Assessment of collagen absorption and related potential diagnostic applications

The sensitivity to collagen may be useful for diagnostic purposes in mammography, as collagen seems to be involved in the development of breast cancer. Moreover, collagen content is expected to be related to breast density (i.e. breast parenchymal pattern) and its quantification could allow the classification of breast type. Thus we have measured the absorption properties of collagen from 610 to 1040 nm. Absorption spectra of breast from healthy volunteers were then interpreted adding collagen to the other absorbers previously considered (i.e. oxy- and deoxyhemoglobin, water, and lipids). A significant amount of collagen, depending on breast type, is estimated to be present and seems to correlate with breast type. Moreover, adding collagen to the fitting procedure affects remarkably the estimated values of blood content and oxygenation. We have also upgraded our time-resolved multi-wavelength optical mammograph, adding a long wavelength (1060 nm) to improve the spectral information and, in particular, the sensitivity to collagen. Breast measurements on volunteers have recently started.