Mayer S, Grayburn P A
Department of Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75235-9047, USA.
Prog Cardiovasc Dis. 2001 Jul-Aug;44(1):33-44. doi: 10.1053/pcad.2001.26438.
The assessment of perfusion by myocardial contrast echocardiography has evolved from the early contrast agents, including agitated saline solutions and hydrogen peroxide, to the current second-generation contrast agents. Unlike the first-generation contrast agents, which are composed of air, the newer, second-generation agents contain gases with a higher molecular weight and less solubility and diffusivity, improving microbubble persistence. The newer contrast agents are capable of transpulmonary passage and opacification of the left-heart chambers and the myocardial microcirculation after intravenous administration. Also, innovative imaging techniques using harmonics and triggered imaging have minimized tissue signal and improved signal-to-noise ratio, making the assessment of myocardial perfusion possible. Currently, microbubbles are being designed for specific research or clinical use by exploiting certain characteristics of the microbubble such as the shell, surface characteristics, and/or gas content. Some novel applications of microbubble technology include tissue-targeted gene therapy, drug delivery, ultrasound-enhanced thrombolysis, and the assessment of endothelial function and integrity. This review focuses on the composition, physical properties, and acoustic characteristics of the currently available myocardial contrast agents and those under clinical investigation. In addition, the clinical trials involving these agents will also be discussed.
心肌对比超声心动图对灌注的评估已从早期的造影剂（包括搅动生理盐水溶液和过氧化氢）发展到目前的第二代造影剂。与由空气组成的第一代造影剂不同，更新的第二代造影剂含有分子量更高、溶解度和扩散性更低的气体，从而改善了微泡的持久性。新型造影剂能够在静脉给药后经肺通过并使左心腔和心肌微循环显影。此外，使用谐波和触发成像的创新成像技术已将组织信号降至最低并提高了信噪比，使得心肌灌注评估成为可能。目前，通过利用微泡的某些特性（如外壳、表面特性和/或气体含量），正在设计用于特定研究或临床用途的微泡。微泡技术的一些新应用包括组织靶向基因治疗、药物递送、超声增强溶栓以及内皮功能和完整性评估。本综述重点关注目前可用的心肌造影剂以及正在进行临床研究的造影剂的组成、物理性质和声学特性。此外，还将讨论涉及这些造影剂的临床试验。
