title: Acoustic micro-tapping for non-contact 4D imaging of tissue elasticity.
abstract: Elastography plays a key role in characterizing soft media such as biological tissue. Although this technology has found widespread use in both clinical diagnostics and basic science research, nearly all methods require direct physical contact with the object of interest and can even be invasive. For a number of applications, such as diagnostic measurements on the anterior segment of the eye, physical contact is not desired and may even be prohibited. Here we present a fundamentally new approach to dynamic elastography using non-contact mechanical stimulation of soft media with precise spatial and temporal shaping. We call it acoustic micro-tapping (AμT) because it employs focused, air-coupled ultrasound to induce significant mechanical displacement at the boundary of a soft material using reflection-based radiation force. Combining it with high-speed, four-dimensional (three space dimensions plus time) phase-sensitive optical coherence tomography creates a non-contact tool for high-resolution and quantitative dynamic elastography of soft tissue at near real-time imaging rates. The overall approach is demonstrated in ex-vivo porcine cornea.
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.|AGH University of Science and Technology, Krakow, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Ambroziński
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.
authors.forename: Shaozhen
authors.initials: S
authors.lastname: Song
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.
authors.forename: Soon Joon
authors.initials: SJ
authors.lastname: Yoon
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.|Faculty of Physics, Moscow State University, Moscow, 119991, Russia.
authors.forename: Ivan
authors.initials: I
authors.lastname: Pelivanov
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.|Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA.
authors.forename: David
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.
authors.forename: Liang
authors.initials: L
authors.lastname: Gao
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.|Department of Ophthalmology, University of Washington, Seattle, WA 98104, USA.
authors.forename: Tueng T
authors.initials: TT
authors.lastname: Shen
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.|Department of Ophthalmology, University of Washington, Seattle, WA 98104, USA.
authors.forename: Ruikang K
authors.initials: RK
authors.lastname: Wang
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: O'Donnell
mesh_terms: D000818:Animals; D019561:Echocardiography, Four-Dimensional / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005123:Eye / Q000000981:diagnostic imaging*; D013552:Swine; D041623:Tomography, Optical Coherence / Q000379:methods*