Displacement field estimation from OCT images utilizing speckle information with applications in quantitative elastography

Ekaterina Sherina,Wolfgang Drexler,Simon Hubmer,Lisa Krainz,Otmar Scherzer

doi:10.1088/1361-6420/abaf65

Abstract

In this paper, we consider the problem of estimating the internal displacement field of an object which is being subjected to a deformation, from optical coherence tomography images before and after compression. For the estimation of the internal displacement field we propose a novel algorithm, which utilizes particular speckle information to enhance the quality of the motion estimation. We present numerical results based on both simulated and experimental data in order to demonstrate the usefulness of our approach, in particular when applied for quantitative elastography, when the material parameters are estimated in a second step based on the internal displacement field.

Highlights

The present paper is concerned with Quantitative Elastography from Optical Coherence Tomography (OCT) measurements
We consider in particular the displacement estimation step in two-step approaches to OCT elastography; see e.g. [1, 22, 27, 28, 40, 46, 49] and the references therein
Due to Theorem 3.4, one way of computing the minimizer of the functional F is by solving the variational problem (3.14), which can for example be done via a finite element (FE) method

Summary

Introduction

The present paper is concerned with Quantitative Elastography from Optical Coherence Tomography (OCT) measurements. [13, 22, 27, 28, 29, 40] and the references therein These differ for example in the employed deformation (e.g., quasi-static, harmonic, transient), the underlying elasticity model (e.g., linear, viscoelastic, hyperelastic), the way the deformation is measured (only on the boundary, or everywhere inside the sample using, e.g., ultrasound, magnetic resonance, or optical imaging techniques), and whether a one-step approach (i.e., reconstructing the material parameters directly from the internal images) or a twostep approach (i.e., first estimating the displacement field from the images and computing the material parameters) is used. The axial component of the displacement field can be measured directly via phase-sensitive OCT, given that this modality is available This is usually not enough to obtain quantitative material parameter reconstructions, since important information is contained in the other field components. A standard technique in this context is the normalized cross-correlation method based on so-called speckle in the OCT images [14, 37, 40, 44]

Methods

Results

Conclusion