Kripfgans O D, Fowlkes J B, Miller D L, Eldevik O P, Carson P L
University of Michigan Health Systems, Department of Radiology, Ann Arbor, MI, USA.
Ultrasound Med Biol. 2000 Sep;26(7):1177-89. doi: 10.1016/s0301-5629(00)00262-3.
A phase shift droplet emulsion is introduced as an aid to unusual ultrasound (US) applications. The transpulmonary droplet emulsion (90% < 6 microm diameter) is made by mixing saline, bovine albumin and dodecafluoropentane. It has been observed that an acoustic pressure threshold exists, above which the droplets vaporize into bubbles approximately 25 times the original diameter. For frequencies between 1.5 and 8 MHz, the threshold decreases from 4.5 to 0.75 MPa peak rarefactional pressure. This paper presents preliminary results for droplet preparation and their evaporation as a function of applied acoustic pressure and frequency, as well as simulations of the lifetime of these gas bubbles based on gas diffusion. In vivo experiments were simulated by the evaporation of droplets in blood flowing under attenuating material. We propose that this agent might be useful for tissue occlusion in cancer treatment, as well as for phase aberration corrections in acoustic imaging.
引入了一种相移液滴乳液，以辅助进行特殊的超声（US）应用。经肺液滴乳液（直径90%<6微米）是通过将盐水、牛白蛋白和十二氟戊烷混合制成的。据观察，存在一个声压阈值，高于该阈值时，液滴会汽化成直径约为原始直径25倍的气泡。对于1.5至8兆赫兹之间的频率，该阈值从4.5兆帕的峰值稀疏压力降至0.75兆帕。本文给出了液滴制备及其蒸发随施加声压和频率变化的初步结果，以及基于气体扩散对这些气泡寿命的模拟。通过在衰减材料下流动的血液中液滴的蒸发来模拟体内实验。我们认为这种试剂可能对癌症治疗中的组织闭塞以及声学成像中的相位像差校正有用。
