OPTICAL COHERENT TOMOGRAPHY IN ENDOSCOPIC DIAGNOSTICS OF NEOPLASTIC FORMATIONS OF THE GASTROINTESTINAL TRACT

V.A. DUVANSKIY, M.V. KNYAZEV

SSC of Laser Medicine FMBA of Russia RPFU, Moscow, RUSSIA

Introduction. The aim of our study was to evaluate the capabilities of optical coherent tomography (OCT) in diagnosis esophageal, gastric and colonic neoplasms.

Materials and methods. Endoscopic OCT was performed in 135 patients, 55 during the examation of the esophagus and stomach, and 80 of the colon. During the conduct of an endoscopic OCT, videoendoscopes of "Olympus" company Exera GIF 2T160 and optical coherent tomography, developed in the IAP RAS (Nizhny Novgorod) were used. Technical specifications of the device: wavelength - 1300 nm; power source - 2-4 mW, power at the facility - 0.75 mWt, the spatial resolution - 10-20 microns, scanning depth 1-2 mm, lateral scan range - 1.8 mm ; scanning frequency 70-150 Hz. A probe equipped with a visible red pilot (630 nm, 0.1 mW) was used in the study. The evaluation of the informative value of OCT was performed by comparing interpretations of the obtained images and results of histological studies. OCT - research method based on measuring of the reflected signal of low-intensity coherent light in the infrared range, used as the probe radiation for the transmission of biological tissues. Optical images were assessed as to the brightness, contrast, border characteristics, optical inhomogeneity, structure, layering and rate of fading signal.

Results. Tomograms obtained during OCT for normal mucosa are characterized by structural and nonhomogeneous image, the rate of fading of the tomographic signal is slow; sites of dysplasia of the mucous membrane is structureless, with preserved optical inhomogeneity, the rate of fading of the tomographic signal is moderate. OCT images in cancer are structureless, homogeneous, the rate of fading of the tomographic signal ranges between moderate and high. Typical signs of atrophy of the gastric mucosa were thinning of mucous layer, homogeneity of the structure and visualization not less than two layers.

Conclusion. Analysis of the results of study shows that the normal and pathologically changed mucosa of stomach and colon is visualized differently on tomograms. OCT is informative in the endoscopic diagnosis of pathology of the gastrointestinal tract and can be used as “optical biopsy” in endoscopic examinatiom of the gastrointestinal tract.

Date: 2014-12-28; view: 886