title: In vivo characterization of ultrasound contrast agents: microbubble spectroscopy in a chicken embryo.
abstract: The dynamics of coated microbubbles was studied in an in vivo model. Biotinylated lipid-coated microbubbles were prepared in-house and were injected into a chick embryo chorioallantoic membrane (CAM) model on the fifth day of incubation. The microbubbles, ranging between 1.0 and 3.5 μm in diameter, were insonified in the frequency range of 4-7 MHz. Two amplitudes of acoustic pressure were applied: 300 kPa and 400 kPa. The fundamental and subharmonic responses were recorded optically with an ultra-fast camera (Brandaris 128) at 20 million frames per second. A subharmonic response was observed for 44% of the studied bubbles. From the data the frequency of the maximum fundamental and subharmonic response was derived for each individual bubble and resulted in the resonance curves of the microbubbles. All the bubbles showed shell (strain) hardening behavior for a higher acoustic pressure. We conclude that the subharmonic oscillations observed in this study belonged to the transmit at resonance (TR) regime.
authors: Biomedical Engineering, Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands. t.faez@erasmusmc.nl
authors: Telli
authors: T
authors: Faez
authors: Ilya
authors: I
authors: Skachkov
authors: Michel
authors: M
authors: Versluis
authors: Klazina
authors: K
authors: Kooiman
authors: Nico
authors: N
authors: de Jong
mesh_terms: D000162:Acoustics / Q000295:instrumentation; D000818:Animals; D002642:Chick Embryo / Q000000981:diagnostic imaging*; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003287:Contrast Media / Q000737:chemistry*; D004867:Equipment Design; D045423:Microbubbles; D023421:Models, Animal; D013010:Sonication / Q000295:instrumentation; D014463:Ultrasonography
chemical_list: D020099:Coated Materials, Biocompatible; D003287:Contrast Media