The influence of bubble-bubble interactions on contrast agent microbubble-jetting during initial exposure to 200 kHz focused ultrasound

The initial response of contrast agent microbubbles to a burst of 200 kHz focused ultrasound with 1.5 MPa peak-negative pressure amplitude is studied. Directed jetting along the axis of propagation of the ultrasound is observed and the influence of the pressure-gradients on the bubble dynamics evidenced. Furthermore, the influence of nearby bubbles on the jetting behavior is investigated. Bubbles tend to jet towards other bubbles and to be influenced in their dynamics. Moreover, the more bubbles share the same volume, the weaker the jets become.