LAUSR

The utility of echo decorrelation imaging feedback for real-time control of in vivo ultrasound thermal ablation was assessed in rabbit liver with VX2 tumor. High-intensity focused ultrasound (HIFU) and unfocused (bulk) ablation was performed using 5 MHz linear image-ablate arrays. Treatments comprised up to nine lower-power sonications, followed by up to nine higher-power sonications, ceasing when the average cumulative echo decorrelation within a control region of interest exceeded a predefined threshold (−2.3, log10-scaled echo decorrelation per millisecond, corresponding to 90% specificity for tumor ablation prediction in previous in vivo experiments [Fosnight et al., Ultrasound Med. Biol. 43:176-186, 2017]). This threshold was exceeded in all cases for both HIFU (N = 13) and bulk (N = 8) ablation. Controlled HIFU trials achieved significantly smaller average lesion width compared to previous uncontrolled trials. Both controlled HIFU and bulk ablation trials required significantly less treatment time t...