Ultrasonic contrast agent shell rupture detected by inertial cavitation and rebound signals. Academic Article uri icon

Overview

abstract

  • Determining the rupture pressure threshold of ultrasound contrast agent microbubbles has significant applications for contrast imaging, development of therapeutic agents, and evaluation of potential bioeffects. Using a passive cavitation detector, this work evaluates rupture based on acoustic emissions from single, encapsulated, gas-filled microbubbles. Sinusoidal ultrasound pulses were transmitted into weak solutions of Optison at different center frequencies (0.9, 2.8, and 4.6 MHz), pulse durations (three, five, and seven cycles of the center frequencies), and peak rarefactional pressures (0.07 to 5.39 MPa). Pulse repetition frequency was 10 Hz. Signals detected with a 13-MHz, center-frequency transducer revealed postexcitation acoustic emissions (between 1 and 5 micros after excitation) with broadband spectral content. The observed acoustic emissions were consistent with the acoustic signature that would be anticipated from inertial collapse followed by "rebounds" when a microbubble ruptures and thus generates daughter/free bubbles that grow and collapse. The peak rarefactional pressure threshold for detection of these emissions increased with frequency (e.g., 0.53, 0.87, and 0.99 MPa for 0.9, 2.8, and 4.6 MHz, respectively; five-cycle pulse duration) and decreased with pulse duration. The emissions identified in this work were separated from the excitation in time and spectral content, and provide a novel determination of microbubble shell rupture.

publication date

  • January 1, 2006

Research

keywords

  • Albumins
  • Contrast Media
  • Fluorocarbons
  • Image Interpretation, Computer-Assisted
  • Microbubbles
  • Sonication
  • Ultrasonography

Identity

PubMed Central ID

  • PMC2013305

Scopus Document Identifier

  • 33144488785

Digital Object Identifier (DOI)

  • 10.1109/tuffc.2006.1588398

PubMed ID

  • 16471439

Additional Document Info

volume

  • 53

issue

  • 1