Subharmonic performance of contrast microbubbles: an experimental and numerical investigation

The diagnostic capabilities of ultrasound imaging can be improved with contrast-specific nonlinear imaging modalities such as harmonic and subharmonic imaging. The subharmonic performance of the ultrasound contrast agent Sonazoid/sup /spl reg// (Amersham Health, Oslo, Norway) has been investigated experimentally and numerically for the implementation of subharmonic imaging. Strong subharmonic responses were observed from Sonazoid microbubbles in vitro, in vivo and numerically. In conclusion, the scattered subharmonic signal amplitude increases with the total energy within each insonation pulse and depends strongly on the polarity of short insonation pulses.