Two‐Dimensional Real‐time Ultrasound Technique to Control Lesion Size during HIFU Therapy

The lack of accurate and low‐cost techniques for real‐time monitoring and feedback during ablative therapies such as HIFU has limited its widespread clinical adoption. A good ultrasound solution would enable a much more widespread usage of HIFU therapy. An acoustic radiation force (ARF) based technique for controlling the lesion size and its placement during HIFU therapy has been developed. A series of experiments were performed in excised bovine liver tissue to evaluate the proposed technique. The change in the ARF induced displacements during therapy at each spatial location was quantified by a unitless parameter, normalized displacement difference (NDD), defined as the difference between normalized displacement at the therapy endpoint and a reference determined from the data. The 2‐D displacement map (normalized to the value before therapy commenced) illustrated that displacements initially increased due to the temperature rise, reached a maximum, and then decreased with continuing therapy. Strong corr...