3Deng CX, Lizzi FL. A review of physical phenomena associat ed with ultrasonic contrast agents and illustrative clinical applications[J]. Ultrasound Med Biol, 2002, 28(3): 277-286.
4Pisani E, Tsapis N, Paris J, et al. Polymeric nano/microcapsules of liquid perfluorocarbons for ultrasonic imaging: physical characterization[J]. Langmuir, 2006,22(9) :4397-4402.
5Kooimana K, Bohmerb M, Emmer M,et al. Oil-filled polymer microcapsules for ultrasound-mediated delivery of lipophilic drugs [J]. J of Control Release, 2009, 133(2): 109-118.