Synthetic-focusing strategies for real-time annular-array imaging.
Synthetic-focusing strategies for real-time annular-array imaging.
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DOI：
10.1109/tuffc.2012.2388
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发表时间：
2012-08
期刊：
影响因子：
--
通讯作者：
Filoux E
中科院分区：
文献类型：
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作者：
Ketterling JA;Filoux E
环形阵列提供了一种以有限数量的元件实现增强的图像质量的手段。依赖于来自各个发射-接收（TR）元件对的波束成形数据的合成聚焦（SF）策略提供了一种在没有专门的TR延迟电子器件的情况下改善图像质量的手段。在这里，SF策略的上下文中检查的高频超声（>15 MHz）的环形阵列组成的五个元素，在18和38 MHz的操作。声场模拟与从线和消声球幻影获得的实验数据进行了比较，横向波束宽度，SNR，对比度噪声比（CNR），和景深（DOF）的值作为深度的函数进行了比较。在每种情况下，针对所有TR组合（总共25个）采集数据，并使用所有25个TR对和外部接收通道被逐个移除的SF利用SF进行处理。结果表明，去除外部接收通道导致横向分辨率的整体退化，SNR的整体降低，并且没有降低DOF，尽管DOF轮廓的幅度降低。CNR>1，并且作为深度的函数保持相当恒定，对于仅中央元件接收的情况，CNR略微降低。18和38 MHz阵列的计算值和测量值之间的相对变化几乎相同。B模式图像的消声体模和体内小鼠胚胎使用全SF与25 TR对或减少TR对的方法显示出最小的定性差异。
Annular arrays provide a means to achieve enhanced image quality with a limited number of elements. Synthetic-focusing (SF) strategies that rely on beamforming data from individual transmit-to-receive (TR) element pairs provide a means to improve image quality without specialized TR delay electronics. Here, SF strategies are examined in the context of high-frequency ultrasound (>15 MHz) annular arrays composed of five elements, operating at 18 and 38 MHz. Acoustic field simulations are compared with experimental data acquired from wire and anechoic-sphere phantoms, and the values of lateral beamwidth, SNR, contrast-to-noise ratio (CNR), and depth of field (DOF) are compared as a function of depth. In each case, data were acquired for all TR combinations (25 in total) and processed with SF using all 25 TR pairs and SF with the outer receive channels removed one by one. The results show that removing the outer receive channels led to an overall degradation of lateral resolution, an overall decrease in SNR, and did not reduce the DOF, although the DOF profile decreased in amplitude. The CNR was >1 and remained fairly constant as a function of depth, with a slight decrease in CNR for the case with just the central element receiving. The relative changes between the calculated and measured quantities were nearly identical for the 18- and 38-MHz arrays. B-mode images of the anechoic phantom and an in vivo mouse embryo using full SF with 25 TR pairs or reduced TR-pair approaches showed minimal qualitative difference.