Polarization characteristics of dark-field microscopic polarimetric images of human colon tissue

Abstract

Early detection of cancer through medical imaging has a critical impact on patient survival rates. There are many efforts for detecting early cancer in situ using modalities other than traditional medical optical imaging, which contain additional information over conventional micrographs of surface morphology acquired without staining. We analyzed the Mueller matrix components of human colon tissue obtained with an imaging polarimeter microscope at an illumination wavelength of 442 nm by principal components analysis in order to separate the traditional non-polarized gray image and to investigate the structure of the parameter space of polarization transformation by tissue. We also analyzed Mueller matrix by mapping it to a coherent matrix and performed eigenvalue analysis. The 1 st to 4 th principal components contain 99% of the information present in the images; polarization information contributes less than 10% of the information in the Mueller matrix. In one individual, 80% of the cancer was detected, without the first components which contains traditional non-polarized gray image for traditional diagnosis. Microscopic fine structures were observed, particularly in the 3 rd and 4 th principal components' score images. The entropy image of corrugated cancer tissue was smoother than that of the traditional gray image. There were several abnormal regions identified in adjacent regions of cancer, whose residues exceeded the noise level of the instrument used.

Backscattering Mueller Matrix polarimetry on whole brain specimens shows promise for minimally invasive mapping of microstructural orientation features

“…In concurrent software, also developed for the system by Nikon, a data reduction algorithm is applied which constructs a measurement matrix based on the illumination and detection polarization states and multiplies the pseudoinverse of that with the measured data to find the least-squares optimized Mueller Matrix of the sample (Chipman, 1994), and a series of calibrations are completed to remove artifacts from the illumination and imaging optics (Saito et al, 2019). The instrument which has been previously characterized, validated, and used for human tissue imaging, produces spatial pixel-wise mappings of the sixteen Mueller Matrix components (Fujii et al, 2019;Saito et al, 2019). Exposure times were optimized using the instrument's "autoadjust" setting.…”

Backscattering Mueller Matrix polarimetry on whole brain specimens shows promise for minimally invasive mapping of microstructural orientation features

“…5X magnification was used to capture all images due to its larger field of view and depth of field. The instrument has been previously characterized, validated, and used for human tissue imaging, and produces spatial pixel-wise Frontiers mappings of the sixteen Mueller Matrix components (Fujii et al (2019); Saito et al (2019)). Exposure times were optimized using the instruments "auto-adjust" setting.…”