Figure 1
Vaporization field (microbubble cloud) and ablation lesion images obtained after applying continuous wave HIFU. HIFU was applied at 1 MHz to albumin-acrylamide gel phantoms containing 5 × 105 PFC ND per milliliter. (A) This ultrasound image shows a cigar-shaped vaporization field generated after 20 s of HIFU at 650 W/cm2 (4 MPa). (B) These optical images show four opaque white ablation lesions located in each transparent gel phantom following the application of HIFU at 650 W/cm2 for 5, 10, 15 and 20 s. Larger lesions can be observed in phantoms treated with longer insonation times. (C) A single ablation lesion cut along its vertical axis, demonstrating the desired cigar shape.