Abstract

We discuss an elastography method based on comparison of correlation stability for different parts of sequentially obtained OCT images of the studied strained tissue. The basic idea is that in stiffer regions of a deformed tissue the OCT image is distorted to a smaller degree. Thus, cross-correlation maps obtained using a sliding correlation window for compensation of trivial translational motion of the image parts can reflect the spatial inhomogeneity of the tissue stiffness distribution. An important advantage of the proposed approach is that it allows one to avoid the stage of local strain reconstruction via error-sensitive procedures of numerical differentiation of experimentally determined displacements. Another advantage is that the correlation-stability approach requires that for deformed softer tissue regions, cross-correlation should already be strongly decreased, which intrinsically implies much wider strain range of the method operability compared to other approaches and is favorable for its free-hand implementation. Generally speaking, the approach can be implemented using the cross-correlation of either image features reflecting morphological structure of the tissue or speckle-level cross-correlation. Examples of numerical simulations and experimental demonstrations using both phantom samples and in vivo obtained OCT images are presented.

© 2013 SPIE