1D-2 The Effect of Pulse Length on Acoustic Droplet Vaporization

As a minimally invasive alternative to current treatment of renal cell carcinoma, the use of superheated liquid perfluorocarbon droplets encased in albumin shells has been proposed to treat cancer by occlusion therapy. In response to an applied acoustic field, these droplets, which are small enough to pass through capillaries, vaporize into large gas bubbles that subsequently lodge in the vasculature. This technique, known as acoustic droplet vaporization (ADV) has been shown to successfully reduce blood flow in vivo, but for in situ conditions where attenuation is present, lower acoustic frequency and ADV threshold may be desirable. Thus, this study investigated the role of pulse durations from 20mus-20ms on ADV threshold at a low frequency of 1.44 MHz. Detection by both B-mode ultrasound and passive detection were used. The threshold was found to be 5.5-6 MPa for short microsecond pulses and decreased for millisecond pulses (3.8-4.6 MPa) when using either detector