Breast cancer arises either in the lobules or the ducts of the tissue. Structural changes occurring with malignancy manifest as refractive index variations inside the tissue. It is crucial to quantify these depth wise variation in refractive index for early cancer detection. In this study, three types of unstained breast tissue sections - fibrocystic, fibroadenoma, and invasive carcinoma have been examined for the ultra-structural changes using `Fourier domain low coherence interferometry'. The resulting interference spectra of the backscattered light from the front and the rear surface of the sample are Fourier analyzed to provide depth correlation function. The subtle small-scale fluctuations in the Fourier analyzed spectra are then evaluated using Discrete Wavelet Transform (DWT). Daubechies-1 wavelet of DWT is used to calculate the high pass and low pass coefficients. The sixth level low pass coefficients of DWT clearly discriminate among normal, benign, and malignant breast tissue. Skewness and kurtosis values for these coefficients are also able to well distinguish the type of tissues.
Morphological changes in tissue are highly correlated with progression of cancer. Such structural changes lead to fluctuations of refractive index (RI) inside the tissue, which are random and exhibit self-similar properties. Depth distribution in RI of oral tissue samples were studied through Fourier domain low coherence interferometry. A halogen tungsten lamp was used as the source, and an Ocean Optics spectrometer was used for the collection of interference spectra. The experimental system was calibrated using mica sheets of different thick- nesses, polystyrene microspheres and polydimethylsiloxane (PDMS). Multifractal detrended fluctuation analysis (MFDFA) were employed on interference spectra to study and quantify multifractality in depth-wise distribution of the RI in oral tissue sections. The derived multifractal parameters, namely the generalized Hurst exponent and the width of the multifractal spectrum, showed quite significant differences among tissues having three different grades of cancer. The depth-wise variation of the refractive index showed an increase in multifractality with increasing pathological grades of cancer.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.