Wavelengths optimization in multi spectral diffuse optical tomography considering uncertainties in absorption spectra

Using multiple lasers in continuous wave diffuse optical tomography has the advantages that scattering and absorption can be distinguished, and that physiological parameters (chromophore concentrations) can be reconstructed. The choice of the laser wavelengths is crucial to ensure a good separability of scattering and chromophores. Current methods to optimize the wavelengths do not consider the sensitivity of the reconstruction result to deviations of extinction coefficients of the chromophores. But since the available absorption spectra for the individual chromophores show significant deviations, it seems to be necessary to take this into account when optimizing the wavelengths. The wavelength optimization approach presented here is an extension of a method of Corlu et al. An additional criterion is introduced. which evaluates the dependence of reconstructed chromophore concentrations on deviations of the absorption coefficients. The wavelengths found by the new approach are compared to those resulting from the original method. Reconstructions of simulated data show the effect of using various spectra for reconstruction with different wavelength sets and illustrate the advantages of the new wavelength sets, leading to less crosstalk between the chromophore concentrations and lower artifacts.