Compression Optical Coherence Elastography

Abstract

Compression optical coherence elastography (OCE) is a variant of OCE that maps mechanical parameters, or properties of a sample by measuring the deformation in response to quasi-static compressive loading. Relative to other OCE techniques, to date, compression OCE has provided higher acquisition speed, and the capability to scan over wider fields of view. In early compression OCE studies, it was not possible to estimate quantitative mechanical properties, such as elasticity, instead these early studies calculated qualitative mechanical parameters, typically strain. More recently, quantitative compression OCE has been developed to enable the estimation of elasticity, extending its use to broader applications. However, physical contact between the sample, and loading mechanism is typically required, which is a drawback in applications involving delicate tissues, such as ophthalmology. This chapter focuses on the technical development of compression OCE, beginning with the mechanical model used to determine elasticity. An overview of methods for estimating mechanical parameters, and properties; in particular, strain, stress, and elasticity, is provided. In addition, image quality metrics defined to characterize the imaging performance, such as spatial resolution, and sensitivity, are described.