pathologies in plants.…”

“…[12][13][14] These methods take profit of polarimetric observables to construct improved images based on these characteristics, enhancing the visualization and facilitating the automatic detection of certain structures in biological samples. For instance, different structures in tissues 12,14,15 or pathologies in plants. 13 In this work we want to inspect the suitability of a set of polarimetric observables related to dichroism, birefringence and depolarization to distinguish various tissue classes within a sample.…”