title: Method for Estimating the Acoustic Pressure in Tissues Using Low-Amplitude Measurements in Water.
abstract: The aim of this study was to evaluate a simple, reliable and reproducible method for accuracy in estimating the acoustic pressure delivered in tissue exposed to ultrasound. Such a method would be useful for therapeutic applications of ultrasound with microbubbles, for example, sonoporation. The method is based on (i) low-amplitude water measurements that are easily made and do not suffer from non-linear propagation effects, and (ii) the attenuation coefficient of the tissue of interest. The range of validity of the extrapolation method for different attenuation and pressure values was evaluated with a non-linear propagation theoretical model. Depending on the specific tissue attenuation, the method produces good estimates of pressures in excess of 10 MPa. Ex vivo machine-perfused pig liver tissue was used to validate the method for source pressures up to 3.5 MPa. The method can be used to estimate the delivered pressure in vivo in diagnostic and therapeutic applications of ultrasound.
authors: Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus.
authors: Christina P
authors: CP
authors: Keravnou
authors: Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus.
authors: Maria-Louisa
authors: ML
authors: Izamis
authors: Department of Bioengineering, University of Washington, Seattle, Washington, USA. Electronic address: maverk@uw.edu.
authors: Michalakis A
authors: MA
authors: Averkiou
mesh_terms: D000818:Animals; D008099:Liver / Q000000981:diagnostic imaging*; D011312:Pressure; D015203:Reproducibility of Results; D013552:Swine; D014465:Ultrasonics; D014463:Ultrasonography; D014867:Water
chemical_list: D014867:Water
keywords: Derating; Drug delivery; Exposimetry; In situ pressure; Liver attenuation; Non-linear distortion; Porcine liver