We studied the interaction of ultrasound contrast agent bubbles coated with a layer of lipids, driven by 0.5 MHz ultrasound. High-speed photography on the submicrosecond timescale reveals that some bubbles bounce off each other, while others show very fast coalescence during bubble expansion. This fast coalescence cannot be explained by dissipation-limited film drainage rates. We conclude that the lipid shell ruptures upon expansion, exposing clean free bubble interfaces that support plug flow profiles in the film and inertia-limited drainage whose time scales match those of the observed coalescence. (E-mail: M.postema@erasmusmc.nl)

Film drainage, high-speed photography, Microbubble coalescence, Ultrasound contrast agent
dx.doi.org/10.1016/j.ultrasmedbio.2004.08.008, hdl.handle.net/1765/64916
Ultrasound in Medicine & Biology
Department of Cardiology

Postema, M, Marmottant, P, Lancée, C.T, Hilgenfeldt, S, & de Jong, N. (2004). Ultrasound-induced microbubble coalescence. Ultrasound in Medicine & Biology, 30(10), 1337–1344. doi:10.1016/j.ultrasmedbio.2004.08.008