Effect of acoustic intensity on lesion formation. (A) Volume, (B) distortion, and (C) center shift of lesions as a function of continuous wave acoustic intensity. All samples were initially insonified with a 30-cycle, 6.4 W vaporization pulse. The acoustic intensity had a significant effect on the lesion volume, distortion, and center shift in gel phantoms containing PSNE. Error bars represent the standard deviation from five measurements.