Application of temporal filters to time resolved data in optical tomography.

This paper addresses the problem of selecting measurement data types suitable for image reconstruction in optical tomography. The principal problem is the necessity to simultaneously reconstruct both the absorption and scatter distribution within an object. This can lead to ambiguities between these two parameters, and result in cross-talk and image artefact. A single-perturbation test problem is used to show that the ability to separate the absorption and scatter maps depends critically on the measurement data types used in the reconstruction, and that significant improvement can be achieved by a combination of suitable data sets. These results are verified by performing reconstructions of a simulated test object with a complex internal structure of embedded inhomogeneities, from which a variety of time-domain forward data sets are calculated. It is shown that dc data are insufficient to separate absorption and scatter features in the images, whereas a combination of moments and Laplace transforms of the temporal measurement signal provides the best reconstruction results of the data types investigated.