Figure 1

MR-guided thermometry of HIFU ablation (15 seconds at 15 Watts) of rat liver following the injection of nanodroplet or microbubble contrast agents. A) the hermometry map was divided into three regions for analysis: B) the target (focus) of the HIFU beam, C) the surface of the animal, and D) the full treated volume. The peak temperature change was calculated for each animal. The gray solid line indicated the mean temperature changed observed when HIFU was applied without an injection of contrast agents, and the dotted lines indicate one standard deviation, *indicates significance (p<0.05) compared to the baseline temperature rise (gray line), †indicates significance (p<0.05) between microbubbles and nanodroplets. (n=3 or 4, except for the 5 minute nanodroplet time point where n=2, data is displayed as the mean +/- S.D.)