Zhu Yiying I, Miller Douglas L, Dou Chunyan, Kripfgans Oliver D
Biomedical Engineering, University of Michigan, Ann Arbor, MI.
Department of Radiology, University of Michigan Medical Center, Ann Arbor, MI.
AIP Conf Proc. 2017;1816(1). doi: 10.1063/1.4976594. Epub 2017 Mar 1.
Intermittent high intensity ultrasound pulses with circulating contrast agent microbubbles can induce scattered microlesions of potential value for myocardial reduction therapy. This paper presents an setup imitating the treatment for monitoring development. A preclinical imaging system with a single element transducer, synchronization and receive-only imaging transducer array has been implemented on a research platform. Contrast agent microbubbles pumped in a dialysis tubing setup were exposed to high intensity focused ultrasound at 1.0/3.5 MHz center frequencies. Polystyrene spheres were employed as linear scatterers compared to contrast agents for system transfer function equalization. A cavitation mapping technique was employed to spatially locate and depict microbubble activity during treatment. For high acoustic pressure amplitudes a 5 dB difference between contrast agent and solid spheres was observed and spatially mapped. The in-plane resolution was 4.5 mm for axial and 1.5 mm laterally. In the future, this cavitation detection scheme will be applied to monitor microlesioning in real-time.
携带循环造影剂微泡的间歇性高强度超声脉冲可诱导产生具有心肌消融治疗潜在价值的散在微损伤。本文介绍了一种模拟该治疗过程以监测其发展的装置。在一个研究平台上实现了一个具有单元素换能器、同步和仅接收成像换能器阵列的临床前成像系统。在透析管装置中泵入的造影剂微泡，在中心频率为1.0/3.5 MHz的高强度聚焦超声作用下接受照射。与造影剂相比，聚苯乙烯球体被用作线性散射体，以实现系统传递函数均衡。采用了一种空化映射技术来在空间上定位和描绘治疗过程中的微泡活动。对于高声压幅值，观察到造影剂与实心球体之间存在5 dB的差异，并进行了空间映射。轴向平面内分辨率为4.5 mm，横向为1.5 mm。未来，这种空化检测方案将被应用于实时监测微损伤。
