Full-optical method of local stress standardization to exclude nonlinearity-related ambiguity of elasticity estimation in compressional optical coherence elastography
Alexander A. Sovetsky, Alexander L. Matveyev, Lev A. Matveev, Ekaterina V. Gubarkova, Anton A. Plekhanov, Marina A. Sirotkina, Natalia D. Gladkova, Vladimir Y. Zaitsev
Abstract
Abstract Pronounced elastic nonlinearity intrinsic to many biological tissues makes the Young’s modulus (stiffness) of the tissue strongly dependent on the current strain and stress. The measured modulus may vary several times for rather moderate tissue straining within a few per cent, such strains being quite typical for compressional optical coherence elastography (C-OCE). This pronounced stiffness variability may strongly affect diagnostic conclusions based on the stiffness measurements, so that obtaining reproducible estimates of stiffness in C-OCE is an important and challenging problem. Here, we report a novel full-optical method allowing one to ensure a preselected stress level in C-OCE stiffness mapping. The proposed improved OCE visualization enables reproducible quantitative elastographic visualization even for strongly elastically-nonlinear biological tissues, which is of key importance for reliability of diagnostic applications of C-OCE. In particular, in oncology such OCE technique can be used to control clear tumor resection boundary, express assessment of tumor subtypes and in vivo monitoring of morphological alterations in animal tumor models in response to anti-tumor therapies.