Chen Yinran, Zhuang Zichen, Luo Jianwen, Luo Xiongbiao
IEEE Trans Image Process. 2023;32:4501-4516. doi: 10.1109/TIP.2023.3300591. Epub 2023 Aug 10.
Volumetric (3D) ultrasound imaging using a 2D matrix array probe is increasingly developed for various clinical procedures. However, 3D ultrasound imaging suffers from motion artifacts due to tissue motions and a relatively low frame rate. Current Doppler-based motion compensation (MoCo) methods only allow 1D compensation in the in-range dimension. In this work, we propose a new 3D-MoCo framework that combines 3D velocity field estimation and a two-step compensation strategy for 3D diverging wave compounding imaging. Specifically, our framework explores two constraints of a round-trip scan sequence of 3D diverging waves, i.e., Doppler and pair-wise optical flow, to formulate the estimation of the 3D velocity fields as a global optimization problem, which is further regularized by the divergence-free and first-order smoothness. The two-step compensation strategy is to first compensate for the 1D displacements in the in-range dimension and then the 2D displacements in the two mutually orthogonal cross-range dimensions. Systematical in-silico experiments were conducted to validate the effectiveness of our proposed 3D-MoCo method. The results demonstrate that our 3D-MoCo method achieves higher image contrast, higher structural similarity, and better speckle patterns than the corresponding 1D-MoCo method. Particularly, the 2D cross-range compensation is effective for fully recovering image quality.
使用二维矩阵阵列探头的容积（三维）超声成像在各种临床检查中得到了越来越广泛的应用。然而，三维超声成像会因组织运动和相对较低的帧率而产生运动伪影。目前基于多普勒的运动补偿（MoCo）方法仅允许在距离维度上进行一维补偿。在这项工作中，我们提出了一种新的三维MoCo框架，该框架结合了三维速度场估计和用于三维发散波复合成像的两步补偿策略。具体而言，我们的框架利用三维发散波往返扫描序列的两个约束条件，即多普勒和成对光流，将三维速度场的估计表述为一个全局优化问题，并通过无散度和一阶平滑性进一步进行正则化。两步补偿策略是首先补偿距离维度上的一维位移，然后补偿两个相互正交的横向维度上的二维位移。我们进行了系统的计算机模拟实验，以验证我们提出的三维MoCo方法的有效性。结果表明，与相应的一维MoCo方法相比，我们的三维MoCo方法具有更高的图像对比度、更高的结构相似性和更好的散斑模式。特别是，二维横向补偿对于完全恢复图像质量是有效的。
