Awad Samer I, Yen Jesse T
University of Southern California, Viterbi School of Engineering, Los Angeles, CA 90089-1111, USA.
Ultrason Imaging. 2009 Apr;31(2):120-30. doi: 10.1177/016173460903100203.
2-D spatial compounding has long been investigated to reduce speckle in ultrasound images. To further reduce speckle, several 3-D spatial compounding studies using 1-D and 1.5 D arrays with mechanical translation and position tracking have been reported. However, the fixed elevational focus and mechanical translation can degrade image quality in elevation. Using 2-D arrays, a better elevational resolution can be achieved with electronic focusing. Furthermore, 2-D arrays can generate greater number of independent images than 1-D arrays and the need for mechanical scanning is eliminated. In this paper, we present our 3-D spatial compounding images of two gel-based contrast phantoms and one resolution phantom. These images were acquired using a prototype 4 cm x 4 cm ultrasonic row-column prototype 2-D array operating at 5 MHz. Compounding nine decorrelated volumes showed a speckle signal-to-noise ratio (SNR) improvement of 2.68. The average improvement of the lesion contrast-to-noise ratio (CNR) was 2.45. However, using a smaller aperture to generate these volumes worsened the lateral resolution as predicted by theory.
长期以来，二维空间复合技术一直被用于减少超声图像中的斑点噪声。为了进一步减少斑点噪声，已有多项关于三维空间复合技术的研究报道，这些研究使用一维和1.5维阵列，并结合机械平移和位置跟踪。然而，固定的仰角聚焦和机械平移会降低仰角方向的图像质量。使用二维阵列，通过电子聚焦可以获得更好的仰角分辨率。此外，二维阵列能够比一维阵列生成更多数量的独立图像，并且无需机械扫描。在本文中，我们展示了基于两种凝胶的对比体模和一种分辨率体模的三维空间复合图像。这些图像是使用一个4厘米×4厘米的原型超声行列二维阵列采集的，该阵列工作频率为5兆赫。对九个去相关体积进行复合后，斑点信号噪声比（SNR）提高了2.68。病变对比噪声比（CNR）的平均提高值为2.45。然而，正如理论预测的那样，使用较小孔径来生成这些体积会使横向分辨率变差。
