Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA, USA.
Ultrasound Med Biol. 2011 Dec;37(12):2139-48. doi: 10.1016/j.ultrasmedbio.2011.09.013. Epub 2011 Oct 27.
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.
高速显微摄影用于研究单个微泡在离体大鼠肠系膜微血管中的平移动力学。微泡通过单个 2 μs 超声脉冲刺激，中心频率为 1 MHz，峰值负压范围为 0.8-4 MPa。微血管直径为 10-80 μm。高速图像序列显示了超声激活微泡远离最近血管壁的平移的证据；没有微泡显示出向最近血管壁的净平移。微泡的最大平移位移超过 20 μm。还观察到了具有可识别喷射方向的微射流；所有微射流似乎都指向远离最近血管壁的方向。这些观察结果似乎是超声驱动微泡与顺应性微血管之间强耦合的特征。尽管这些观察结果仅限于肠系膜组织，但它们为理解微泡和微血管之间的物理相互作用提供了重要的一步。
