Hedley M, Yan H
School of Electrical Engineering, University of Sydney, NSW, Australia.
Australas Phys Eng Sci Med. 1990 Dec;13(4):177-84.
The quality of Magnetic Resonance imaging systems has improved to the point that the motion is the most important limitation in many examinations. Gross movements of the patient cause a ghost artifact in the image which can interfere with the diagnosis. In this paper a new method is presented to suppress the translational motion artifact caused by gross movements. The method uses postprocessing on a standard two-dimensional Fourier transform image. It is shown that translational motion causes an additional phase factor in the detected signal and that this phase error can be removed using an iterative algorithm of generalised projections. The method has been tested using computer simulations and successfully removed most of the artifact, even in the presence of noise.
磁共振成像系统的质量已经提升到这样一个程度，即运动成为许多检查中最为重要的限制因素。患者的大幅度运动在图像中会产生鬼影伪影，这可能会干扰诊断。本文提出了一种新方法来抑制由大幅度运动引起的平移运动伪影。该方法在标准二维傅里叶变换图像上进行后处理。结果表明，平移运动会在检测信号中产生一个额外的相位因子，并且可以使用广义投影的迭代算法消除这个相位误差。该方法已通过计算机模拟进行测试，即使在存在噪声的情况下也能成功去除大部分伪影。
