Persistence of Albunex (ALB) Ultrasound Contrast Agent – Invitro Study of the Effects of Pressure and Acoustic Power on Particle-Size, and the Duration of Contrast and Doppler Enhancement

Abstract

LV contrast intensity after intravenous ALB
\ninjection varies with the cardiac cycle, raising
\nquestions about the pressure related stability
\nof the particle. We explored pressure stability
\nand the influence of acoustic power on ALB
\neffect in an in-vitro pulsatile model at receiving chamber (RC) pressures between 10-160 mmHg.
\nUltrasound imaging was performed at 5MHz along
\nwith 3.5MHz color Doppler at maximal and minimal
\nlevels of acoustic power output on a VingMed CFM
\nscanner. We also studied the effects of static
\nRC pressure on particle size and survival using
\na new phase shift laser Doppler device (Dantec).
\nAn inverse relationship existed between RC mean
\npressure and the duration of both echo and Doppler enhancement (r-0.95 and r-0.94, respectively).
\nAt 40-80 mmHg RC pressures, contrast
\npersistence determinations were shorter at the
\nhigher compared to the lower acoustic power output (p- <0.05). On laser Doppler study, particle
\nsize decreased as RC pressure increased prior to
\nparticle disruption. Higher RC pressures com·
\npress the ALB micro particle and decrease its
\nhalf-life. Increased acoustic output may also
\nshorten ALB effect.