Optical Coherence Elastography technique for imaging in vivo the mechanical properties of the retina of animal models

Assessing the mechanical properties of biological tissue offers valuable insights for disease diagnosis and monitoring, as tissue stiffness has long been recognised as a key biomarker for certain diseases.

Optical coherence elastography (OCE) is an innovative biomedical imaging technique that uses optical coherence tomography (OCT) to acquire images of biological tissue to assess its biomechanical properties. When a mechanical load is applied, the tissue deforms in response. OCE relies on sequential OCT scans to detect sub-micrometric displacements in tissue structure. There are various implementations of OCE, differing in the type of mechanical loading applied to the tissue, the OCT scanning protocol, and the method used to measure tissue deformation.

Mathematical modeling in elastography typically involves two main steps. The first step focuses on using OCT images for the reconstruction of the displacement field in order to estimate the mechanical response of tissue under stress. The second step utilizes this mechanical response estimation to reconstruct the tissue’s internal mechanical properties.

The main challenges in this line of research involve the development of efficient methods, capable of handling noisy data and accurately recover the tissue’s mechanical properties, addressing the elastography inverse problem. Creating robust techniques for computing tissue displacements in OCE is also critical, as these measurements directly impact the precision with which tissue elastic properties are estimated.

Although the project deals only with the development of the imaging technique and associated instrumentation, the ultimate goal is to discover techniques with enough sensitivity to detect early signs of neurodegeneration and define biomarkers based on mechanical properties of the retina that allow the early detection, prior to clinical manifestations, of neurodegenerative processes.

This research project involves an interdisciplinary team at the University of Coimbra with background on Physics, Engineering and Mathematics and expertise on OCT and US instrumentation, optical modelling of the retina, image processing and reconstruction methods, numerical methods and inverse problems.

Sílvia Barbeiro
CMUC, Department of Mathematics, University of Coimbra, Portugal

Miguel Morgado
CIBIT/ICNAS, Department of Physics, University of Coimbra, Portugal

Webpage

https://sites.google.com/view/migmorgado/home/on-going-projects/elastooct

Project reference

• FCT - Project PTDC/EMD-EMD/32162/2017

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