Our efforts this year were concentrated on identifying the practical limitations of diffusing-wave interference spectrophotometry in the context of thick-tissue imaging for clinical application. This goal was achieved by using a combination of theoretical and experimental investigations. We found that although it is possible to determine very precisely the position of a single object embedded deep in a homogeneous medium, the resolution of two or more absorbing (or fluorescent) objects is limited by the width of the diffusive-wave point-spread function, which exceeds about 5 mm at the highest modulation frequencies studied.
