Spectroscopic diagnosis and imaging of invisible pre- XXXX .

@entity5 @entity1 @entity3917 @entity1586
The theme of this paper is the use of optical spectroscopy to diagnose invisible pre- @entity5 in @entity1 undergoing endoscopy and similar medical procedures. We describe three techniques that provide diagnostic information and two instruments to implement them, the FastEEM for studying small regions of tissue and the @entity3917 ( @entity3917 ) imaging system for wide-area surveillance. The FastEEM is an optical fiber clinical device that collects spectra of reflected light and fluorescence at multiple excitation wavelengths from the tissue, all in a fraction of a second. Quantitative information is obtained in real time, without removing the tissue and without the need for staining and fixation. Three types of spectral information are extracted intrinsic fluorescence, diffuse reflectance and elastic light scattering. Each of the three analyses is based on a biophysical model, and each provides complementary quantitative physical and chemical information about cellular/tissue structures. This information is used to make a combined spectral diagnosis, a method we call tri-modal spectroscopy (TMS). Promising clinical studies are being carried out on @entity1 undergoing routine pre- @entity5 surveillance in the oral cavity, the uterine cervix and the gastrointestinal tract. The @entity3917 imaging system provides wide-area spectroscopic images of the epithelium, typically 2 cm in each dimension, depicting the size distribution and chromatin content of the cell nuclei, which are key parameters in diagnosing pre- @entity5 . This instrument is in preclinical stages of development, although a laboratory prototype has been used to create diagnostic images in resected @entity1586 samples. The combination of the TMS/FastEEM and @entity3917 imaging instrument will constitute a powerful new diagnostic tool, with @entity3917 imaging to provide wide area surveillance and the TMS probe to provide detailed information on suspect tissue sites.
