Yue Yong, Clark John W, Khoury Dirar S
Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA.
IEEE Trans Biomed Eng. 2009 Feb;56(2):416-25. doi: 10.1109/TBME.2008.2006036. Epub 2008 Oct 7.
Intracardiac echocardiography (ICE) has proven to be useful for online anatomical imaging during catheterization. Our objective was to develop a speckle tracking method for myocardial motion estimation from ICE image sequences in order to provide a mean for regional functional imaging. Our approach was to solve two problems in motion estimation from 2-D ICE image sequences: nonrigid myocardial deformation and speckle decorrelation. To achieve robust noise resistance, we employed maximum likelihood estimation while fully exploiting ultrasound speckle statistics, and treated the maximization of motion probability as the minimization of an energy function. Nonrigid myocardial deformation was estimated by optimizing this energy function within a framework of parametric elastic registration. Evaluation of the method was carried out using a computer model that synthesized echocardiographic image sequences, and subsequently an animal model that provided continuous ICE images as well as reference measurements using sonomicrometry crystals. In conclusion, accurate estimation of regional myocardial deformation from ICE by novel speckle tracking is feasible. This approach may have important clinical implications for multimodal imaging during catheterization.
心腔内超声心动图(ICE)已被证明在导管插入术期间进行在线解剖成像时很有用。我们的目标是开发一种用于从ICE图像序列估计心肌运动的散斑跟踪方法,以便提供一种进行区域功能成像的手段。我们的方法是解决二维ICE图像序列运动估计中的两个问题:非刚性心肌变形和散斑去相关。为了实现强大的抗噪声能力,我们采用了最大似然估计,同时充分利用超声散斑统计信息,并将运动概率的最大化视为能量函数的最小化。通过在参数弹性配准框架内优化该能量函数来估计非刚性心肌变形。使用合成超声心动图图像序列的计算机模型,随后使用提供连续ICE图像以及使用超声测微晶体进行参考测量的动物模型对该方法进行评估。总之,通过新颖的散斑跟踪从ICE准确估计区域心肌变形是可行的。这种方法可能对导管插入术期间的多模态成像具有重要的临床意义。