Chen Peiran, Pollet Andreas M A O, Turco Simona, de Vargas Miguel, Te Winkel Lisa, van Hoeve Wim, den Toonder Jaap M J, Wijkstra Hessel, Mischi Massimo
Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, 5612 AP, The Netherlands.
Department of Mechanical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, 5612 AE, The Netherlands.
J Acoust Soc Am. 2025 Apr 1;157(4):2687-2696. doi: 10.1121/10.0036371.
Contrast-enhanced ultrasound (CEUS) super-localization imaging has shown promise for the assessment of microvascular networks by localizing and tracking microbubbles. The size of the available microbubbles for clinical use is polydisperse, but size-tailorable monodisperse microbubbles are now being developed that present a narrow size distribution. Therefore, proper frequency and pressure tuning have the potential to improve the signal-to-noise ratio and resolution of CEUS acquisitions, which can be expected to increase the performance of CEUS super-localization imaging. In this work, the impact of monodisperse microbubble size on CEUS imaging quality and the efficacy of super-localization imaging was investigated by jointly tuning different frequencies and pressures for different monodisperse microbubble size when performing in vitro CEUS imaging of microbubbles flowing through a dedicated sugar-printed dual-bifurcation microvasculature phantom. The obtained CEUS acquisitions were then post-processed to generate a super-localization output using the Gaussian-centroid localization approach. Four metrics, including generalized contrast-to-noise ratio, full-width half-maximum, number of localization events, and localization F1-score, were employed to quantify the CEUS imaging quality and super-localization performance. In general, jointly optimizing the transmit frequency and pressure for monodisperse microbubbles with smaller size leads to improved CEUS imaging and better super-localization performance. Yet, the weaker backscatter of smaller microbubbles must also be considered.
超声造影（CEUS）超定位成像已显示出通过定位和跟踪微泡来评估微血管网络的前景。临床可用的微泡大小呈多分散性，但目前正在开发尺寸可定制的单分散微泡，其尺寸分布较窄。因此，适当的频率和压力调谐有可能提高CEUS采集的信噪比和分辨率，这有望提高CEUS超定位成像的性能。在这项工作中，通过在对流经专用糖印双分支微血管模型的微泡进行体外CEUS成像时，针对不同单分散微泡大小联合调谐不同频率和压力，研究了单分散微泡大小对CEUS成像质量和超定位成像效果的影响。然后对获得的CEUS采集数据进行后处理，使用高斯质心定位方法生成超定位输出。采用广义对比度噪声比、半高宽、定位事件数量和定位F1分数这四个指标来量化CEUS成像质量和超定位性能。一般来说，对较小尺寸的单分散微泡联合优化发射频率和压力可改善CEUS成像并获得更好的超定位性能。然而，还必须考虑较小微泡的反向散射较弱这一因素。
