Characterization of an Array-Based Dual-Frequency Transducer for Superharmonic Contrast Imaging
Autor: | F. Stuart Foster, Jianhua Yin, Paul A. Dayton, Guofeng Pang, Jing Yang, Claudia Carnevale, Thomas M. Kierski, Isabel G. Newsome, Emmanuel Cherin, Christine E. M. Demore |
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Rok vydání: | 2021 |
Předmět: |
Beamforming
Acoustics and Ultrasonics Focus (geometry) Acoustics Transducers Contrast Media 01 natural sciences Article Imaging phantom Mice 0103 physical sciences Animals Electrical and Electronic Engineering 010301 acoustics Instrumentation Ultrasonography Physics Microbubbles Subharmonic function Phantoms Imaging business.industry Ultrasound Angiography Transducer Harmonic Clutter business |
Zdroj: | IEEE Trans Ultrason Ferroelectr Freq Control |
ISSN: | 1525-8955 0885-3010 |
Popis: | Superharmonic imaging with dual-frequency imaging systems uses conventional low-frequency ultrasound transducers on transmit, and high-frequency transducers on receive to detect higher order harmonic signals from microbubble contrast agents, enabling high-contrast imaging while suppressing clutter from background tissues. Current dual-frequency imaging systems for superharmonic imaging have been used for visualizing tumor microvasculature, with single-element transducers for each of the low- and high-frequency components. However, the useful field of view is limited by the fixed focus of single-element transducers, while image frame rates are limited by the mechanical translation of the transducers. In this article, we introduce an array-based dual-frequency transducer, with low-frequency and high-frequency arrays integrated within the probe head, to overcome the limitations of single-channel dual-frequency probes. The purpose of this study is to evaluate the line-by-line high-frequency imaging and superharmonic imaging capabilities of the array-based dual-frequency probe for acoustic angiography applications in vitro and in vivo . We report center frequencies of 1.86 MHz and 20.3 MHz with −6 dB bandwidths of 1.2 MHz (1.2–2.4 MHz) and 14.5 MHz (13.3–27.8 MHz) for the low- and high-frequency arrays, respectively. With the proposed beamforming schemes, excitation pressure was found to range from 336 to 458 kPa at its azimuthal foci. This was sufficient to induce nonlinear scattering from microbubble contrast agents. Specifically, in vitro contrast channel phantom imaging and in vivo xenograft mouse tumor imaging by this probe with superharmonic imaging showed contrast-to-tissue ratio improvements of 17.7 and 16.2 dB, respectively, compared to line-by-line micro-ultrasound B-mode imaging. |
Databáze: | OpenAIRE |
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