<qa>  What is the frequency of illumination and tissue optical properties?The diffusely reflected amplitude of the modulated wave carries both optical property absorption, fluorescence, scattering and depth information. Specifically, the sampling depth of the spatially modulated wave is a function of the frequency of illumination and the tissue optical properties. This shares many analogies to the broadband frequency-domain photon migration FDPM approach. 12, 13 Consequently, measurement of multiple spatial frequencies periodicities allows MI to perform two functions. First, use of a wide range of frequency patterns allows depth-selective imaging and thus tomography of the internal 3D tissue structure. Secondly, it can rapidly and quantitatively map optical absorption, fluorescence yield, and scattering coefficients in near-real time, with high resolution and over a wide field-of-view. 