In Vivo Acoustic Super-Resolution and Super-Resolved Velocity Mapping Using Microbubbles
In Vivo Acoustic Super-Resolution and Super-Resolved Velocity Mapping Using Microbubbles
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DOI：
10.1109/tmi.2014.2359650
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发表时间：
2015-02-01
影响因子：
10.6
通讯作者：
Eckersley, Robert J.
中科院分区：
文献类型：
--
作者：
Christensen-Jeffries, Kirsten;Browning, Richard J.;Eckersley, Robert J.
由于超声波的基本衍射极限，使用标准临床超声（US）成像频率无法分辨微血管结构。在这项工作中，我们使用一个标准的临床US系统进行在体内亚衍射成像的CD 1，雌性小鼠年龄8周，通过定位孤立的US信号从微泡流动在耳朵微血管，并比较我们的结果，光学显微镜。此外，我们开发了一种新的技术，通过跟踪单个气泡通过血管系统，以超分辨率映射血液速度。分辨率从在原始US数据中分别测量的112 μ m和94 μ m的横向和轴向分辨率提高到微血管的超分辨图像，其中血管特征清晰地显示为19 μ m。速度图清楚地区分相邻血管中相反的流动方向和分离的速度分布，从而能够进一步区分在图像中没有空间分离的血管。这种技术克服了衍射极限，提供了一种以超分辨率对微血管系统进行成像的非侵入性手段，深度可达数厘米。在未来，这种方法可以非侵入性成像的病理或治疗变化的微血管在厘米深的体内。
The structure of microvasculature cannot be resolved using standard clinical ultrasound (US) imaging frequencies due to the fundamental diffraction limit of US waves. In this work, we use a standard clinical US system to perform in vivo sub-diffraction imaging on a CD1, female mouse aged eight weeks by localizing isolated US signals from microbubbles flowing within the ear microvasculature, and compare our results to optical microscopy. Furthermore, we develop a new technique to map blood velocity at super-resolution by tracking individual bubbles through the vasculature. Resolution is improved from a measured lateral and axial resolution of 112 mu m and 94 mu m respectively in original US data, to super-resolved images of microvasculature where vessel features as fine as 19 mu m are clearly visualized. Velocity maps clearly distinguish opposing flow direction and separated speed distributions in adjacent vessels, thereby enabling further differentiation between vessels otherwise not spatially separated in the image. This technique overcomes the diffraction limit to provide a noninvasive means of imaging the microvasculature at super-resolution, to depths of many centimeters. In the future, this method could noninvasively image pathological or therapeutic changes in the microvasculature at centimeter depths in vivo.