title: Introduction.
abstract: In the past decade, near-infrared sampling of tissue has become a large field of study, which has been called by many names (Photon migration, photon random walk, photon density waves, photon diffusion) encompassing work in spectroscopy and imaging of tissue. In this special issue, the focus is on diffuse optical tomography as it applies to medicine and biology. Diffuse optical tomography involves processing of near-infrared light measurements taken from tissue to create images of the interior.
authors.forename: B
authors.initials: B
authors.lastname: Pogue