Optical spectroscopy video
Barrett's esophagus may contain areas of precancer (dysplasia) and early cancer that due to their microscopic nature may not be readily visualized at endoscopy. As an adjunct to endoscopy, the goal of optical spectroscopy is to improve identification of these suspicious areas so that targeted biopsies can be obtained.
Optical fibers can be incorporated into standard biopsy forceps to excite the tissue and collect specific light signals that carry diagnostic information about the tissue type. Light signals that do not correlate with abnormal areas would not be biopsied, while light signals that correlate with abnormal areas would be specifically targeted for biopsy.
This animation shows the basic setup of an optical spectroscopic device. Excitation light travels through optical fibers encased in a flexible catheter that is placed in gentle contact with the tissue surface.
At the microscopic level, light interacts with tissue elements in various ways, including the scattering of light by vibrating molecules (Raman scattering). The emitted light signals are collected by the optical catheter connected to a light analyzer (spectrograph) and detector.
Analysis of these light signals provides important information about the microstructure and molecular composition of tissue, and changes in the behavior of these signals can be used to identify abnormal tissue.