Ultrasonically encoded photoacoustic flowgraphy in biological tissue.
Ultrasonically encoded photoacoustic flowgraphy in biological tissue.
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DOI：
10.1103/physrevlett.111.204301
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发表时间：
2013-11-15
影响因子：
8.6
通讯作者：
Wang LV
中科院分区：
文献类型：
--
作者：
Wang L;Xia J;Yao J;Maslov KI;Wang LV
血流速度是一个重要的功能参数。多普勒超声流量计缺乏足够的灵敏度来减缓深部组织中的血流（每秒几毫米到几十毫米）。为了应对这一挑战，我们开发了超声编码光声血流图结合超声热标记与光声成像。聚焦超声在声学吸收流体中产生受限热源。热波传播的流动和直接可视化的伪彩色使用光声计算机断层扫描。多普勒频移被用来计算流速。这种方法只需要声吸收和光吸收，因此适用于连续流体。成功测量了低至0.24 mm·s-1的血流速度。在5 mm厚的鸡胸组织下进行了深血流成像实验。
Blood flow speed is an important functional parameter. Doppler ultrasound flowmetry lacks sufficient sensitivity to slow blood flow (several to tens of millimeters per second) in deep tissue. To address this challenge, we developed ultrasonically encoded photoacoustic flowgraphy combining ultrasonic thermal tagging with photoacoustic imaging. Focused ultrasound generates a confined heat source in acoustically absorptive fluid. Thermal waves propagate with the flow and are directly visualized in pseudo color using photoacoustic computed tomography. The Doppler shift is employed to calculate the flow speed. This method requires only acoustic and optical absorption, and thus is applicable to continuous fluid. A blood flow speed as low as 0.24 mm·s−1 was successfully measured. Deep blood flow imaging was experimentally demonstrated under 5-mm-thick chicken breast tissue.