Detecting neoplastic development in the hamster cheek pouch using Fourier Domain Low Coherence Interferometry
Fourier Domain Low Coherence Interferometry (fLCI) is an optical technique that recovers depth-resolved spectroscopic information about scatterers. The current fLCI system utilizes a white light Xe arc lamp source, a 4-f interferometer, and an imaging spectrometer at the detection plane to acquire spectra from 256 adjacent spatial points. This configuration permits the acquisition of ultrahigh depth resolution Fourier domain OCT images without the need for any beam scanning. fLCI has traditionally obtained depth-resolved spectral information by performing a short-time Fourier transform (STFT) on the detected spectra, similar to the processing techniques of spectroscopic OCT. We now employ a dual Gaussian window processing method which simultaneously obtains high spectral and temporal resolution, thus avoiding the resolution trade-off normally associated with the STFT. Wavelength dependent variations in scattering intensity are analyzed as a function of depth to obtain structural information about the probed scatterers. We now verify fLCI's ability to distinguish between normal and dysplastic epithelial tissue using the hamster cheek pouch model. Thirty hamsters will have one cheek pouch treated with the known carcinogen DMBA. At the conclusion of the 24 week treatment period the animals will be anesthetized and the cheek pouches will be extracted. We will use the fLCI optical system to measure the neoplastic transformation of the in situ subsurface tissue layers in both the normal and DMBA-treated cheek pouches. Traditional histological analysis will be used to verify the fLCI measurements. Our results will further establish fLCI as an effective method for distinguishing between normal and dysplastic epithelial tissues. © 2009 SPIE.
