Shear wave OCE (SW-OCE) is a novel technique that relies on the detection of the localized shear wave speed to map
tissue elasticity. In this study, we demonstrate high speed imaging to capture single-shot transient shear wave
propagation for SW-OCE. The fast imaging speed is achieved using a Fourier domain mode-locked (FDML) high-speed
swept-source OCT (SS-OCT) system. The frame rate of shear wave imaging is 16 kHz, at an A-line rate of ~1.62 MHz,
enabling the detection of high-frequency shear waves up to 8 kHz in bandwidth. Several measures are taken to improve
the phase-stability of the SS-OCT system, and the measured displacement sensitivity is ~10 nanometers. To facilitate
non-contact elastography, shear waves are generated with the photo-thermal effect using an ultra-violet pulsed laser.
High frequency shear waves launched by the pulsed laser contain shorter wavelengths and carry rich localized elasticity
information. Benefiting from single-shot acquisition, each SWI scan only takes 2.5 milliseconds, and the reconstruction
of the elastogram can be performed in real-time with ~20 Hz refresh rate. SW-OCE measurements are demonstrated on
porcine cornea ex vivo. This study is the first demonstration of an all-optical method to perform real-time 3D SW-OCE.
It is hoped that this technique will be applicable in the clinic to obtain high-resolution localized quantitative
measurements of tissue biomechanical properties.
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