On the acoustic response of microbubbles in arteriole sized vessels

Microbubbles are used to improve ultrasound imaging of the vascular bed. Optical microscopy has shown microbubbles in different size tubes which have different responses to ultrasound. The acoustic scatter associated with such differences has not been previously measured. Echoes from two types of microbubbles, in narrow tubes, were collected at incident ultrasound parameters relevant to diagnostic imaging. Microbubbles were found to have increased second harmonic signatures in 50 mu m diameter tubes compared to 200 mu m. There was decreased survival of lipid microbubbles in the smaller tube. Understanding scatter mechanisms in narrow tubes is useful for signal processing optimisation for imaging applications. VC 2011 American Institute of Physics. [doi: 10.1063/1.3657519]