【摘要】 Ghost伪影是回波平面成像(EPI)中一个很普遍的伪影,一般的方法是在扫描实际图像前利用参考扫描的方法对伪影进行消除。本研究提出了一个利用K空间原始数据的共轭对称性来消除ghost伪影的方法,且可以自动进行而不需要参考扫描。理想的K空间数据是共轭对称的。首先利用K空间的上述特性估计产生ghost伪影的K空间数据奇数和偶数行间的相位差,然后用迭代的方法对K空间数据进行校正,直到达到最好的ghost伪影消除效果。实验证明,所提出的方法可以有效的对ghost伪影进行消除。更多还原

【Abstract】 The ghost artifact is one of the most common artifacts for echo planar imaging.Most methods generally remove this kind of artifact with the aid of a reference scan preceding the actual image acquisition.In this work,an automated free-scan-reference method was proposed to reduce ghost artifact using the conjugate symmetry of the raw data in k-space.The proposed method utilized the conjugate symmetry of the K-space to estimate the phase difference between the odd lines and even lines of the K-space.Subsequently,we used the iterative method to correct the K-space until experiment obtains the best results.Results from simulation and in vivo experiments showed that the new method could significantly reduce the ghost artifact.更多还原