Optical anisotropy composition of benign and malignant prostate tissues revealed by Mueller-matrix imaging

A Mueller matrix imaging approach is employed to disclose the three-dimensional composition framework of optical anisotropy within cancerous biotissues. Visualized by the Mueller matrix technique spatial architecture of optical anisotropy of tissues is characterised by high-order statistical moments. Thus, quantitative analysis of the spatial distribution of optical anisotropy, such as linear and circular birefringence and dichroism, is revealed by using high-order statistical moments, enabling definitively discriminate prostate adenoma and carcinoma. The developed approach provides greater (>90%) accuracy of diagnostic achieved by using either the 3-rd or 4-th order statistical moments of the linear anisotropy parameters. Noticeable difference is observed between prostate adenoma and carcinoma tissue samples in terms of the extinction coefficient and the degree of depolarisation. Juxtaposition to other optical diagnostic modalities demonstrates the greater accuracy of the approach described herein, paving the way for its wider application in cancer diagnosis and tissue characterization.

3D Mueller matrix mapping of layered distributions of depolarisation degree for analysis of prostate adenoma and carcinoma diffuse tissues

Prostate cancer is the second most common cancer globally in men, and in some countries is now the most diagnosed form of cancer. It is necessary to differentiate between benign and malignant prostate conditions to give accurate diagnoses. We aim to demonstrate the use of a 3D Mueller matrix method to allow quick and easy clinical differentiation between prostate adenoma and carcinoma tissues with different grades and Gleason scores. Histological sections of benign and malignant prostate tumours, obtained by radical prostatectomy, were investigated. We map the degree of depolarisation in the different prostate tumour tissues using a Mueller matrix polarimeter set-up, based on the superposition of a reference laser beam with the interference pattern of the sample in the image plane. The depolarisation distributions can be directly related to the morphology of the biological tissues. The dependences of the magnitude of the 1st to 4th order statistical moments of the depolarisation distribution are determined, which characterise the distributions of the depolarisation values. To determine the diagnostic potential of the method three groups of histological sections of prostate tumour biopsies were formed. The first group contained 36 adenoma tissue samples, while the second contained 36 carcinoma tissue samples of a high grade (grade 4: poorly differentiated-4 + 4 Gleason score), and the third group contained 36 carcinoma tissue samples of a low grade (grade 1: moderately differentiated-3 + 3 Gleason score). Using the calculated values of the statistical moments, tumour tissues are categorised as either adenoma or carcinoma. A high level (> 90%) accuracy of differentiation between adenoma and carcinoma samples was achieved for each group. Differentiation between the high-grade and low-grade carcinoma samples was achieved with an accuracy of 87.5%. The results demonstrate that Mueller matrix mapping of the depolarisation distribution of prostate tumour tissues can accurately differentiate between adenoma and carcinoma, and between different grades of carcinoma. This represents a first step towards the implementation of 3D Mueller matrix mapping for clinical analysis and diagnosis of prostate tumours.

Mueller-matrix of laser-induced autofluorescence of polycrystalline films of dried peritoneal fluid in diagnostics of endometriosis

This research presents investigation results of the diagnostic efficiency of an azimuthally stable Mueller-matrix method of analysis of laser autofluorescence of polycrystalline films of dried uterine cavity peritoneal fluid. A model of the generalized optical anisotropy of films of dried peritoneal fluid is proposed in order to define the processes of laser autofluorescence. The influence of complex mechanisms of both phase (linear and circular birefringence) and amplitude (linear and circular dichroism) anisotropies is taken into consideration. The interconnections between the azimuthally stable Mueller-matrix elements characterizing laser autofluorescence and different mechanisms of optical anisotropy are determined. The statistical analysis of coordinate distributions of such Mueller-matrix rotation invariants is proposed. Thereupon the quantitative criteria (statistic moments of the first to the fourth order) of differentiation of polycrystalline films of dried peritoneal fluid, group 1 (healthy donors) and group 2 (uterus endometriosis patients), are determined.

Statistical analysis of polarization-inhomogeneous Fourier spectra of laser radiation scattered by human skin in the tasks of differentiation of benign and malignant formations

The optical model of formation of polarization structure of laser radiation scattered by polycrystalline networks of human skin in Fourier plane was elaborated. The results of investigation of the values of statistical (statistical moments of the 1st to 4th order) parameters of polarization-inhomogeneous images of skin surface in Fourier plane were presented. The diagnostic criteria of pathological process in human skin and its severity degree differentiation were determined.

Polarization-phase images of liquor polycrystalline films in determining time of death

An optical model for generalized optical anisotropy of polycrystalline networks of albumin and globulin liquor of the human brain has been suggested. The polarization-phase method for spatial and frequency differentiation of linear and circular birefringence coordinate distributions has been analytically substantiated. A set of criteria documenting the dynamics of polarization-phase images of liquor polycrystalline films has been identified in determining time of death.

Fourier polarimetry of human skin in the tasks of differentiation of benign and malignant formations

The optical model of polycrystalline networks of human tissue has been proposed. The values of statistical parameters (statistical moments of the first to fourth order) characterizing the polarization-inhomogeneous images of skin surface in the Fourier domain have been measured. The diagnostic criteria of pathological processes in human skin and the differentiation of its severity degree have been determined.

Polarization-dependent laser autofluorescence of the polycrystalline networks of blood plasma films in the task of liver pathology differentiation

Current research presents the results of the investigation of diagnostic efficiency of laser polarization autofluorescence for the set of endogenous fluorophores of blood plasma polycrystalline films in two spectral regions (0.5-0.53 μm and 0.63-0.67 μm) under the excitation of laser radiation with a wavelength of 0.405 μm. A model of generalized optical anisotropy of protein networks of blood plasma polycrystalline films is proposed for the purpose of defining laser autofluorescence processes. Both phase (linear birefringence and optical activity) and amplitude (linear and circular dichroisms) anisotropies have been considered. Interconnections between the optimal condition of probing beam polarization state and the efficiency of induction laser autofluorescence have been found. Statistical analysis of coordinate distributions of laser polarization autofluorescence intensities is suggested by means of determination of the quantitative criteria (statistical moments of the 1st-4th orders). The efficiency of laser polarization autofluorescence of polycrystalline networks in the task of differentiation of nonalcoholic fatty liver disease and chronic hepatitis of human liver has been analyzed.

Spatial-frequency selection of complex degree of coherence of laser images of blood plasma in diagnostics and differentiation of pathological states of human organism of various nosology

The theoretical background of correlation and phase analysis of laser images of human blood plasma with the spatial-frequency selection of the manifestations of mechanisms of linear and circular birefringence of albumin and globulin is presented. The comparative results of measuring the coordinate distributions of the module of complex degree of coherence (CDC) of laser images of blood plasma taken from the patients of three groups--healthy patients (donors), the patients suffering from the rheumatoid arthritis, and those with stomach cancer (adenocarcinoma)--are shown. The values and ranges of change of the statistical (moments of the first-fourth orders), correlation (excess of autocorrelation functions), and fractal (slopes of approximating curves and dispersion of the extremes of logarithmic dependencies of power spectra) parameters of CDC coordinate distributions are studied. The objective criteria of diagnostics of the pathology and differentiation of the inflammation and oncological state are determined.

Polarization singularities of biological tissues images

The ways to the polarization singularities of the biological tissues images of various morphological structures have been theoretically analyzed. The coordinate distributions of singly (linear states of polarization) and doubly degenerated (circular states of polarization) polarization singularities of the physiologically normal and pathologically changed biological tissues have been experimentally examined. The statistical criteria of diagnostics of the kidney tissue collagenous disease (the third and the fourth statistical moments of the linear density singularity points) have been determined. It was discovered that the process of the pathological change of the kidney tissue morphology leads to the formation of the self-similar (fractal) coordinate distribution of the polarization singularities of its image.

Complex degree of mutual polarization of biological tissue coherent images for the diagnostics of their physiological state

This is the first attempt devoted to the 1st-4th order statistic analysis of the complex degree of mutual polarization of biological tissues coherent images. The ensemble of diagnostic criteria (skewness and kurtosis of two-dimensional distributions of complex degree of mutual polarization) of pathological changes of muscular and connective (skin derma) tissues is defined.

Polarization-correlation mapping of biological tissue coherent images

We investigate the statistical polarization parameters of biological tissue histological section images with different morphological structure. First we outline the results of polarization coordinate mapping and analysis of the statistics of the first to fourth orders of biological tissue image polarization azimuth and ellipticities. Second, we study the statistics of the first to fourth orders of coordinate distributions of the complex degree of mutual polarization (CDMP) of biological tissue images. Finally, we consider the diagnostic possibilities of investigating 2-D distributions of CDMP of images that correspond to physiologically normal and degeneratively and/or dystrophycally changed biological tissues that are being analyzed.

Investigation of the correlation structure of biological tissue polarization images during the diagnostics of their oncological changes

We have considered the theoretical background of biological tissue complex polarization analysis: (1) polarization mapping; (2) polarization-correlation mapping; (3) polarization correlometry. The technique of interferometric measurements of 2D distributions of the complex degree of mutual polarization of biological tissue images has been proposed. The totality of diagnostically urgent interconnections between the statistical and correlation structure of biological tissue polarization images and the optical-geometrical structure of their architectonics has been determined.

Polarization visualization and selection of biotissue image two-layer scattering medium

We analyze and experimentally test the concept of laser polarization biotissue probing. The methods of increasing the SNR in coherent images of the optically anisotropic architectonics of the morphological biotissue structure are considered. The possibilities of polarization selection and contrasting of such images screened by other biotissues are examined. The influence of the depolarization degree of the scattered background on the SNR is investigated. The possibilities of polarization correction of the probing beam for contrasting biotissue images are analyzed.

Wavelet analysis of two-dimensional birefringence images of architectonics in biotissues for diagnosing pathological changes

A method for polarization filtering, correlation processing, and wavelet analysis of coherent images of physiologically normal and necrotically changed (myocardium infarct) muscle tissue is presented. A technique for early optical diagnosis of the appearance of these biological tissues and the course of their degenerative-dystrophic changes is proposed.