Bohs L N, Trahey G E
Department of Biomedical Engineering, Duke University, Durham, NC 27706.
IEEE Trans Biomed Eng. 1991 Mar;38(3):280-6. doi: 10.1109/10.133210.
Tracking the speckle patterns produced by moving targets has been shown effective for angle independent imaging of blood flow and tissue motion. While speckle tracking overcomes major limitations of Doppler-based flow imaging, the computational complexity of commonly used cross correlation algorithms currently limits it to off-line studies. A much simpler algorithm for angle independent motion imaging is described in this paper. This method requires only one absolute difference operation per pixel, compared to eight operations for normalized cross correlation. Quantitative studies using speckle-generating targets translated by fixed amounts both axially and laterally indicate that the technique tracks moving speckle as accurately as correlation. Color flow images generated from clinical blood and liver data highlight the success of the technique for tracking both large and small motions in two dimensions. The algorithm's suitability for implementation in digital hardware makes possible the development of clinical instruments for angle independent ultrasonic imaging of blood flow and tissue motion in real time.
跟踪移动目标产生的散斑图案已被证明对血流和组织运动的角度无关成像有效。虽然散斑跟踪克服了基于多普勒的血流成像的主要局限性，但目前常用的互相关算法的计算复杂性将其限制在离线研究中。本文描述了一种用于角度无关运动成像的简单得多的算法。与归一化互相关的八个操作相比，该方法每个像素仅需要一个绝对差操作。使用沿轴向和横向固定量平移的散斑生成目标进行的定量研究表明，该技术跟踪移动散斑的准确性与相关性相同。从临床血液和肝脏数据生成的彩色血流图像突出了该技术在二维中跟踪大小运动的成功。该算法适用于数字硬件实现，使得开发用于实时角度无关的血流和组织运动超声成像的临床仪器成为可能。
