Use of a nonlinear perturbation approach for in vivo breast lesion characterization by multiwavelength time-resolved optical mammography.

A novel nonlinear perturbation model was successfully applied to the in vivo characterization of breast lesions (cysts and tumors) after detection by multi-wavelength time-resolved optical mammography. The model relies on the method of Padé approximants and consists in a nonlinear approximation of time-resolved transmittance curves in the presence of an inclusion. Tissue constituents (blood volume, blood oxygen saturation, lipids and water content) were estimated for both the bulk and the lesion areas. Cysts were reported to have high water content while tumors showed increased blood content as compared to bulk tissue.