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Biomedical applications of polarimetric imaging contrast. Initial studies for scattering media and human tissues

Abstract : Improving the visualization of dysplastic regions of uterine cervix in vivo is essential for a better identification of the locations to biopsy and a better definition of the boundaries of the anomalous regions to be surgically removed. For this purpose we propose an innovative optical technique based on multispectral full Mueller polarimetric imaging in backscattering configuration. Measurements on ex vivo samples were performed to define the best acquisition procedures and data treatments for in vivo diagnosis. As this optimization requires thorough understanding of polarimetric contrasts between healthy and anomalous tissues, we simulated the propagation of polarized light in multilayer structures representative of real tissues. These structures typically involve an uppermost layer describing the epithelium and/or superficial connective tissue, on top of a totally depolarizing lambertian surface lumping the contribution of deeper layers. The simulations were performed by using a Monte Carlo code which has been modified and adapted to our topic. We thus showed that the contribution of the cell nuclei is in fact quite small in the backscattering geometry. For connective tissue, collagen fibers were modelled as 200 nm radius scatterers. Once more this contribution alone could not reproduce the main experimental features. Very small scatterers (50 nm typical radius) have to be included to account for the Rayleigh-like polarimetric response observed in all tissues, both healthy and diseased. These scatterers may be representative of proteins, whose concentration seems to be a crucial parameter to account for the observed contrasts. In this sense, polarimetric imaging may reflect not only the tissue morphology as seen by optical microscopy, but also its physiological state, which may be a very important point for cancer detection and staging.
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https://pastel.archives-ouvertes.fr/pastel-00652201
Contributor : Maria Rosaria Antonelli <>
Submitted on : Thursday, December 15, 2011 - 9:57:08 AM
Last modification on : Wednesday, March 27, 2019 - 4:20:03 PM
Long-term archiving on: : Friday, March 16, 2012 - 2:23:16 AM

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Maria Rosaria Antonelli. Biomedical applications of polarimetric imaging contrast. Initial studies for scattering media and human tissues. Medical Physics [physics.med-ph]. Ecole Polytechnique X, 2011. English. ⟨pastel-00652201⟩

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