Nanodroplet-mediated histotripsy. (A) Perfluorocarbon nanodroplets significantly reduce the histotripsy intrinsic threshold, allowing for (B) selective generation of cavitation only in regions containing the targeted nanodroplets. Reprinted from Theranostics, vol. 3, Vlaisavljevich et al, Nanodroplet-mediated histotripsy for image-guided targeted ultrasound cell ablation, p. 851, doi:10.7150/thno.6717.(2013).