Home > Research > Polar Instru and Raman Spectr > Biomedical applications
Biomedical applications
Polarimetric Imaging of Human Tissue for Cancer Diagnosis
Experiment
The ex-vivo measurements of both healthy and cancerous colon tissues were performed by Mueller polarimetric imaging system with liquid crystals using diffuse light source at normal incidence and different wavelengths. The typical results of measurement are shown in the figure. All polarimetric images displayed are 5 cm × 5 cm.. Cancerous part of the tissue is shown with blue circles.The experimental data showed that: tumor part of colon tissue is typically less depolarizing compared with the healthy tissue part. The degree of linear polarization (DOPL) of backscattered light is always higher than that of circular polarization (DOPC) for both healthy and cancerous colon tissue.
| |
| (a) Photo of colon tissue, pixels saturated by specularly reflected light are shown in red; (b) Muller matrix images of the same sample taken at lamda = 600 nm. |
Contact : Antonello De Martino - Tatiana Novikova - Rosaria Antonelli - Angelo Pierangelo
Monte Carlo Modeling
The simplest optical model for the epithelial cancer proliferation is based on the increase in the number of large size nuclei within the cells of epithelium layer, reflecting the uncontrolled cell reproduction process. Radiative transfer equation describing the propagation of polarized light within the multi-layered scattering media was solved by Monte Carlo modeling technique. The previously reported simulations and measurements on tissue phantoms (polystyrene spheres suspended in water) revealed that DOCP value exceeds the DOLP value with the particle size increase. Our simulations, however, show that not only particle size but also the optical contrast, the scattering layer thickness and the concentration of the scatterers are all important parameters affecting the DOLP/DOCP ratio.
| |
| Simulated Muller matrices: point source (top) and diffused source (bottom) illumination at lambda=633nm for a water suspension of polystyrene spheres of radius 50nm (left), and radius 1500nm (right) . |
Contact : Antonello De Martino - Tatiana Novikova - Rosaria Antonelli - Angelo Pierangelo