IMAGING BRAIN STRUCTURE AND FUNCTION, INFECTION AND GENE-EXPRESSION IN THE BODY USING LIGHT

Light can be used to probe the function and structure of human tissues . We have been exploring two distinct methods: (i) externally emitting light into tissue and measuring the transmitted light to characterize a region through which the light has passed, and (ii) internally gene rating light within tissue and using the radiated light as a quantitat ive homing beacon. The emitted-light approach falls within the domain of spectroscopy and has allowed for imaging of intracranial haemorrhag e in newborns and of brain function in adults. The generated-light app roach is conceptually parallel to positron emission tomography (PET) o r nuclear medicine scanning, and has allowed for real-time, non-invasi ve monitoring and imaging of infection and gene expression in vivo usi ng low-light cameras and ordinary lenses. In this paper, we discuss re cent results and speculate on the applications of such techniques.