Nonlinear acoustical response of coated microbubbles in diagnostic ultrasound

Microbubbles coated with a thin biodegradable polymer shell are used in SHU 563 A, a new kind of ultrasound contrast medium. These particles are durable linear scatterers for prolonged times at low acoustic pressure amplitudes. They will immediately rupture at higher amplitudes within the range of diagnostic ultrasound causing a transient nonlinear response termed “Acoustically Stimulated Acoustic Emission”. Characteristics of this effect and some potential applications in novel and extraordinary sensitive conventional and Harmonic Imaging modes are discussed