The relation between cavitation and platelet aggregation during exposure to high-intensity focused ultrasound.
Our previous study showed that high-intensity focused ultrasound (HIFU) is capable of producing "primary acoustic hemostasis" in the form of ultrasound (US)-induced platelet activation, aggregation and adhesion to a collagen-coated surface. In the current study, 1.1 MHz continuous-wave HIFU was used to investigate the role of cavitation as a mechanism for platelet aggregation in samples of platelet-rich plasma. A 5 MHz passive cavitation detector was used to monitor cavitation activity and laser aggregometry was used to measure platelet aggregation. Using spatial average intensities from 0 to 3350 W/cm2, the effects of HIFU-induced cavitation on platelet aggregation were investigated by enhancing cavitation activity through use of US contrast agents and by limiting cavitation activity through use of an overpressure system. Our results show that increased cavitation activity lowers the intensity threshold to produce platelet aggregation and decreased cavitation activity in the overpressure system raises the intensity threshold for platelet aggregation.
Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, USA. poliachi@u.washington.edu
Sandra L
SL
Poliachik
Wayne L
WL
Chandler
Ryan J
RJ
Ollos
Michael R
MR
Bailey
Lawrence A
LA
Crum
D000418:Albumins; D001777:Blood Coagulation / Q000502:physiology; D003287:Contrast Media; D006801:Humans; D010974:Platelet Aggregation / Q000502:physiology*; D011312:Pressure; D014463:Ultrasonography / Q000379:methods*
D000418:Albumins; C060687:Albunex; D003287:Contrast Media