Volumetric ultrasound imaging of blood flow with microbubbles enables a more complete visualization of the microvasculature. Sparse arrays are ideal candidates to perform volumetric imaging at reduced manufacturing complexity and cable count. However, due to the small number of transducer elements, sparse arrays often come with high clutter levels, especially when wide beams are transmitted to increase the frame rate. In this study, we demonstrate with a prototype sparse array probe and a diverging wave transmission strategy, that a uniform transmission field can be achieved. With the implementation of a spatial coherence beamformer, the background clutter signal can be effectively suppressed, leading to a signal to background ratio improvement of 25 dB. With this approach, we demonstrate the volumetric visualization of single microbubbles in a tissue-mimicking phantom as well as vasculature mapping in a live chicken embryo chorioallantoic membrane.

中文翻译：

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使用稀疏阵列和空间相干波束成形对微气泡进行高帧率体积成像。

带有微泡的血流体积超声成像能够更完整地显示微血管系统。稀疏阵列是在降低制造复杂性和电缆数量的情况下执行体积成像的理想选择。然而，由于换能器元件的数量很少，稀疏阵列通常会带来高杂波水平，尤其是在传输宽波束以提高帧速率时。在这项研究中，我们使用原型稀疏阵列探头和发散波传输策略证明可以实现均匀的传输场。通过空间相干波束形成器的实施，可以有效抑制背景杂波信号，使信噪比提高25 dB。通过这种方法，