title: Introduction.
abstract: Because of its direct sensitivity to hemodymanic processes, diffuse optical tomography (DOT) has shown great promise as a medical imaging modality for problems including breast tumor detection and functional brain imaging. A key challenge with DOT is the extraction of useful information about the relevant subsurface paramaters, optical absorption and scattering parameters, from fluence data measures at the body surface. In this regard, DOT requires the solution of a generally non-linear, ill-posed inverse problem. The intent of this Focus Issue of Optics Express is to accomplish two tasks. First, we want to highlight the current state-of-the-art in DOT inverse methods. Second, the similarity of the DOT problem to other inverse problems prompts us to include in this issue work from related endeavors. The overall goals then are to broaden the views of those working in DOT in terms of other approaches to their problems and to make the wider inverse problems community more aware of this exciting new area of work.
authors.forename: E
authors.initials: E
authors.lastname: Miller