Larsson Malin, Larsson Matilda, Oddo Letizia, Margheritelli Silvia, Paradossi Gaio, Nowak Jacek, Brodin Lars-Åke, Caidahl Kenneth, Bjällmark Anna
Department of Medical Engineering, School of Technology and Health, KTH Royal Institute of Technology, Alfred Nobels Allé 10, 141 52, Huddinge, Stockholm, Sweden.
Cardiovasc Ultrasound. 2013 Aug 29;11:33. doi: 10.1186/1476-7120-11-33.
A multimodal polymer-shelled contrast agent (CA) with target specific potential was recently developed and tested for its acoustic properties in a single element transducer setup. Since the developed polymeric CA has different chemical composition than the commercially available CAs, there is an interest to study its acoustic response when using clinical ultrasound systems. The aim of this study was therefore to investigate the acoustic response by studying the visualization capability and shadowing effect of three polymer-shelled CAs when using optimized sequences for contrast imaging.
The acoustic response of three types of the multimodal CA was evaluated in a tissue mimicking flow phantom setup by measuring contrast to tissue ratio (CTR) and acoustic shadowing using five image sequences optimized for contrast imaging. The measurements were performed over a mechanical index (MI) range of 0.2-1.2 at three CA concentrations (106, 105, 104 microbubbles/ml).
The CTR-values were found to vary with the applied contrast sequence, MI and CA. The highest CTR-values were obtained when a contrast sequence optimized for higher MI imaging was used. At a CA concentration of 106 microbubbles/ml, acoustic shadowing was observed for all contrast sequences and CAs.
The CAs showed the potential to enhance ultrasound images generated by available contrast sequences. A CA concentration of 106 MBs/ml implies a non-linear relation between MB concentration and image intensity.
最近开发了一种具有靶向特异性潜力的多模态聚合物壳造影剂（CA），并在单元素换能器设置中测试了其声学特性。由于所开发的聚合物CA与市售CA具有不同的化学成分，因此有必要研究其在使用临床超声系统时的声学响应。因此，本研究的目的是通过使用优化的对比成像序列研究三种聚合物壳CA的可视化能力和阴影效应，来研究其声学响应。
在模拟组织的血流模型设置中，通过使用五个针对对比成像优化的图像序列测量对比组织比（CTR）和声学阴影，评估了三种多模态CA的声学响应。在三种CA浓度（106、105、104微泡/毫升）下，在0.2-1.2的机械指数（MI）范围内进行测量。
发现CTR值随所应用的对比序列、MI和CA而变化。当使用针对更高MI成像优化的对比序列时，可获得最高的CTR值。在CA浓度为106微泡/毫升时，所有对比序列和CA均观察到声学阴影。
这些CA显示出增强现有对比序列生成的超声图像的潜力。106 MBs/ml的CA浓度意味着微泡浓度与图像强度之间存在非线性关系。
