Abstract
The early stages of malignant diseases, such as cancer, are characterized by cellular and microstructural changes which define both the diagnosis and the prognosis of the disease. Unfortunately, at the current resolution of Optical Coherence Tomography (OCT), such changes associated with early cancer are not clearly discernible. However, spectral analysis of OCT images has recently shown that additional information can be extracted from those signals, resulting in improved contrast which is directly related to scatterer size changes. Amplitude Modulation – Frequency Modulation (AM-FM) analysis is a fast and accurate technique which can also be applied to the OCT images for estimation of spectral information. It is based on the analytic signal of the real data, obtained using a Hilbert Transform, and provides the instantaneous amplitude, phase, and frequency of an OCT signal. The performance of this method is superior to both FFT-based and parametric (e.g. autoregressive) spectral analysis providing better accuracy and faster convergence when estimating scatterer features. Since disease tissues exhibit variations in scatterer size and thus also exhibit marked differences in spectral and phase characteristics, such advanced analysis techniques can provide more insight into the subtle changes observed in OCT images of malignancy. Therefore, they can make available a tool which could prove extremely valuable for the investigation of disease features which now remain below the resolution of OCT and improved the technology’s diagnostic capabilities.
© 2009 OSA/SPIE
PDF ArticleMore Like This
Andreas Kartakoulis and Costas Pitris
6627_20 European Conference on Biomedical Optics (ECBO) 2007
Chih-Wei Lu, Han-Mo Chiu, and Chia-Wei Sun
7372_16 European Conference on Biomedical Optics (ECBO) 2009
P. Meystre, G. Reiner, and E. M. Wright
WA5 Instabilities and Dynamics of Lasers and Nonlinear Optical Systems (IDLNOS) 1985