title: Transcranial vibro-acoustography can detect traumatic brain injury, in-vivo: Preliminary studies.
abstract: Vibro-acoustography (VA) uses two or more beams of confocal ultrasound to generate local vibrations within their target tissue through induction of a time-dependent radiation force whose frequency equals that of the difference of the applied frequencies. While VA has proven effective for assaying the mechanical properties of clinically relevant tissue such as breast lesions and tissue calcifications, its application to brain remains unexplored. Here we investigate the ability of VA to detect acute and focal traumatic brain injury (TBI) in-vivo through the use of transcranially delivered high-frequency (2 MHz) diagnostic focused ultrasound to rat brain capable of generating measurable low-frequency (200-270 kHz) acoustic emissions from outside of the brain. We applied VA to acute sham-control and TBI model rats (sham N=6; TBI N=6) and observed that acoustic emissions, captured away from the site of TBI, had lower amplitudes for TBI as compared to sham-TBI animals. The sensitivity of VA to acute brain damage at frequencies currently transmittable across human skulls, as demonstrated in this preliminary study, supports the possibility that the VA methodology may one day serve as a technique for detecting TBI.
authors.affiliation: Department of Bioengineering, Univ. of WA, 1959 NE Pacific St., Box 356470, Seattle, WA 98195, United States; Department of Neurological Surgery, Univ. of WA, 1959 NE Pacific St., Box 356470, Seattle, WA 98195, United States.
authors.forename: Martin W
authors.initials: MW
authors.lastname: Suarez
authors.affiliation: Department of Bioengineering, Univ. of WA, 1959 NE Pacific St., Box 356470, Seattle, WA 98195, United States.
authors.forename: David D
authors.initials: DD
authors.lastname: Dever
authors.affiliation: Department of Bioengineering, Univ. of WA, 1959 NE Pacific St., Box 356470, Seattle, WA 98195, United States.
authors.forename: Xiaohan
authors.initials: X
authors.lastname: Gu
authors.affiliation: Applied Physics Laboratory, Univ. of WA, 1959 NE Pacific St., Box 356470, Seattle, WA 98195, United States.
authors.forename: P
authors.initials: P
authors.lastname: Ray Illian
authors.affiliation: Department of Neurological Surgery, Univ. of WA, 1959 NE Pacific St., Box 356470, Seattle, WA 98195, United States.
authors.forename: Abbi M
authors.initials: AM
authors.lastname: McClintic
authors.affiliation: Department of Bioengineering, Univ. of WA, 1959 NE Pacific St., Box 356470, Seattle, WA 98195, United States; Department of Neurological Surgery, Univ. of WA, 1959 NE Pacific St., Box 356470, Seattle, WA 98195, United States.
authors.forename: Edin
authors.initials: E
authors.lastname: Mehic
authors.affiliation: Department of Bioengineering, Univ. of WA, 1959 NE Pacific St., Box 356470, Seattle, WA 98195, United States; Department of Neurological Surgery, Univ. of WA, 1959 NE Pacific St., Box 356470, Seattle, WA 98195, United States; Applied Physics Laboratory, Univ. of WA, 1959 NE Pacific St., Box 356470, Seattle, WA 98195, United States; Division of Engineering and Mathematics, Univ. of WA Bothell, 1959 NE Pacific St., Box 356470, Seattle, WA 98195, United States. Electronic address: pierre@apl.washington.edu.
authors.forename: Pierre D
authors.initials: PD
authors.lastname: Mourad
mesh_terms: D000818:Animals; D001930:Brain Injuries / Q000000981:diagnostic imaging*; D054459:Elasticity Imaging Techniques / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D008297:Male; D015233:Models, Statistical; D051381:Rats; D017207:Rats, Sprague-Dawley; D014159:Transducers
keywords: Acoustic emissions; Diagnostic focused ultrasound; Frequency compounding; Traumatic brain injury; Vibro-acoustography