Ultrasound Contrast Plane Wave Imaging
Ultrasound Contrast Plane Wave Imaging
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DOI：
10.1109/tuffc.2012.2508
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发表时间：
2012-12-01
影响因子：
3.6
通讯作者：
Tanter, Mickael
中科院分区：
文献类型：
--
作者：
Couture, Olivier;Fink, Mathias;Tanter, Mickael
背景：用超声监测微泡在组织脉管系统内的积聚允许分子成像和灌注成像。不幸的是，使用聚焦脉冲的传统成像可能会破坏它试图跟踪的大部分微泡。采用相干合成求和，超快平面波成像可以获得相似的图像质量，同时降低峰值声压和气泡破裂。方法：在这些实验中，微泡在无壁血管体模中流动。在可编程临床扫描仪上获得图像，该扫描仪具有用于常规对比成像的一组逐线聚焦脉冲和适于非线性成像的复合平面波传输。在14和650 kPa峰值负压下以7.5 MHz进行成像。通过比较在不同压力下采集一组100张图像之前和之后的微泡强度来评价微泡的破坏。结果如下：与传统的聚焦脉冲相比，平面波成像破坏50%的微泡所需的声强度高24倍。虽然这两种成像方法产生类似的分辨率，在相同的中断水平，平面波成像显示出更好的对比度。特别是，在类似的中断率（50%后，100个图像），对比度脉冲序列（CPS）与平面波进行了显示与传统的非线性成像相比，提高了11分贝。结论：在图像的每个分辨率单元中，平面波成像将空间峰值声强度分散到更多脉冲上，降低峰值压力，从而保留微泡。这种方法可以通过允许连续监测具有改善的对比度的微泡的积累而有助于分子成像。
Background: Monitoring the accumulation of microbubbles within tissue vasculature with ultrasound allows both molecular and perfusion imaging. Unfortunately, conventional imaging with focused pulses can destroy a large fraction of the microbubbles it is trying to follow. Using coherent synthetic summation, ultrafast plane wave imaging could attain similar image quality, while reducing the peak acoustic pressure and bubble disruption. Method: In these experiments, microbubbles were flowed in a wall-less vessel phantom. Images were obtained on a programmable clinical scanner with a set of line-per-line focused pulses for conventional contrast imaging and with compounded plane wave transmission adapted for nonlinear imaging. Imaging was performed between 14 and 650 kPa peak negative pressure at 7.5 MHz. The disruption of the microbubbles was evaluated by comparing the microbubble intensity before and after acquisition of a set of 100 images at various pressures. Results: The acoustic intensity required to disrupt 50% of the microbubbles was 24 times higher with plane-wave imaging compared with conventional focused pulses. Although both imaging approaches yield similar resolution, at the same disruption level, plane-wave imaging showed better contrast. In particular, at similar disruption ratio (50% after 100 images), contrast-pulse sequencing (CPS) performed with plane waves displayed an improvement of 11 dB compared with conventional nonlinear imaging. Conclusion: In each resolution cell of the image, plane-wave imaging spread the spatial peak acoustic intensity over more pulses, reducing the peak pressure and, hence, preserving the microbubbles. This method could contribute to molecular imaging by allowing the continuous monitoring of the accumulation of microbubbles with improved contrast.