Quantitative Frequency-Domain Passive Cavitation Imaging

TLDR

Passive cavitation detection is a key technique for measuring cavitation dynamics, elucidating bioeffects, and guiding ultrasound therapies, and recent advances enable imaging of cavitation activity to give investigators more comprehensive information. The paper outlines methods for performing frequency‑domain delay, sum, and integrate passive imaging. The approach uses array‑based beamforming of cavitation emissions, normalizes Fourier‑transformed data, converts it to acoustic energy, and discusses hardware requirements and alternative imaging strategies. MATLAB examples illustrate the implementation of the proposed imaging methods.

Abstract

Passive cavitation detection has been an instrumental technique for measuring cavitation dynamics, elucidating concomitant bioeffects, and guiding ultrasound therapies. Recently, techniques have been developed to create images of cavitation activity to provide investigators with a more complete set of information. These techniques use arrays to record and subsequently beamform received cavitation emissions, rather than processing emissions received on a single-element transducer. In this paper, the methods for performing frequency-domain delay, sum, and integrate passive imaging are outlined. The method can be applied to any passively acquired acoustic scattering or emissions, including cavitation emissions. To compare data across different systems, techniques for normalizing Fourier transformed data and converting the data to the acoustic energy received by the array are described. A discussion of hardware requirements and alternative imaging approaches is additionally outlined. Examples are provided in MATLAB.