Preclinical assessment and enhancement of passive acoustic mapping in clinically realistic propagation environments

Abstract

Passive acoustic mapping (PAM) techniques have been developed to detect, localize, and quantify cavitation activity during therapeutic ultrasound treatments. Building on a decade of in vitro and small animal studies, this paper presents a series of pre-clinical experiments and simulations conducted in preparation for an upcoming clinical trial of ultrasound-mediated targeted drug delivery. The effects of tissue attenuation and refraction, array shape and element diffraction, soundspeed uncertainty, and imaging algorithm will be discussed. Critically, techniques will presented for removing factors that would otherwise bias PAM results both within and between patients. Together, the results indicate the potential to significantly enhance both the qualitative and quantitative capabilities of PAM for ensuring clinical therapeutic safety and efficacy. [Work supported by the National Institute for Health Research Oxford Biomedical Research Centre.]Passive acoustic mapping (PAM) techniques have been developed to detect, localize, and quantify cavitation activity during therapeutic ultrasound treatments. Building on a decade of in vitro and small animal studies, this paper presents a series of pre-clinical experiments and simulations conducted in preparation for an upcoming clinical trial of ultrasound-mediated targeted drug delivery. The effects of tissue attenuation and refraction, array shape and element diffraction, soundspeed uncertainty, and imaging algorithm will be discussed. Critically, techniques will presented for removing factors that would otherwise bias PAM results both within and between patients. Together, the results indicate the potential to significantly enhance both the qualitative and quantitative capabilities of PAM for ensuring clinical therapeutic safety and efficacy. [Work supported by the National Institute for Health Research Oxford Biomedical Research Centre.]