Image sequences of lesion formation in phantoms with PSNE concentrations of 0.000% and 0.008%. The control phantom (PSNE concentration of 0.000%) was sonicated with a 30-cycle tone burst followed by CW for 15 s, and the acoustic intensity was constant at 1,957 W/cm2. The phantom with 0.008% PSNE was sonicated with VP exposure condition (see Table 1). Lesions formed more rapidly in gel phantoms containing PSNE. The white vertical line on each image represents the focal center.