Sheeran Paul S, Rojas Juan D, Puett Connor, Hjelmquist Jordan, Arena Christopher B, Dayton Paul A
Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA.
Department of Biomedical Engineering, North Carolina State University, Raleigh, North Carolina, USA.
Ultrasound Med Biol. 2015 Mar;41(3):814-31. doi: 10.1016/j.ultrasmedbio.2014.10.020. Epub 2015 Jan 22.
Many studies have explored phase-change contrast agents (PCCAs) that can be vaporized by an ultrasonic pulse to form microbubbles for ultrasound imaging and therapy. However, few investigations have been published on the utility and characteristics of PCCAs as contrast agents in vivo. In this study, we examine the properties of low-boiling-point nanoscale PCCAs evaluated in vivo and compare data with those for conventional microbubbles with respect to contrast generation and circulation properties. To do this, we develop a custom pulse sequence to vaporize and image PCCAs using the Verasonics research platform and a clinical array transducer. Results indicate that droplets can produce contrast enhancement similar to that of microbubbles (7.29 to 18.24 dB over baseline, depending on formulation) and can be designed to circulate for as much as 3.3 times longer than microbubbles. This study also reports for the first time the ability to capture contrast washout kinetics of the target organ as a measure of vascular perfusion.
许多研究都探索了相变造影剂（PCCA），这种造影剂可被超声脉冲汽化形成微泡，用于超声成像和治疗。然而，关于PCCA作为体内造影剂的效用和特性，发表的研究很少。在本研究中，我们检测了在体内评估的低沸点纳米级PCCA的特性，并就造影剂产生和循环特性，将数据与传统微泡的数据进行比较。为此，我们开发了一种定制脉冲序列，使用Verasonics研究平台和临床阵列换能器对PCCA进行汽化和成像。结果表明，液滴可产生与微泡类似的造影增强效果（比基线高出7.29至18.24分贝，具体取决于配方），并且其设计循环时间可比微泡长3.3倍。本研究还首次报告了能够捕捉靶器官的造影剂洗脱动力学，以此作为血管灌注的一种测量方法。
