Ex vivo photometric and polarimetric multilayer characterization of human healthy colon by multispectral Mueller imaging

Abstract

Healthy human colon samples were analyzed ex vivo with a multispectral imaging Mueller polarimeter operating from 500 to 700 nm in a backscattering configuration with diffuse light illumination impinging on the innermost tissue layer, the mucosa. The intensity and polarimetric responses were taken on whole tissues first and after progressive exfoliation of the outer layers afterwards. Moreover, these measurements were carried out with two different substrates (one bright and the other dark) successively placed beneath each sample, allowing a reasonably accurate evaluation of the contributions to the overall backscattered light by the various layers. For the shorter investigated wavelengths (500 to 550 nm) the major contribution comes from mucosa and submucosa, while for the longer wavelengths (650 to 700 nm) muscular tissue and fat also contribute significantly. The depolarization has also been studied and is found to be stronger in the red part of the spectrum, mainly due to the highly depolarizing power of the muscular and fat layers.

Polarised stereo endoscope and narrowband detection for minimal access surgery

“…However, the tissue examined in this paper was, by comparison, structurally homogenous and isotropic. This is supported by previous work by our group and others [8,19], which has shown that depolarisation dominates over retardance and diattenuation, making it unlikely that additional contrast would be seen by rotating the incident polarisation angle. Indeed, Mueller polarimetric analysis of bowel tissue has shown it to be a partial depolariser with insignificant diattenuation and retardance [20].…”

Mueller polarimetric imaging for surgical and diagnostic applications: a review

“…It was demonstrated that early stage cancerous human colon is less depolarizing than healthy colon through ex vivo measurements with a multispectral Mueller polarimetric imaging system [14]. Using the same system, it was also shown that tissue depolarization could provide useful image contrast to quickly identify the stage of colon cancer development [16], and the relevant histopathological reasons were discussed in terms of tissue layers [17] and tissue absorption and scattering [15]. The system was also found to be a promising tool to evaluate colon cancer progression and residual cancerous tissue after radio-chemical therapy [20].…”

“…The characteristic polarization information of interest is carried by a 4 3 4 matrix named a Mueller matrix and this can be experimentally obtained from Mueller polarimetry and polarimetric imaging. In recent years, an increasing number of biomedical applications of Mueller polarimetric imaging techniques have been proposed [5], e. g. oral cancerous legion detection [13], cervical cancer and colon cancer detection and staging [12,[14][15][16][17][18][19], assessment of cancer therapy [20], partial bladder obstruction diagnosis [21], guiding mass spectrometry for instant pathology [22], characterizing collagen fibres [23], and these have demonstrated advantages over polarization blind imaging.…”

Characterizing microstructures of cancerous tissues using multispectral transformed Mueller matrix polarization parameters

“…Apart from polarization, spectral features of the scattered light also carry information on the microstructure of biological samples, therefore can be applied in diagnosis of cancerous tissues [19]. Studies have shown that combining polarization and spectral techniques can provide more powerful tools for cancer diagnosis [20][21][22][23][24].…”