IEEE Trans Ultrason Ferroelectr Freq Control. 2018 Dec;65(12):2212-2221. doi: 10.1109/TUFFC.2018.2856756. Epub 2018 Jul 17.
Contrast echocardiography (CE) ultrasound with microbubble contrast agents has significantly advanced our capability for assessment of cardiac function, including myocardium perfusion quantification. However, in standard CE techniques obtained with line by line scanning, the frame rate and image quality are limited. Recent research has shown significant frame-rate improvement in noncontrast cardiac imaging. In this work, we present and initially evaluate, both in vitro and in vivo, a high-frame-rate (HFR) CE imaging system using diverging waves and pulse inversion sequence. An imaging frame rate of 5500 frames/s before and 250 frames/s after compounding is achieved. A destruction-replenishment sequence has also been developed. The developed HFR CE is compared with standard CE in vitro on a phantom and then in vivo on a sheep heart. The image signal-to-noise ratio and contrast between the myocardium and the chamber are evaluated. The results show up to 13.4-dB improvement in contrast for HFR CE over standard CE when compared at the same display frame rate even when the average spatial acoustic pressure in HFR CE is 36% lower than the standard CE. It is also found that when coherent compounding is used, the HFR CE image intensity can be significantly modulated by the flow motion in the chamber.
对比超声心动图（CE）与微泡造影剂显著提高了我们评估心脏功能的能力，包括心肌灌注定量。然而，在逐行扫描的标准 CE 技术中，帧率和图像质量受到限制。最近的研究表明，非对比心脏成像的帧率有了显著提高。在这项工作中，我们展示并初步评估了一种使用发散波和脉冲反转序列的高帧率（HFR）CE 成像系统，在复合前可达到 5500 帧/秒，复合后可达到 250 帧/秒。还开发了破坏-补充序列。在体模上对开发的 HFR CE 与标准 CE 进行了体外比较，然后在绵羊心脏上进行了体内比较。评估了图像信噪比和心肌与心室之间的对比度。结果表明，与标准 CE 相比，即使在 HFR CE 的平均空间声压比标准 CE 低 36%的情况下，当在相同的显示帧率下进行比较时，HFR CE 的对比度提高了高达 13.4dB。还发现，当使用相干复合时，HFR CE 图像强度可以被室内的流动运动显著调制。
