Abstract

In 1977, Jöbsis first reported biomedical applications of near-infrared spectroscopy (NIRS). NIRS was originally designed for clinical monitoring, and it has also become a useful tool for neuroimaging studies with the so called functional NIRS (fNIRS). In parallel to these developments, diffuse optical tomography (DOT) using near-infrared (NIR) light has been being developed. DOT, one of the most sophisticated optical imaging techniques for observations through biological tissue, allows 3-D quantitative imaging of optical properties which include functional and anatomical information. With DOT, it is expected to be possible to overcome the limitations of conventional NIRS as well as offering the potential for diagnostic optical imaging. However, DOT has been under development for more than 30 years, and the difficulties in development are attributed to the fact that light is strongly scattered and that diffusive photons are used for the image reconstruction.

© 2017 Optical Society of America