The use of a microbubble agent to enhance rabbit liver destruction using high intensity focused ultrasound

Liver tissues in New Zealand rabbits were ablated using high intensity focused ultrasound (HIFU, 14300 W/cm(2), 1.0 MHz). The animals were intravenously administered 0.2 ml of microbubble agent in the experimental (n = 20) group and an isovolumetric normal saline solution in the control (n = 27) group before HIFU treatment which was performed as a linear scan. In both groups, the preselected tissue volumes were destroyed without harming the overlying tissues. Necrosis rate (NR, cm(3)/s) was used to reflect the ablation efficiency, which was the tissue volume of occurring coagulative necrosis per 1 s HIFU exposure. NR was improved in the experimental group (0.0570 +/- 0.0433 vs 0.0120 +/- 0.0122, P = 0.0002). Pathological studies confirmed that there were no residual intact targets within the exposed volume. These findings suggested that the introduction of the microbubble agent enhanced HIFU liver destruction. (c) 2005 Elsevier B.V. All rights reserved.