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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

TISSUE CHARACTERIZATION BY LOW-FREQUENCY ACOUSTIC WAVES GENERATED BY A SINGLE HIGH-FREQUENCY FOCUSED ULTRASOUND BEAM

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Author(s):
Braz, Guilherme A. [1] ; Baggio, Andre L. [2] ; Agnollitto, Paulo M. [3] ; Grillo, Felipe W. [1] ; Pavan, Theo Z. [1] ; Paula, Francisco J. A. [4] ; Nogueira-Barbosa, Marcello H. [3] ; Cardoso, George C. [1] ; Carneiro, Antonio A. O. [1]
Total Authors: 9
Affiliation:
[1] Univ Sao Paulo, Fac Philosophy Sci & Letters, Dept Phys, Ribeirao Preto, SP - Brazil
[2] Univ Fed Alagoas, Inst Phys, Maceio, Alagoas - Brazil
[3] Univ Sao Paulo, Dept Med Imaging Hematol & Oncol, Ribeiro Preto Med Sch, Ribeirao Preto, SP - Brazil
[4] Univ Sao Paulo, Dept Internal Med, Ribeirao Preto Med Sch, Sao Paulo - Brazil
Total Affiliations: 4
Document type: Journal article
Source: ULTRASOUND IN MEDICINE AND BIOLOGY; v. 47, n. 2, p. 334-344, FEB 2021.
Web of Science Citations: 0
Abstract

The mechanical properties of biological tissues are fingerprints of certain pathologic processes. Ultrasound systems have been used as a non-invasive technique to both induce kilohertz-frequency mechanical vibrations and detect waves resulting from interactions with biological structures. However, existing methodologies to produce kilohertz-frequency mechanical vibrations using ultrasound require the use of variable-frequency, dual-frequency and high-power systems. Here, we propose and demonstrate the use of bursts of megahertz-frequency acoustic radiation to observe kilohertz-frequency mechanical responses in biological tissues. Femoral bones were obtained from 10 healthy mice and 10 mice in which osteoporosis had been induced. The bones' porosity, trabecular number, trabecular spacing, connectivity and connectivity density were determined using micro-computed tomography (mu CT). The samples were irradiated with short, focused acoustic radiation pulses (f = 3.1 MHz, t = 15 mu s), and the low-frequency acoustic response (1-100 kHz) was acquired using a dedicated hydrophone. A strong correlation between the spectral maps of the acquired signals and the mu CT data was found. In a subsequent evaluation, soft tissue stiffness measurements were performed with a gel wax-based tissue-mimicking phantom containing three spherical inclusions of the same type of gel but different densities and Young's moduli, yet with approximately the same echogenicity. Conventional B-mode ultrasound was unable to image the inclusions, while the novel technique proposed here showed good image contrast. (E-mail: adilton@usp.br) (C) 2020 World Federation for Ultrasound in Medicine \& Biology. All rights reserved. (AU)

FAPESP's process: 16/06032-0 - Biomagnetic Studies with Optically Pumped Magnetometers
Grantee:Oswaldo Baffa Filho
Support Opportunities: Regular Research Grants