Observations of translation and jetting of ultrasound-activated microbubbles in mesenteric microvessels.
High-speed photomicrography was used to study the translational dynamics of single microbubbles in microvessels of ex vivo rat mesenteries. The microbubbles were insonated by a single 2 μs ultrasound pulse with a center frequency of 1 MHz and peak negative pressures spanning the range of 0.8-4 MPa. The microvessel diameters ranged from 10-80 μm. The high-speed image sequences show evidence of ultrasound-activated microbubble translation away from the nearest vessel wall; no microbubble showed a net translation toward the nearest vessel wall. Microbubble maximum translation displacements exceeded 20 μm. Microjets with the direction of the jets identifiable were also observed; all microjets appear to have been directed away from the nearest vessel wall. These observations appear to be characteristic of a strong coupling between ultrasound-driven microbubbles and compliant microvessels. Although limited to mesenteric tissues, these observations provide an important step in understanding the physical interactions between microbubbles and microvessels.
Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA, USA.
Hong
H
Chen
Andrew A
AA
Brayman
Wayne
W
Kreider
Michael R
MR
Bailey
Thomas J
TJ
Matula
D000818:Animals; D008643:Mesentery / Q000098:blood supply* / Q000166:cytology*; D045423:Microbubbles; D018715:Microscopy, Video / Q000379:methods*; D055806:Microvessels / Q000166:cytology*; D009038:Motion; D051381:Rats; D011916:Rats, Inbred F344; D013010:Sonication