Tan Qingyuan, Riemer Kai, Hansen-Shearer Joseph, Yan Jipeng, Toulemonde Matthieu, Taylor Laura, Yan Su, Dunsby Christopher, Weinberg Peter D, Tang Meng-Xing
IEEE Trans Biomed Eng. 2024 Dec;71(12):3446-3456. doi: 10.1109/TBME.2024.3426487. Epub 2024 Nov 21.
Super-resolution ultrasound (SRUS) imaging through localizing and tracking microbubbles, also known as ultrasound localization microscopy (ULM), can produce sub-diffraction resolution images of micro-vessels. We have recently demonstrated 3-D selective SRUS with a matrix array and phase change contrast agents (PCCAs). However, this method is limited to a small field of view (FOV) and by the complex hardware required.
This study proposed 3-D acoustic wave sparsely activated localization microscopy (AWSALM) using PCCAs and a 128+128 row-column-addressed (RCA) array, which offers ultrafast acquisition with over 6 times larger FOV and 4 times reduction in hardware complexity than a 1024-element matrix array. We first validated this method on an in-vitro microflow phantom and subsequently demonstrated non-invasively on a rabbit kidney in-vivo.
Our results show that 3-D AWSALM images of the phantom covering a mm volume can be generated under 5 seconds with an 8 times resolution improvement over the system point spread function. The full volume of the rabbit kidney can be covered to generate 3-D microvascular structure, flow speed and direction super-resolution maps under 15 seconds, combining the large FOV of RCA with the high resolution of SRUS. Additionally, 3-D AWSALM is selective and can visualize the microvasculature within the activation volume and downstream vessels in isolation. Sub-sets of the kidney microvasculature can be imaged through selective activation of PCCAs.
Our study demonstrates large FOV 3-D AWSALM using an RCA probe.
3-D AWSALM offers an unique in-vivo imaging tool for fast, selective and large FOV vascular flow mapping.
通过定位和跟踪微泡的超分辨率超声（SRUS）成像，也称为超声定位显微镜（ULM），可以生成微血管的亚衍射分辨率图像。我们最近展示了使用矩阵阵列和相变造影剂（PCCA）的三维选择性SRUS。然而，该方法限于小视野（FOV）且受所需复杂硬件的限制。
本研究提出了使用PCCA和128 + 128行列寻址（RCA）阵列的三维声波稀疏激活定位显微镜（AWSALM），与1024元素矩阵阵列相比，它提供超快速采集，视野大6倍以上，硬件复杂度降低4倍。我们首先在体外微流模型上验证了该方法，随后在兔肾体内进行了无创演示。
我们的结果表明，在5秒内可以生成覆盖毫米体积的模型的三维AWSALM图像，分辨率比系统点扩散函数提高8倍。结合RCA的大视野和SRUS的高分辨率，在15秒内可以覆盖兔肾的整个体积以生成三维微血管结构、流速和方向超分辨率图。此外，三维AWSALM具有选择性，可以单独可视化激活体积内的微血管和下游血管。通过选择性激活PCCA可以对肾微血管的子集进行成像。
我们的研究展示了使用RCA探头的大视野三维AWSALM。
三维AWSALM为快速、选择性和大视野血管血流映射提供了一种独特的体内成像工具。
