Meunier J
Department of Computer Science, Université de Montréal, Canada.
Phys Med Biol. 1998 May;43(5):1241-54. doi: 10.1088/0031-9155/43/5/014.
The potential of ultrasonic image speckle tracking to characterize tissue dynamics has been illustrated and validated elsewhere. In this paper we wish to extend this speckle tracking methodology to 3D. To investigate the feasibility of such an approach we first model the image formation process and simulate the 3D speckle motion inherent to tissue linear transformations (translation, rotation and deformation). It is shown that tissue axial rotation and translation are perfectly correlated with the tissue speckle motion while tissue deformation and non-axial rotations corrupt the speckle pattern with a motion-induced noise and are therefore more difficult to track when large motions are concerned. Furthermore, in the framework of our model, our results indicate that short ultrasound pulses with low frequencies and small beamwidths are more desirable for a speckle tracking methodology. The feasibility of speckle tracking is illustrated with an optical flow algorithm. A theoretical study of the correlation between various linear transformations of the tissue and the corresponding ultrasonic speckle motions is also performed.
超声图像散斑跟踪用于表征组织动力学的潜力已在其他地方得到说明和验证。在本文中，我们希望将这种散斑跟踪方法扩展到三维。为了研究这种方法的可行性，我们首先对图像形成过程进行建模，并模拟组织线性变换（平移、旋转和变形）中固有的三维散斑运动。结果表明，组织轴向旋转和平移与组织散斑运动完全相关，而组织变形和非轴向旋转会因运动引起的噪声破坏散斑图案，因此在涉及大运动时更难跟踪。此外，在我们的模型框架内，我们的结果表明，对于散斑跟踪方法，低频和小束宽的短超声脉冲更可取。用光流算法说明了散斑跟踪的可行性。还对组织的各种线性变换与相应超声散斑运动之间的相关性进行了理论研究。
