在心脏核磁共振图像分析中，标记线的跟踪是心肌运动分析及3维运动重建的重要步骤。为了提高心脏标记线跟踪的准确性，首先使用改进的基于动力学方程的主动轮廓模型来对标记线进行跟踪，并根据标记线的特点，引入了3种弹性势能，然后采用了新的内能函数，并使用新的方法来产生图像势能，由于改变了原模型中轮廓线初始速度为零的假设，并引入了光流估计作为轮廓的初始速度，从而提高了跟踪结果的准确性。对多序列心脏收缩期核磁共振图像的实验结果表明，该算法可以获得较好的跟踪效果。

In cardiac Magnetic Resonance Image analysis, tracking tag motion is an important step in tissue motion analysis and 3 D motion reconstruction. The paper gives a method using active contour model based on kinetic function to track the tag, and uses three kinds of elastic potential energy, new internal energy and new image energy. The paper also changes the assumption that the initial velocity is zero and takes the optical flow as the velocity, which improves the veracity of the arithmetic. The method is tested on several sequences of cardiac systole MRI. The result indicates the method is effect.