Figure 2. Coronal US images of one tumor in a single animal obtained during RF ablation. Contrast-enhanced color Doppler US image (A) and contrast-enhanced harmonic power Doppler US image (B) obtained before ablation show intense central (arrowhead in A) and peripheral (arrows) vascular enhancement. Ablation was initiated immediately after the needle (arrowheads in C) was positioned. Fundamental B-mode US image (D) obtained shortly before the end of RF ablation shows an ill-defined hyperechoic lesion (arrows) obscuring the ablation needle, the ablated tumor, and a wide range of surrounding fatty tissue. Contrast-enhanced color Doppler US image (E) obtained after ablation shows no residual perfusion, and contrast-enhanced harmonic power Doppler US image (F) obtained after ablation shows a small area of residual perfusion (arrow). Ablation in this tumor was later found to be incomplete at histopathologic examination. Inset diagrams show plane and direction of view of each image.