Spectral diagnosis and imaging

Summary form only received as follows: Recent research indicates that laser spectroscopy can be used to diagnose disease and extract histochemical information. Reflectance, absorption, fluorescence and Raman scattering in the infrared, visible and ultraviolet can all be used without the use of exogenous (external) dyes. Data can be obtained in real time during clinical procedures using optical fiber contact probes, needles, and endoscopic imaging techniques. Biopsy is not required, and the methods are non-perturbative. Laser-induced fluorescence has been most widely studied. In addition, vibrational techniques have recently begun to be explored. Raman spectroscopy appears to be the most promising of these. Signals are weak but information content is high, and new technology opens the possibility of clinical application of such techniques. Clinical results and their biophysical basis are presented. Prospects for spectral imaging in two and three dimensions are also discussed