The Speed of Sound and Attenuation of an IEC Agar-Based Tissue-Mimicking Material for High Frequency Ultrasound Applications

Abstract

This study characterized the acoustic properties of an International Electromechanical Commission (IEC) agar-based tissue mimicking material (TMM) at ultrasound frequencies in the range 10–47 MHz. A broadband reflection substitution technique was employed using two independent systems at 21°C ± 1°C. Using a commercially available preclinical ultrasound scanner and a scanning acoustic macroscope, the measured speeds of sound were 1547.4 ± 1.4 m∙s−1 and 1548.0 ± 6.1 m∙s−1, respectively, and were approximately constant over the frequency range. The measured attenuation (dB∙cm−1) was found to vary with frequency f (MHz) as 0.40f + 0.0076f2. Using this polynomial equation and extrapolating to lower frequencies give values comparable to those published at lower frequencies and can estimate the attenuation of this TMM in the frequency range up to 47 MHz. This characterisation enhances understanding in the use of this TMM as a tissue equivalent material for high frequency ultrasound applications.

Subharmonic, Non-linear Fundamental and Ultraharmonic Imaging of Microbubble Contrast at High Frequencies

“…Transmit signals for SH images were at 30 MHz, whereas transmit frequencies for NF and UH images were 22 and 15 MHz. Attenuation of the acoustic wave in the tissue-mimicking material is about 1 dB/MHz/cm of propagation (Sun et al 2012). Therefore, the amplitude of the excitation burst at 30 MHz used for SH imaging is 2.5 times (8 dB) more attenuated than the bursts used for NF imaging (22 MHz).…”

Development of a custom biological scaffold for investigating ultrasound-mediated intracellular delivery

“…A variety of biomimetic platforms have been developed and evaluated for ultrasound studies, based on gellan-gum [46], agar [47] and polyacrylimide [48]. The vast majority of experimental setups used for in vitro investigations on the effects of ultrasound on cells (including sonoporation) however have been carried out in plastic well plates [15][16][17][18]49].…”

Quantitative sonoelastography of the uterine cervix by interposition of a synthetic reference material

“…The perfect reference material would have no attenuation, the speed of sound would be about 1540 m/s , and the stiffness should not be too different from that of the uterine cervix. Agar was considered since the speed of sound in agar is almost 1540 m/s and the attenuation is low. However, in our study this proved to be too breakable, even though a previous study showed that agar was able to resist high pressure .…”