Chen Ting, Chung Sohae, Axel Leon
Radiology Department, New York University, School of Medicine 600A 650 First Ave, New York City, NY 10016, USA.
Med Image Comput Comput Assist Interv. 2007;10(Pt 2):469-76. doi: 10.1007/978-3-540-75759-7_57.
The tracking and reconstruction of myocardial motion is critical to the diagnosis and treatment of heart disease. Currently, little has been done for the analysis of motion in long axis (LA) cardiac images. We propose a new fully automated motion reconstruction method for grid- tagged MRI that combines Gabor filters and deformable models. First, we use a Gabor filter bank to generate the corresponding phase map in the myocardium and estimate the location of grid tag intersections. Second, we use a non-rigid registration module driven by thin plate splines (TPS) to generate a transformation function between tag intersections in two consecutive images. Third, deformable spline models are initialized using Fourier domain analysis and tracked during the cardiac cycle using the TPS generated transformation function. The splines will then locally deform under the influence of gradient flow and image phase information. The final motion is decomposed into tangential and normal components corresponding to the local orientation of the heart wall. The new method has been tested on LA phantoms and in vivo heart data, and its performance has been quantitatively validated. The results show that our method can reconstruct the motion field in LA cardiac tagged MR images accurately and efficiently.
心肌运动的跟踪与重建对于心脏病的诊断和治疗至关重要。目前，在长轴（LA）心脏图像的运动分析方面所做的工作很少。我们提出了一种用于网格标记磁共振成像（MRI）的全新全自动运动重建方法，该方法结合了Gabor滤波器和可变形模型。首先，我们使用Gabor滤波器组在心肌中生成相应的相位图，并估计网格标记交点的位置。其次，我们使用由薄板样条（TPS）驱动的非刚性配准模块来生成两个连续图像中标记交点之间的变换函数。第三，使用傅里叶域分析初始化可变形样条模型，并在心动周期中使用TPS生成的变换函数对其进行跟踪。然后，样条将在梯度流和图像相位信息的影响下局部变形。最终的运动被分解为与心脏壁局部方向相对应的切向和法向分量。该新方法已在LA模型和体内心脏数据上进行了测试，其性能已得到定量验证。结果表明，我们的方法能够准确、高效地重建LA心脏标记MR图像中的运动场。
