A comparison of the hemolytic potential of Optison and Albunex in whole human blood in vitro: acoustic pressure, ultrasound frequency, donor and passive cavitation detection considerations.

This project tested the hypothesis that a "second-generation" ultrasound (US) contrast agent (Optison), offering extended echogenicity over that of its "first-generation" predecessor (Albunex), would have the greater potential for sonolysis of human erythrocytes in vitro. Whole human blood, obtained from apparently healthy donors, was anticoagulated and subsequently exposed in vitro to US in the presence of one of each or neither of the two US contrast agents. The US exposures were for 30 s and involved frequency (1.0, 2.2 and 3.4 MHz) and amplitude (approximately 2.8 to 0.38 MPa P(-)) regimens; pulse duration (200 micros) and interpulse interval (20 ms) were held constant. The data supported the hypothesis, with an overall ratio of approximately 2.5 for relative extent of background-corrected US-induced hemolysis of the Optison/Albunex regimens. Passive cavitation detection analyses corroborated the results obtained with hemolysis.