Optical observation of contrast agent destruction

Fragmentation of an ultrasound contrast agent on the time scale of microsec onds provides opportunities for the advancement of microvascular detection, blood flow velocity estimation, and targeted drug delivery. Images capture d by high-speed imaging systems show destruction of a microbubble during co mpression. Peak wall velocity of -700 m/s and peak acceleration of 1.2 x 10 (12) m/s(2) is observed for insonation with a peak pressure of -1.1 MPa and a center frequency of 2.4 MHz. Theoretical calculations of wall velocity a nd acceleration using a modified Rayleigh-Plesset model predict a peak nega tive wall velocity of -680 m/s and peak acceleration of 2 x 10(12) m/s(2). (C) 2000 American Institute of Physics. [S0003-6951(00)03030-8].