Ultrasound-induced encapsulated microbubble phenomena
Résumé
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 to 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 harmonical oscillation mode. Remarkable are our observations of jetting through contrast agent microbubbles. This 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.
Origine | Fichiers produits par l'(les) auteur(s) |
---|