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回波平面成像中基于相位恢复的ghost伪影校正

DOI: 10.11834/jig.20060359

Keywords: 平面回波成像,ghost伪影,磁共振成像,相位恢复

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Abstract:

EPI技术是基于方向相反的频率读出的梯度来交替采集MR信号的奇、偶回波,但是,由于成像物体的磁敏感性、化学位移及磁场曰。的不均匀性等因素的影响会导致奇、偶回波之间产生相位移动,因而会产生ghost伪影。为了消除成像中产生的ghost伪影,提出了基于相位恢复的ghost伪影消除方法,即用数学形态学的方法确定支撑域,支撑域外的ghost伪影被置为零,首先获得模板图像;然后以最小熵为收敛准则运行迭代算法,直到得到满意的图像。实验证明,运用该方法能够明显地降低ghost伪影,可见这种方法是可行的。

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