Postema Michiel, van Wamel Annemieke, Lancée Charles T, de Jong Nico
Department of Experimental Echocardiography, Thoraxcentre, Erasmus MC, Rotterdam, The Netherlands.
Ultrasound Med Biol. 2004 Jun;30(6):827-40. doi: 10.1016/j.ultrasmedbio.2004.02.010.
When encapsulated microbubbles are subjected to high-amplitude ultrasound, the following phenomena have been reported: oscillation, translation, coalescence, fragmentation, sonic cracking and jetting. In this paper, we explain these phenomena, based on theories that were validated for relatively big, free (not encapsulated) gas bubbles. These theories are compared with high-speed optical observations of insonified contrast agent microbubbles. Furthermore, the potential clinical applications of the bubble-ultrasound interaction are explored. We conclude that most of the results obtained are consistent with free gas bubble theory. Similar to cavitation theory, the number of fragments after bubble fission is in agreement with the dominant spherical harmonic oscillation mode. Remarkable are our observations of jetting through contrast agent microbubbles. The pressure at the tip of a jet is high enough to penetrate any human cell. Hence, liquid jets may act as remote-controlled microsyringes, delivering a drug to a region-of-interest. Encapsulated microbubbles have (potential) clinical applications in both diagnostics and therapeutics.
当封装的微泡受到高振幅超声作用时，已报道出现以下现象：振荡、平移、合并、破碎、声裂解和喷射。在本文中，我们基于针对相对较大的自由（未封装）气泡验证的理论来解释这些现象。将这些理论与被超声照射的造影剂微泡的高速光学观测结果进行比较。此外，还探讨了气泡 - 超声相互作用的潜在临床应用。我们得出的结论是，获得的大多数结果与自由气泡理论一致。与空化理论类似，气泡裂变后的碎片数量与占主导的球谐振荡模式相符。我们对通过造影剂微泡的喷射现象的观测值得关注。射流尖端的压力足以穿透任何人体细胞。因此，液体射流可充当遥控微注射器，将药物输送到感兴趣的区域。封装的微泡在诊断和治疗方面均具有（潜在的）临床应用。
