 The ability to separate optical absorption from scattering distinguishes MI from conventional planar reflectance imaging methods. Absorption and scattering maps can be used to characterize the tissues biochemical composition and structure. We have shown that these intrinsic tissue contrast elements vary with tissue types, and their wavelength dependence provides spectral fingerprinting that can be used to delineate the spatial relationships among tissues with different optical properties and can be used to determine the amount of H2O, Hb-total, Hb-deoxy, Hb-O2 Tissue Oxygen Saturation StO2. MI is able to detect the concentration of Hb-total, Hb-deoxy Hb-O2 in absolute amounts in units of millimoles unit volume of tissue measured. MI is also able to determine the percent fraction of mass, which is comprised of H2O in terms of percent mass.11, 14. This feature is critical to the performance of MI as a quantitative diagnostic method and, when combined with its tomographic capabilities, underscores the uniqueness of the method, and its potential use as a monitoring and diagnostic device to evaluate tissue transfer flaps after reconstructive surgery. 