ABSTRACT
Diffuse optical imaging is an emerging modality of medical imaging based on the use of near-infrared light. This chapter discusses the underlying principles that govern optical imaging using infrared radiation in instrumental and in numerical reconstruction efforts to pave the way for an effective direct observation of neural activity through the fast optical signal. Optical imaging is the only neuroimaging modality with the potential to measure both the direct neural activity and the indirect hemodynamic responses manifested through the neurovascular coupling. Functional near-infrared spectroscopy is a noninvasive, nonionizing method for functional monitoring and imaging of brain hemodynamics that is used to study human brain function. The image reconstruction transformation is not a model of a physical process but a mathematical function capable of recovering sufficiently good approximations to the original locations in the optical configurations space from the observed locations in the imaging space, in other words from pixel vector values.
