摘要
在磁共振(Magnetic resonance,MR)成像过程中,病人的自主运动或生理性运动会使重建的图像产生伪影,严重影响医生的诊断。为了校正MR图像平移运动伪影,本文提出了一种基于差分演化算法的校正方法。首先利用非兴趣区的伪影数据,建立关于K空间偏移相位的约束条件方程组。然后采用差分演化算法搜索最优平移位移量,由此计算出相位偏差量并修正图像。同时提出一个新的价值函数,以此作为演化计算终止的判断条件,实现伪影图像的自动校正。实验结果表明,该算法能够有效地修正含有平移运动伪影的MR图像,且不需要反复的人工掩膜处理。
Motion artifacts produced by patient physiological and physical movements during the magnetic resonance（MR） imaging process apparently damage the diagnosis of doctors. To correct translational motion artifacts, a correction method based on differential evolution algorithm is proposed. Firstly, the method establishes a group of constraint equations to estimate the phase offset of K-space using the data outside of the field of view. Then, the differential evolution algorithm is used to search for optimal translational displacements, the phase offset is calculated and the MR images are corrected. To avoid repetitively manual masking, the method develops a new cost function as the termination condition for the evolutionary computation, thus realizing the automatic correction of MR images. Experimental results demonstrate the method can remove the translational motion artifacts from MR images in a efficient manner without manual masking.
出处
《数据采集与处理》
CSCD
北大核心
2009年第4期519-523,共5页
Journal of Data Acquisition and Processing
关键词
磁共振成像
平移运动伪影
差分演化算法
magnetic resonance imaging
translational motion artifact
differential evolution algorithm
