Assessment of ultrasonic properties of an agarose phantom at the frequency range 2.25 MHz to 10 MHz

Abstract

Abstract Agarose-based phantoms are widely used to evaluate ultrasonic equipment used for diagnosis. Many studies report phantom’s ultrasonic characteristics as a function of frequency, mainly sound velocity and attenuation, but a metrological approach is not widely spread. The current paper reports attenuation coefficient (Att-c) and speed of sound (SoS) in an agarose-based phantom as a function of the diagnostically used frequency, ranging from 2.25 MHz to 10 MHz, at 21 °C. The pulse-echo method was applied to measure the ultrasonic properties. The measurements were performed under repeatability conditions (no = 4) and the expanded uncertainties of the measurements were estimated thereafter. It was observed that there was no statistical difference among the values of SoS (average of 1,540.3 m s-1) for all frequencies, in which the maximum E_n = 0.98. The SoS result with the highest uncertainty was of 1,538.7 m s-1 ± 3.8 m s-1 (k = 2; coverage probability p = 0.95). Att-c increases as a power function of frequency (Att-c = f 109; α0 = 0.573; R2 = 0.9995. A survey of the literature was made and it was found that Att-c values obtained in this research are consistent with the previously reported. Based on the SoS, this study draws attention to the importance of performing a statistical test to assess the consistency of the results.