Abstract

The use of spectroscopy in optical diagnosis is well established and based on the local contrast in the tissue optical properties in diseased tissue versus its surrounding normal. The contrast is provided by endogenous or exogenous chromophores and fluorophores, or through changes in the light scattering properties. Early on it was noted that the optical techniques diagnostic power can be significantly improved when the optical spectrum from the suspected disease tissue volume is considered relative to that of an apparently normal tissue volume. The need for these ratios and relative changes were generally considered due to the variability encountered between different subjects. Little attention was provided to the biological basis of this variability.

© 2009 IEEE