Contrast agents are routinely used in ultrasound examinations. Nonlinear ultrasound imaging techniques have been developed over decades to enhance the contrast between the tissue and the blood pool after the injection of ultrasound contrast agents (UCAs). In this study, we introduce a new contrast pulse sequence, CPS4. The CPS4 combines pulse inversion (PI), subharmonic (SH), and ultraharmonic (UH) techniques to remove propagation distortion while capturing the unique SH and UH responses from UCAs. The novel CPS4 and conventional PI, SH, and UH techniques were used to detect the presence of a research-grade, thick-shell, polymer microbubble in a tissue-mimicking flow phantom. The contrast-to-tissue ratios (CTRs) obtained from the applications of all techniques were compared. The results show that the highest CTR of approximately 16 dB was obtained using CPS4, which was superior to the individual reference techniques: PI, SH, and UH techniques, in all scenarios considered in this study.

中文翻译：

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新型的聚合物壳微泡对比度脉冲序列的发展

造影剂通常用于超声检查。非线性超声成像技术已经开发了数十年，以增强注射超声造影剂（UCA）后组织与血池之间的对比度。在这项研究中，我们介绍了一种新的对比脉冲序列CPS4。CPS4结合了脉冲反转（PI），次谐波（SH）和超谐波（UH）技术，以消除传播失真，同时捕获来自UCA的独特SH和UH响应。新颖的CPS4和常规的PI，SH和UH技术用于检测模仿组织的体模中研究级厚壳聚合物微泡的存在。比较了从所有技术的应用中获得的对比组织比率（CTR）。