A parallelizable real-time motion tracking algorithm with applications to ultrasonic strain imaging
A parallelizable real-time motion tracking algorithm with applications to ultrasonic strain imaging
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DOI：
10.1088/0031-9155/52/13/008
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发表时间：
2007-07-07
影响因子：
3.5
通讯作者：
Hall, T. J.
中科院分区：
文献类型：
--
作者：
Jiang, J.;Hall, T. J.
基于超声的机械应变成像系统利用来自常规诊断超声系统的信号来对组织弹性对比进行成像，这提供了新的有诊断价值的信息。先前的工作（Hall等人2003 Ultrasound Med.Biol.29427，Zhu和Hall 2002 Ultrason.成像24 161）表明，单轴变形与最小的仰角运动是首选的乳房应变成像和实时应变图像反馈给操作员是很重要的，以实现这一目标。这里报告的工作增强了实时斑点跟踪算法与两个显着的修改。一个基本的变化是，所提出的算法是基于列的算法（列由平行于超声波束方向的数据线定义，即A线），而不是基于行的算法（行由垂直于超声波束方向的数据线定义）。然后，从其相邻列的位移估计提供了很好的指导运动跟踪在一个显着减少搜索区域，以减少计算成本。因此，位移估计的过程可以自然地分成至少两个单独的任务，并行计算，从感兴趣区域（ROI）的中心向外传播。该算法已在WindowsR（R）系统上作为独立的ANSIC++程序实现和优化。使用数值和组织模拟体模以及体内组织数据的初步测试结果表明，可以以超过我们之前方法的帧率（10帧s（-1））一致地获得高对比度应变图像。
Ultrasound-based mechanical strain imaging systems utilize signals from conventional diagnostic ultrasound systems to image tissue elasticity contrast that provides new diagnostically valuable information. Previous works ( Hall et al 2003 Ultrasound Med. Biol. 29 427, Zhu and Hall 2002 Ultrason. Imaging 24 161) demonstrated that uniaxial deformation with minimal elevation motion is preferred for breast strain imaging and real-time strain image feedback to operators is important to accomplish this goal. The work reported here enhances the real-time speckle tracking algorithm with two significant modifications. One fundamental change is that the proposed algorithm is a column-based algorithm (a column is defined by a line of data parallel to the ultrasound beam direction, i.e. an A-line), as opposed to a row-based algorithm ( a row is defined by a line of data perpendicular to the ultrasound beam direction). Then, displacement estimates from its adjacent columns provide good guidance for motion tracking in a significantly reduced search region to reduce computational cost. Consequently, the process of displacement estimation can be naturally split into at least two separated tasks, computed in parallel, propagating outward from the center of the region of interest ( ROI). The proposed algorithm has been implemented and optimized in a WindowsR (R) system as a stand-alone ANSIC++ program. Results of preliminary tests, using numerical and tissue-mimicking phantoms, and in vivo tissue data, suggest that high contrast strain images can be consistently obtained with frame rates (10 frames s(-1)) that exceed our previous methods.