Biomedical Imaging

Optical imaging in biomedicine offers the promise of a safe and economic technology capable of combining imaging with spectroscopy. The ability to spectrally analyse and spatially resolve absorption and fluorescence signals could provide a means to detect and monitor physiological states, including disease, and could ultimately lead to functional imaging. Imaging through biolgical tissue is always degraded by the strong optical scattering in biological tissue and any imaging technique must either discriminate in favour of the unscattered "ballistic" light signal (which is usually extremely weak) or must take account of the multiple scattering in some image reconstruction algorithm based on inverse scattering.

In 1993 a new interdisciplinary research programme was set up at Imperial to investigate novel optical techniques for biomedical imaging using ultrafast/solid-state laser technology. This initially concentrated on (spectrally-resolved imaging through scattering media such as biological tissue, using the techniques of real-time holography in photorefractive media for wide-field ballistic light imaging and optical tomography for imaging through thick tissue with diffuse light. Since then, parallel programmes on the application of adaptive optics to retinal imaging and fluorescence lifetime imaging have been developed to become our main areas of biomedical research. These topics dovetail into our optical microscopy programme, which ranges from theoretical research through development of programmable light sources and adaptive optics to super-resolution for imaging and optical storage and multi-dimensional fluorescence imaging and its application to cell biology, clinical iamging and drug dscovery.

Our biomedical optics programme has exploited the serendipitous spectral overlap of our diode-pumped tunable/ ultrafast laser technology with the "transmission window" of biological tissue. We are working on novel techniques to apply novel and state-of-the-art laser technology to acquire biomedcially useful optical images of (and through) biological tissue.