Toric focusing for radiation force applications using a toric lens coupled to a spherically focused transducer.
Toric focusing for radiation force applications using a toric lens coupled to a spherically focused transducer.
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使用与球面聚焦传感器耦合的复曲面透镜进行辐射力应用的复曲面聚焦。
DOI：
10.1109/tuffc.2014.006721
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
O'Donnell,Matthew
中科院分区：
文献类型：
--
作者：
Arnal,Bastien;Nguyen,Thu-Mai;O'Donnell,Matthew
使用辐射力的动态弹性成像需要在数百微秒期间在几兆帕斯卡的压力下聚焦超声场。在这里，我们解决的重要性的焦点几何。虽然通常没有控制的海拔焦点宽度在产生组织的机械响应，我们提出了一种可调的方法来适应焦点的几何形状，可以显着提高辐射力的效率。几个薄的，在内部制造的聚二甲基硅氧烷透镜的设计，以修改球形换能器的焦点。他们表现出低吸收和焦斑宽度扩展到8倍的高度方向。辐射力实验表明，在具有类似剪切波谱的组织模拟体模中使用相同的压力水平，组织位移增加了8倍，这意味着它不会影响弹性成像分辨率。我们的研究结果表明，较大的组织反应，可以获得一个给定的压力水平，或类似的反应，可以达到一个低得多的机械指数（MI）。我们设想，这项工作将影响3-D弹性成像使用2-D相控阵列，在这种成形可以实现电子自适应优化的潜力。
Dynamic elastography using radiation force requires that an ultrasound field be focused during hundreds of microseconds at a pressure of several megapascals. Here, we address the importance of the focal geometry. Although there is usually no control of the elevational focal width in generating a tissue mechanical response, we propose a tunable approach to adapt the focus geometry that can significantly improve radiation force efficiency. Several thin, in-house-made polydimethylsiloxane lenses were designed to modify the focal spot of a spherical transducer. They exhibited low absorption and the focal spot widths were extended up to 8-fold in the elevation direction. Radiation force experiments demonstrated an 8-fold increase in tissue displacements using the same pressure level in a tissue-mimicking phantom with a similar shear wave spectrum, meaning it does not affect elastography resolution. Our results demonstrate that larger tissue responses can be obtained for a given pressure level, or that similar response can be reached at a much lower mechanical index (MI). We envision that this work will impact 3-D elastography using 2-D phased arrays, where such shaping can be achieved electronically with the potential for adaptive optimization.