DETERMINATION of the optical properties of breast tissues using the frequency-resolved transillumination: Basic theory and preliminary results

摘要

Breast tissues can be investigated by means of the frequency-resolved spectroscopy, using the transmittance data. A model based on the Fourier transform of the time-resolved transmittance is firstly established, by considering the slightly compressed breast tissues as a finite homogeneous slab of different thicknesses. Two methods of determining the optical properties of this arrangement are presented. The former allows to use moderate modulation frequency of about 100 MHz, while the second requires a limited frequency range of 10-20 MHz, in accordance with the low frequency approximation. Under these conditions, computations reveal the potential of extracting the main optical tissue properties from the recorded phase angle shift and modulation linked to transmittance data, at fixed operating modulation frequency. In each case, graphical or numerical solutions can provide good estimates of both reduced scattering and absorption coefficients.