The goal of this (University of Pennsylvania) proposed work is to improve the breast tumor diagnostic capabilities of optical spectroscopy and imaging, based on diffusing near-infrared light. New theoretical methodologies will be introduced for image reconstruction within the human breast, and it is planned to develop these theoretical approaches further and test them experimentally. The primary benefit derivable from these ideas is improved breast image fidelity, which in turn will enable clinicians to fully exploit the new spectroscopic and scattering contrast mechanisms available with the optical method, for increased tumor sensitivity and specificity.

Since submission of the proposal, work has experimentally demonstrated the theoretical ideas underlying the near-field Fast Fourier Transform approach. These experiments have produced 2-D projection images of thin objects embedded in infinite media. The apparatus, however, is not well suited for realistic parallel-plate soft breast compression geometries, so construction has been completed of an instrument that is far better suited for these more realistic studies. Various theoretical issues have been explored, including the effects of imaging filters on the reconstructions, and the potential for 3-D reconstruction.