Joint Department of Biomedical Engineering, University of North Carolina-North Carolina State University, Chapel Hill, NC, USA.
Ultrasound Med Biol. 2012 Apr;38(4):651-60. doi: 10.1016/j.ultrasmedbio.2011.12.005. Epub 2012 Feb 15.
For more than a decade, the application of acoustic radiation force (ARF) has been proposed as a mechanism to increase ultrasonic molecular imaging (MI) sensitivity in vivo. Presented herein is the first noninvasive in vivo validation of ARF-enhanced MI with an unmodified clinical system. First, an in vitro optical-acoustical setup was used to optimize system parameters and ensure sufficient microbubble translation when exposed to ARF. 3-D ARF-enhanced MI was then performed on 7 rat fibrosarcoma tumors using microbubbles targeted to α(v)β₃ and nontargeted microbubbles. Low-amplitude (<25 kPa) 3-D ARF pulse sequences were tested and compared with passive targeting studies in the same animal. Our results demonstrate that a 78% increase in image intensity from targeted microbubbles can be achieved when using ARF relative to the passive targeting studies. Furthermore, ARF did not significantly increase image contrast when applied to nontargeted agents, suggesting that ARF did not increase nonspecific adhesion.
十多年来，声辐射力（ARF）的应用一直被提议作为一种提高活体超声分子成像（MI）灵敏度的机制。本文首次在未经修改的临床系统中对 ARF 增强 MI 进行了非侵入性的体内验证。首先，使用体外光声设置优化了系统参数，并确保微泡在暴露于 ARF 时能够充分转移。然后，使用针对 α(v)β₃的靶向微泡和非靶向微泡对 7 只大鼠纤维肉瘤肿瘤进行了 3-D ARF 增强 MI。测试了低幅度（<25 kPa）的 3-D ARF 脉冲序列，并与同一动物中的被动靶向研究进行了比较。结果表明，与被动靶向研究相比，使用 ARF 可以使靶向微泡的图像强度增加 78%。此外，当应用于非靶向试剂时，ARF 并没有显著增加图像对比度，这表明 ARF 并没有增加非特异性黏附。
