Feature-adaptive motion tracking of ultrasound image sequences using a deformable mesh
Feature-adaptive motion tracking of ultrasound image sequences using a deformable mesh
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DOI：
10.1109/42.746627
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发表时间：
1998-12
影响因子：
10.6
通讯作者：
Fai Yeung;S. Levinson;D. Fu;K. Parker
中科院分区：
文献类型：
--
作者：
Fai Yeung;S. Levinson;D. Fu;K. Parker
通过利用由下层组织元素的散射产生的超声散斑图案的相关性，理论上可以通过跟踪相关联的散斑图案的表观运动来恢复二维组织运动。然而，由于散斑模式的时间去相关性和医学超声图像固有的低信噪比，散斑跟踪是一个不适定的逆问题。本文研究了使用自适应变形网格的非刚性组织运动从超声图像恢复。将连接网格元素的节点自适应地分配给不太容易受到时间去相关影响的稳定散斑图案。作者采用有限元分析的方法处理不规则网格单元。提出了一种新的可变形块匹配算法，利用拉格朗日元素的高阶描述的局部运动，估计在每个节点的非刚性运动矢量。为了确保运动估计是允许的物理上合理的解决方案，节点位移正则化，通过最小化与网格变形相关联的应变能。基于超声图像的组织模仿幻影和肌肉收缩，并在计算机模拟的实验表明，该算法可以成功地跟踪非刚性位移场。
By exploiting the correlation of ultrasound speckle patterns that result from scattering by underlying tissue elements, two-dimensional tissue motion theoretically can be recovered by tracking the apparent movement of the associated speckle patterns. Speckle tracking, however, is an ill-posed inverse problem because of temporal decorrelation of the speckle patterns and the inherent low signal-to-noise ratio of medical ultrasonic images. This paper investigates the use of an adaptive deformable mesh for nonrigid tissue motion recovery from ultrasound images. The nodes connecting the mesh elements are allocated adaptively to stable speckle patterns that are less susceptible to temporal decorrelation. The authors use the approach of finite clement analysis in manipulating the irregular mesh elements. A novel deformable block matching algorithm, making use of a Lagrange element for higher-order description of local motion, is proposed to estimate a nonrigid motion vector at each node. In order to ensure that the motion estimates are admissible to a physically plausible solution, the nodal displacements are regularized by minimizing the strain energy associated with the mesh deformations. Experiments based on ultrasound images of a tissue mimicking phantom and a muscle undergoing contraction, and on computer simulations, have shown that the proposed algorithm can successfully track nonrigid displacement fields.