High‐accuracy optical coherence elastography digital volume correlation methods to measure depth regions with low correlation

The decreasing correlation of optical coherence tomography (OCT) images with depth is an unavoidable problem for the depth measurement of the digital volume correlation (DVC) based optical coherence elastography (OCE) method. We propose an OCE‐DVC method to characterize biological tissue deformation in deeper regions. The method proposes a strategy based on reliability layer guided displacement tracking to achieve the OCE‐DVC method for the deformation measurement in deep regions of OCT images. Parallel computing solves the computational burden associated with the OCE‐DVC method. The layer‐by‐layer adaptive data reading methods are used to guarantee the parallel computing of high‐resolution OCT images. The proposed method shown in this study nearly doubles the depth of quantitative characterization of displacement and strain. At this depth, the standard deviation of displacement and strain measurements is reduced by nearly 78%. Under nonuniform deformation field, OCE‐DVC method tracked the displacement with large strain gradient in depth region. Compared with conventional DVC, the proposed OCE‐DVC method can measure the deep tissue regions with weak correlation.