IEEE Trans Ultrason Ferroelectr Freq Control. 2018 Jul;65(7):1182-1192. doi: 10.1109/TUFFC.2018.2836384.
A double-curved diverging lens over the flat row-column-addressed (RCA) 2-D array can extend its inherent rectilinear 3-D imaging field of view (FOV) to a curvilinear volume region, which is necessary for applications such as abdominal and cardiac imaging. Two concave lenses with radii of 12.7 and 25.4 mm were manufactured using RTV664 silicone. The diverging properties of the lenses were evaluated based on simulations and measurements on several phantoms. The measured FOV for both lenses in contact with tissue mimicking phantom was less than 15% different from the theoretical predictions, i.e., a curvilinear FOV of and for the 12.7- and 25.4-mm radii lenses. A synthetic aperture imaging sequence with single-element transmissions was designed for imaging down to 140 mm at a volume rate of 88 Hz. The performance was evaluated in terms of signal-to-noise ratio, FOV, and full-width at half-maximum (FWHM) of a focused beam. The penetration depths in a tissue mimicking phantom with 0.5-dB/(cm MHz) attenuation were 100 and 125 mm for the lenses with radii of 12.7 and 25.4 mm. The azimuth, elevation, and radial FWHM at 43-mm depth were (5.8, 5.8, 1) and (6, 6, 1) . The results of this study confirm that the proposed lens approach is an effective method for increasing the FOV, when imaging with RCA 2-D arrays.
一种在平面行-列寻址（RCA）二维阵列上的双弯曲发散透镜可以将其固有直线 3D 成像视场（FOV）扩展到曲线体积区域，这对于腹部和心脏成像等应用是必要的。两个半径为 12.7 和 25.4mm 的凹透镜是使用 RTV664 硅酮制造的。根据对几个模型的模拟和测量，评估了透镜的发散特性。与组织模拟模型接触的两种透镜的测量 FOV 与理论预测值相差不到 15%，即 12.7- 和 25.4-mm 半径透镜的曲线 FOV 分别为 和 。设计了具有单元素传输的合成孔径成像序列，用于在体积速率为 88Hz 时成像至 140mm。根据信噪比、FOV 和聚焦光束的半最大值全宽（FWHM）评估了性能。在具有 0.5dB/（cmMHz）衰减的组织模拟模型中的穿透深度分别为 100mm 和 125mm，半径为 12.7mm 和 25.4mm 的透镜。在 43mm 深度处的方位角、仰角和径向 FWHM 分别为（5.8，5.8，1）和（6，6，1）。本研究的结果证实，当使用 RCA 二维阵列进行成像时，所提出的透镜方法是增加 FOV 的有效方法。
