Mueller Matrix Imaging Research Articles

Probing variations of fibrous structures during the development of breast ductal carcinoma tissues via Mueller matrix imaging.

Recently, we developed a label-free method to probe the microstructural information and optical properties of unstained thin tissue slices based on microscopic Mueller matrix imaging technique. In this paper, we take the microscopic Mueller matrix images of human breast ductal carcinoma tissue samples at different pathological stages, and then calculate and analyze their retardance-related Mueller matrix-derived parameters. To reveal the microstructural features more quantitatively and precisely, we propose a new method based on first-order statistical properties of image to transform the 2D images of Mueller matrix parameters into several statistical feature vectors. We evaluate each statistical feature vector by corresponding classification characteristic value extracted from the statistical features of Mueller matrix parameters images of healthy breast duct tissue samples. The experimental results indicate that these statistical feature vectors of Mueller matrix derived parameters may become powerful tools to quantitatively characterize breast ductal carcinoma tissue samples at different pathological stages. It has the potential to facilitate automating the staging process of breast ductal carcinoma tissue, resulting in the improvement of diagnostic efficiency.

P‐157: Rational Analysis of Self‐Alignment Force of Reactive Additive Monomer with Multiple Methods

Analysis self‐alignment force (SAF) of reactive self‐assembly additive monomer is highly valuable in self‐alignment vertical alignment mode(SAVA), because this force directly influence performance of optoelectronics device. In this work, SAF has been studied by multiple methods, such as atomic force microscopy, mueller matrix imaging polarimeter. Reactive additive monomer and LC molecular were immobilized on the surface of an AFM probe and ITO, respectively. Due to the complexity of the additive monomer‐hydroxy, additive monomer‐LC moluclar interaction, parallel experiments were designed to discriminate specific interactions. The difference of pretilt angle between TFT side and CF side also reveals the difference of SAF at various structure cell. The additive with strong SAF showed well alignment state after forming into optoelectronic device.

Mueller polarimetric microscopic images analysis based classification of breast cancer cells

Mueller polarimetric imaging is considered a potentially powerful technique for probing the microstructural information in the biomedical field. In this study, the Mueller matrix microscopy was adopted to characterize the microstructures of breast cancer cells exhibiting different receptor proteins expressions. To be specific, four types of breast cancer cells were selected, and a suitable method was developed for cell sample preparation to capture clear cell polarimetric images. Subsequently, convolutional neural network was utilized to classify breast cancer cells with different input datasets types, and Mueller matrix elements images achieved the optimal accuracy of 88.3% (10.1% higher than that of ordinary optical images). The proposed technique demonstrated the potential application of Mueller polarimetric images to classify unstained cells harvested from breast cancer cytological biopsies. Furthermore, by immunofluorescence experiments and cytochalasin B treatment, this study verified that the polarization imaging can effectively show the intracellular localization and content of fibrous actin, which is critical to tumorigenesis and metastasis. It was thus indicated that Mueller matrix imaging can also help study the pathological process of breast cancer by displaying fibrous actin variations.

Different orders of scattering through time-resolved Mueller matrix imaging estimates of pre-malignancy in human cervical tissues.

Time-resolved Mueller matrix (MM) imaging polarimetry in transmission mode has been implemented in both epithelium and stromal regions of cervical tissues to explore the various polarization dynamics in connection with the diagnosis of cervical precancer. The picosecond-resolved intensity patterns of various MM elements, resulting from the various orders of scattering, at different time delays provide clear demarcation between the epithelium and stroma of cervical tissue. The time dependent depolarization and retardance maps are seen to differentiate the epithelium from stroma. The average values of time dependent linear, linear-45, and circular depolarization and linear, circular, and scalar retardance parameters in different regimes of scattering from the optically anisotropic stromal region identify the pre-malignancy in cervical tissue. As the disease evolves, time dependent linear depolarization varies to larger values as compared to time dependent circular depolarization. Interestingly, the chirality of the collagen network that rotates the plane of polarized light in either direction in normal samples is limited to only the clockwise direction during the progression of the disease. These results show potential in the early detection and understanding of the mechanisms of morphological changes in cervical cancer development.

Spatial autocorrelation analysis on two-dimensional images of Mueller matrix for diagnosis and differentiation of cervical precancer.

The spatial autocorrelation and correlation map of amplitude and phase anisotropy along with depolarization parameter from the stroma of uterine cervix utilizing their Mueller matrix (MM) images have been reported for early diagnosis of cervical cancer and differentiation of precancerous stages. The comparative results of the evaluation of the spatial autocorrelation over MM images of optically anisotropic collagen structures from normal and various grades of cervical precancer reflect significant alterations which are correlated with the pathological changes. The spatially varying polarizance from different region of anisotropic stromal region gets correlated within a given spatial lag during the precancerous changes. The diattenuation governing elements M12, M13 and M14 clearly discriminate normal and various grades of precancerous cervical tissue through their autocorrelation profile and correlation map. Evaluation of autocorrelation of spatially varying linear birefringence and linear-45 birefringence characterized by MM elements M34 and M43 and M24 and M42 are not found to differ between the precancer grades, indicating that these changes may be arising from highly directional collagen network while the changes displayed by MM elements M23 and M32 faithfully represent that the chirality of the stromal region is compromised as the cervical cancer evolves and only one type of nature dominates.

Characterization of anisotropy of the porous anodic alumina by the Mueller matrix imaging method.

Porous anodic alumina (PAA) is a photonic crystal with a hexagonal porous structure. To learn more about the effects brought by pores on the anisotropy of the PAA, we use the orientation sensitive Mueller matrix imaging (MMI) method to study it. We fabricated the PAA samples with uniform pores and two different pore diameters. By the MMI experiments with these samples, we found that the birefringence is the major anisotropy of the PAA and that there are many small areas with different orientations that formed spontaneously in the process of production on the surface of the PAA. By the MMI experiments at different orientations of the sample with two different pore diameters, we found that the pores affect the birefringence of the sample and the effect increases with the increased inclination of the sample. To further analyze the PAA, we present a symmetrical rotation measurement method according to the Mueller matrix of the retarder. With this method, we can calculate the average refractive index (RI) of birefringence and the orientation of the optical axis of uniaxial crystal. The results also show the effect of the pores on the anisotropy of PAA.

A collinear reflection Mueller matrix microscope for backscattering Mueller matrix imaging

We developed a collinear reflection Mueller matrix microscope by adding polarization state generator (PSG) and polarization state analyzer (PSA) into the illumination and detection optical paths of a commercial metallurgical microscope. It is found that specific efforts have to be made to reduce the artifacts due to the intrinsic polarizations of the optical system, particularly the dichroism due to the 45° beam splitter. We adopt a new calibration method based on numerical reconstruction of the instrument matrix to minimize the artifacts of the beam splitter. Using a reflection mirror as the sample, maximum error in the calibrated Mueller matrix elements is smaller than 0.02. Preliminary test results using electrospinning samples show that the collinear reflection Mueller matrix microscope can effectively minimize the dependence of Mueller matrix to azimuth orientations and enhance the capability for characterizing the microstructural features of anisotropic samples.

Assessment of anisotropy of collagen structures through spatial frequencies of Mueller matrix images for cervical pre-cancer detection.

Analysis of spatial frequency of Mueller matrix (MM) images in the Fourier domain yields quantifying parameters of anisotropy in the stromal region in normal and precancerous tissue sections of human uterine cervix. The spatial frequencies of MM elements reveal reliable information of microscopic structural organization arising from the different orientations of collagen fibers in the connective tissue and their randomization with disease progression. Specifically, the local disorder generated in the normal periodic and regular structure of collagen during the growth of the cervical cancer finds characteristic manifestation in the Fourier spectrum of the selected Mueller matrix elements encoding the anisotropy effects through retardance and birefringence. In contrast, Fourier spectra of differential polarization gated images are limited to only one orientation of collagen. Fourier spectra of first row elements M11, M12, M13, and M14 and first column elements M11, M21, M31, and M41 discriminates cervical inter-epithelial neoplasia (CIN)-I from normal cervical tissue samples with 95%-100% sensitivity and specificity. FFT spectra of first and fourth row elements classify CIN-I and CIN-II grades of cervical cancerous tissues with 90%-100% sensitivity and 87%-100% specificity. Normal and CIN-II grade samples are successfully discriminated through Fourier spectra of every MM element while that of M31 element arises as the key classifier among normal, CIN-I, and CIN-II grades of cervical cancer with 100% sensitivity and specificity. These results demonstrate the promise of spatial frequency analysis of Mueller matrix images as a novel, to the best of our knowledge, approach for cancer/precancer detection.

Comparing Classification Performance of Mueller Matrix Parameters for Diffuse Materials

This work compares the material classification performance of Mueller matrix polarization imaging to RGB imaging. White painted wood and white fabric samples are selected to create a classification task that is challenging for RGB imaging. A Mueller Matrix Imaging Polarimeter with a 30° full field of view is used to capture the Mueller Matrix images at nominal red, green, and blue wavelengths across multiple specular scatter angles. A Bayesian ideal observer model is used to evaluate classification performance. Performance is quantified by the Area under (AUC) the Receiver Operating Characteristic (ROC) curve. An AUC = 1 is perfect detection and AUC = 0.5 is the performance of guessing. The ensemble average AUC does not exceed 0.70 for RGB irradiance data. The ensemble average AUC for all 16 individual Mueller elements is greater than 0.95. Various combinations of Mueller matrix elements are also tested. Elements related to diattenuation and polarizance are nearly perfect classifiers for large scatter angles but the AUC minimum is 0.60 at 20°. Depolarization index is the highest performing parameter out of all tested polarization parameters for scatter angles ≥70° where AUC ≥0.98.

Imaging Mueller matrix ellipsometry setup for optical nanoform metrology

We designed, realized, and characterised an imaging Mueller matrix ellipsometry setup for the pixelwise measurement of the Mueller matrices in microscope images. Our setup is capable of performing measurements in reflection as well as in transmission in a broad range of angles of incidence for wavelengths between 400 nm and 700 nm. We compared measurements of specially designed nanostructured samples with AFM and SEM measurements as well as with numerical simulations using the finite element method.

Differential Mueller matrix imaging of partially depolarizing optically anisotropic biological tissues

Since recently, a number of innovative polarization-based optical imaging modalities have been introduced and extensively used in various biomedical applications, with an ultimate aim to attain the practical tool for the optical biopsy and functional characterization of biological tissues. The techniques utilize polarization properties of light and Mueller matrix mapping of microscopic images of histological sections of biological tissues or polycrystalline films of biological fluids. The main drawback of currently developed laser polarimetry approaches and Mueller matrix mapping techniques is poor reproducibility of experimental data. This is due to azimuthal dependence of polarization and ellipticity values of most matrix elements to sample orientation in respect to incidence light polarization. Current study aims to generalize the methods of laser polarimetry for diagnosis of partially depolarizing optically anisotropic biological tissues. A method of differential Mueller matrix mapping for reconstruction of linear and circular birefringence and dichroism parameter distributions of partially depolarizing layers of biological tissues of different morphological structure is introduced and practically implemented. The coordinate distributions of the value of the first-order differential matrix elements of histological sections of brain tissue with spatially structured, optically anisotropic fibrillar network, as well as of parenchymatous tissue of the rectum wall with an “islet” polycrystalline structure are determined. Within the statistical analysis of polarization reproduced distributions of the averaged parameters of phase and amplitude anisotropy, the significant sensitivity of the statistical moments of the third and fourth orders to changes in the polycrystalline structure of partially depolarizing layers of biological tissue is observed. The differentiation of female reproductive sphere connective tissue is realized with excellent accuracy. The differential Mueller matrix mapping method for reconstruction of distributions of linear and circular birefringence and dichroism parameters of partially depolarizing layers of biological tissues of different morphological structures is proposed and substantiated. Differential diagnostics of changes in the phase (good balanced accuracy) and amplitude (excellent balanced accuracy) of the anisotropy of the partially depolarizing layers of the vagina wall tissue with prolapse of the genitals is realized. The maximum diagnostic efficiency of the first-order differential matrix method was demonstrated in comparison with the traditional methods of polarization and Mueller matrix mapping of histological sections of light-scattering biological tissues.

Terahertz Mueller Matrix Polarimetry and Polar Decomposition

Mueller matrix imaging, as one of the polarimetric imaging modalities, is an effective tool to achieve imaging enhancement as well as explore fine details of the imaged sample at microwave and optical frequencies. However, little work has been reported at terahertz (THz) frequencies, which could provide an exclusive insight in exploring fine details of biological specimens for their sensitivity to THz absorption due to their various water contents. This article presents a 0.3-THz polarimetric system for Mueller matrix imaging measurements both in reflection and transmission modes. Two experiments are designed to demonstrate the capability of Mueller matrix theory and its polar decomposition in imaging enhancement and properties characterization. The structural similarity index (SSIM) is employed to serve as the metric for image quality assessment, by which the performance of the Mueller matrix imaging is evaluated. The SSIM values of the Mueller matrix could reach as high as 0.9–0.98 for the leaf sample and 0.9 for the indium tin oxide (ITO) target, respectively, whereas that of the raw polarization images could only stabilize at 0.7–0.9 and 0.2–0.4. Furthermore, the SSIM value of the decomposition parameters for the ITO target could reach nearly 1, the maximum value. The imaging results both in visual and analytical perspectives demonstrate successful system integration at THz band. The work paves the way for our exploration of biomedical imaging of tissues and cells at higher THz frequencies in the immediate future.

Effect of curvature of spherical microscopic indentations on the ellipsometric readout

The authors describe and interpret curvature-related changes to the ellipsometric readout. As model system for a concave curvature, a set of three spherical microscopic indents in silicon (100) of different sizes was prepared by instrumented indentation testing using a spherical indenter. For reference, these samples were characterized by AFM to reveal the topography of each structure. The concavelike indents were analyzed by Mueller-Matrix imaging ellipsometry to extract lateral intensity images of 12 elements of the Mueller-Matrix. As a result of the detailed analysis of the image elements m22, m23, and m14, it was possible to correlate intensity changes and symmetry properties to depolarization and cross polarization induced by the edge threshold and the curved surface of the indent.

Distinguishing structural features between Crohn's disease and gastrointestinal luminal tuberculosis using Mueller matrix derived parameters.

Recently, the incidence of inflammatory bowel diseases, especially the Crohn's disease (CD) and gastrointestinal luminal tuberculosis (ITB), has grown rapidly worldwide. Currently there is no general gold standard to distinguish between CD and ITB tissues, which both have tuberculosis and surrounding fibrous structures. Mueller matrix imaging technique is suitable for describing the location, density and distribution behavior of such fibrous structures. In this study, we apply the Mueller matrix microscopic imaging to the CD and ITB tissue samples. The 2D Mueller matrix images of the CD and ITB tissue slices are measured using the Mueller matrix microscope developed in our previous study, then the Mueller matrix polar decomposition and Mueller matrix transformation parameters are calculated. To evaluate the distribution features of the fibrous structures surrounding the tuberculosis areas more quantitatively and precisely, we analyze the retardance related Mueller matrix derived parameters, which show clear different distribution behaviors between the CD and ITB tissues, using the Tamura image processing method. It is demonstrated that the Mueller matrix derived parameters can reveal the structural features of tuberculosis areas and be used as quantitative indicators to distinguish between CD and ITB tissues, which may be useful for the clinical diagnosis.

Structured illumination Mueller matrix imaging

We perform Mueller matrix imaging (MMI) of diffusely scattering phantoms under sinusoidal irradiance of varying spatial frequency. Quantitative polarimetric sensing via MMI completely characterizes a sample's polarimetric properties, while structured illumination (SI) allows for the control of photon path length. Intralipid phantoms were measured with varying absorption and with varying depth to demonstrate photon path length control for Mueller matrix elements. We observe unpolarized intensity, linear polarization, and circular polarization to depend upon spatial frequency differently. Finally, we measured an ex vivo chicken skin sample over a bright and dark substrate to further demonstrate the sensitivity of SI-MMI to depth.

Mueller-matrix-based polarization imaging and quantitative assessment of optically anisotropic polycrystalline networks.

We introduce a Mueller-matrix imaging polarization-based approach for the quantitative digital screening of the polycrystalline structure of fibrillary-based biological tissues in vitro. The morphometric evaluation of histological sections of myocardium was performed utilizing the high-order statistical moments calculated based on the spatial distribution of linear and circular birefringence and dichroism obtained experimentally. We demonstrate that spatial distributions of phase of light and optical anisotropy of scattering inherent to fibrillar networks of myocardium at different necrotic stages can be effectively used as a quantitative marker of stages of myosin fibril degradation. Processing the images of phase of light scattered in biological tissues with high order statistical analysis provides a functional tool for the quantitative characterization of necrotic conditions of the myocardium.

Mueller matrix polarimetry with 3D integral imaging.

In this paper, we introduce the Mueller matrix imaging concepts for 3D Integral Imaging Polarimetry. The Mueller matrix of a complex scene is measured and estimated with 3D integral imaging. This information can be used to analyze the complex polarimetric behavior of any 3D scene. In particular, we show that the degree of polarization can be estimated at any selected plane for any arbitrary synthetic illumination source which may be difficult to produce in practice. This tool might open new perspectives for polarimetric analysis in the 3D domain. Also, we illustrate that 2D polarimetric images are noisier than 3D reconstructed polarimetric integral imaging. To the best of our knowledge, this is the first report on Mueller matrix polarimetry in 3D Integral Imaging.

Quantitative Analysis of 4 × 4 Mueller Matrix Transformation Parameters for Biomedical Imaging

Mueller matrix polarimetry is a potentially powerful technique for obtaining microstructural information of biomedical specimens. Thus, it has found increasing application in both backscattering imaging of bulk tissue samples and transmission microscopic imaging of thin tissue slices. Recently, we proposed a technique to transform the 4 × 4 Mueller matrix elements into a group of parameters, which have explicit associations with specific microstructural features of samples. In this paper, we thoroughly analyze the relationships between the Mueller matrix transformation parameters and the characteristic microstructures of tissues by using experimental phantoms and Monte Carlo simulations based on different tissue mimicking models. We also adopt quantitative evaluation indicators to compare the Mueller matrix transformation parameters with the Mueller matrix polar decomposition parameters. The preliminary imaging results of bulk porcine colon tissues and thin human pathological tissue slices demonstrate the potential of Mueller matrix transformation parameters as biomedical diagnostic indicators. Also, this study provides quantitative criteria for parameter selection in biomedical Mueller matrix imaging.

Broadband extended source imaging Mueller-matrix polarimeter.

An imaging Mueller matrix polarimeter, named the red-green-blue (RGB)950, takes images of medium-sized (tens of centimeters) objects by using a very bright source, large polarization state generator, and high-quality camera. Its broadband extended light source switches between red, green, blue, and near-infrared light to allow taking polarimetric images for comparison with RGB camera images. The large diffuse source makes shadow transitions gradual and spreads out the specular reflected spot into a larger less conspicuous area.

Mueller matrix imaging of prostate bulk tissues; Polarization parameters as a discriminating benchmark.

The polarimetry imaging technique has provided a powerful tool for discriminating normal from cancerous tissues. In this paper, based on the backscattering Mueller matrix imaging of prostate bulk tissues, (received immediately after surgery without any further processing), we have extracted the characteristic features of the Mueller matrix images. In order to provide a quantitative and more accurate comparison, three different methods have been used; the Mueller matrix polar decomposition (MMPD), the Mueller matrix transformation (MMT) and the frequency distribution histograms (FDHs) and their central moment parameters. Comparing different tissues, the results of our study indicate that these methods provide the indicators for the characteristics of the microstructural features of the tissues. The indicators have the potential to distinguish between cancerous and healthy tissues. Determining the polarimetric characteristics of the tissue immediately after surgery and prior to the pathology, and the potential possibility of this technique to be used in vivo as an optical biopsy technique, can significantly reduce the cost and time of diagnosis of cancer.