Fast and Selective Super-Resolution Ultrasound In Vivo With Acoustically Activated Nanodroplets.
Fast and Selective Super-Resolution Ultrasound In Vivo With Acoustically Activated Nanodroplets.
复制标题
使用声学激活纳米液滴进行快速选择性体内超分辨率超声检查。
DOI：
10.1109/tmi.2022.3223554
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发表时间：
2023
影响因子：
10.6
通讯作者：
Riemer K
中科院分区：
文献类型：
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作者：
Riemer K
微循环的灌注对于组织的发育、维持和病理学至关重要。因此，其高时空分辨率的测量很有价值，但在深层组织中仍然是一个挑战。超声定位显微镜（ULM）提供非常高的时空分辨率，但使用微泡需要低造影剂浓度、较长的采集时间，并且对微泡的空间和时间分布几乎无法控制。本研究首次展示了声波稀疏激活定位显微镜 (AWSALM) 和快速 AWSALM 用于体内超分辨率超声成像，提供按需对比和血管选择性。使用了三种不同配方的声激活造影剂。我们证明了它们在超声机械指数方面的使用完全在建议的安全限度内，从而能够在非常高的药剂浓度下实现快速按需稀疏激活和破坏。我们制作了兔肾脉管系统的超定位图，采集时间在 5.5 秒至 0.25 秒之间，空间分辨率提高了 4 倍。我们展示了 AWSALM 在可视化特定血管分支和下游微脉管系统方面的独特选择性，并展示了收缩期（0.25 秒）和舒张期（0.25 秒）的超局部肾脏结构，快速 AWSALM 的性能优于基于微泡的 ULM。总之，我们证明了使用超声和声激活纳米液滴造影剂以亚波长分辨率对体内微血管动力学进行快速选择性成像的可行性。
Perfusion by the microcirculation is key to the development, maintenance and pathology of tissue. Its measurement with high spatiotemporal resolution is consequently valuable but remains a challenge in deep tissue. Ultrasound Localization Microscopy (ULM) provides very high spatiotemporal resolution but the use of microbubbles requires low contrast agent concentrations, a long acquisition time, and gives little control over the spatial and temporal distribution of the microbubbles. The present study is the first to demonstrate Acoustic Wave Sparsely-Activated Localization Microscopy (AWSALM) and fast-AWSALM for in vivo super-resolution ultrasound imaging, offering contrast on demand and vascular selectivity. Three different formulations of acoustically activatable contrast agents were used. We demonstrate their use with ultrasound mechanical indices well within recommended safety limits to enable fast on-demand sparse activation and destruction at very high agent concentrations. We produce super-localization maps of the rabbit renal vasculature with acquisition times between 5.5 s and 0.25 s, and a 4-fold improvement in spatial resolution. We present the unique selectivity of AWSALM in visualizing specific vascular branches and downstream microvasculature, and we show super-localized kidney structures in systole (0.25 s) and diastole (0.25 s) with fast-AWSALM outperforming microbubble based ULM. In conclusion, we demonstrate the feasibility of fast and selective imaging of microvascular dynamics in vivo with subwavelength resolution using ultrasound and acoustically activatable nanodroplet contrast agents.