Figure 2

A typical example of normalized PSD in gel phantom with vaporized and unvaporized PSNE. The solid line represents the signal with vaporized PSNE, and the dashed line indicates the signal with unvaporized PSNE. The increase in broadband emissions around 2 MHz indicates the presence of inertial cavitation activity. Power density was integrated between 1.7 and 2.1 MHz and used as the IC dose of that segment. This frequency range was chosen due to the bandwidth of the 2-MHz PCD and to minimize the contribution from energy at the 1.6-MHz subharmonic peak.