Using speckle to measure tissue dispersion in optical coherence tomography.

Tissue dispersion could be used as a marker of early disease changes to further improve the diagnostic potential of optical coherence tomography (OCT). However, most methods to measure dispersion, described in the literature, rely on the presence of distinct and strong reflectors and are, therefore, rarely applicable . A novel technique has been developed which estimates the dispersion-induced resolution degradation from the image speckle and, as such, is applicable .

Lateral resolution improvement of oversampled OCT images using Capon estimation of weighted subvolume contribution.

A novel technique for lateral resolution improvement in optical coherence tomography (OCT) is presented. The proposed method is based on lateral oversampling of the image. The locations and weights of multiple high spatial resolution sub-volumes are calculated using a Capon estimator assuming each contributes a weighted portion to the detected signal.

Axial resolution improvement by modulated deconvolution in Fourier domain optical coherence tomography.

A novel technique for axial resolution improvement in Fourier domain optical coherence tomography (FDOCT) is presented. The technique is based on the deconvolution of modulated optical coherence tomography signals. In FDOCT, the real part of the Fourier transform of the interferogram is modulated by a frequency which depends on the position of the interferogram in k space.

Optical coherence tomography axial resolution improvement by step-frequency encoding.

A novel technique for axial resolution improvement of Optical Coherence Tomography (OCT) systems is proposed. The technique is based on step-frequency encoding, using frequency shifting, of the OCT signal. A resolution improvement by a factor of approximately 7 is achieved without the need for a broader bandwidth light source.

Scatterer size-based analysis of optical coherence tomography images using spectral estimation techniques.

A novel spectral analysis technique of OCT images is demonstrated in this paper for classification and scatterer size estimation. It is based on SOCT autoregressive spectral estimation techniques and statistical analysis. Two different statistical analysis methods were applied to OCT images acquired from tissue phantoms, the first method required prior information on the sample for variance analysis of the spectral content.

AM-FM techniques in the analysis of optical coherence tomography signals.

The subtle tissue changes associated with the early stages of malignancies, such as cancer, are not clearly discernible even at the current, improved, resolution of optical coherence tomography (OCT) systems. However, these changes directly affect the spectral content of the OCT image that contains information regarding these unresolvable features. Spectral analysis of OCT signals has recently been shown to provide additional information, resulting in improved contrast, directly related to scatterer size changes.