Characterization of cervical tissue using Mueller matrix polarimetry.

The cervix is composed of layers of squamous epithelium and connective tissue. The main component of the cervical connective tissue is collagen, which has specific orientations in different parts of the cervix and provides mechanical strength. Cervical pathologies such as cervical intraepithelial neoplasia (CIN), cancer, pregnancy, and spontaneous preterm birth (sPTB) allow for structural remodeling of both squamous epithelium and connective tissue. Mueller matrix (MM) polarimetry is an optical imaging technique that uses polarized light to characterize the morphologic changes in pathological cervix. In this study, advances in MM polarimetry in characterizing cervical tissue and associated pathologies were reviewed. In particular, the basic structure of the MM polarimeter is described. The interaction of polarized light with cervical tissue in terms of polarimetric parameters such as depolarization and birefringence is discussed. The assessment of cervical pathologies including CIN, cancer, pregnancy, and sPTB with MM polarimetry and the underlying reasons that produce the contrast in optical imaging are outlined. The clinical implementation of MM polarimetry, especially the Müller polarimetry colposcope, is also discussed. Finally, the challenges for MM polarimetry in cervical clinics are also speculated.