Synthetic aperture imaging with a virtual source element
Synthetic aperture imaging with a virtual source element
复制标题
使用虚拟源元件的合成孔径成像
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
W. O’Brien
中科院分区：
文献类型：
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作者：
C. H. Frazier;W. O’Brien
目前的超声成像有两种模式：传统的b扫描成像与聚焦换能器或阵列成像使用波束成形处理来实现焦点。传统的b模成像受限于聚焦深度，而合成孔径成像受限于低信噪比。提出了一种将这两种技术结合起来的新技术来克服聚焦深度的限制。新技术通过将焦点视为虚元来聚焦换能器焦点以外的区域。本文研究了焦点作为虚拟元素的使用，考虑了焦点作为虚拟元素的模型，使用消去权值来降低副瓣，以及处理后图像的信噪比。使用水浴钨丝收集的数据，发现在获得可接受的信噪比的同时，可以获得与焦点分辨率相当的分辨率。去尖化可以降低侧叶，但只会降低侧叶分辨力。通过这些实验，虚拟源已被证明在响应合成孔径处理技术时表现出与实际换能器元件相同的行为。
Currently ultrasonic imaging is performed in one of two modes: conventional B-scan imaging with a focused transducer or array imaging using beamforming processing to achieve the focus. Conventional B-mode imaging suffers from a limited depth of focus while synthetic aperture imaging is limited by a low signal to noise ratio (SNR). A new technique has been proposed that combines these two techniques to overcome the limited depth of focus. The new technique involves focusing the region beyond the focus of the transducer by considering the focus a virtual element. In this paper, the use of the focus as a virtual element is examined, considering the model for the focus as an element, the use of apodization weights to lower sidelobes, and the SNR of the processed image. Using data collected with tungsten wires in a waterbath, it was found that resolution comparable to the resolution at the focus could be achieved while obtaining an acceptable SNR. Apodization was found to lower the sidelobes, but only at the expense of lateral resolution. With these experiments, the virtual source has been shown to exhibit the same behavior as an actual transducer element in response to synthetic aperture processing techniques.