Van de Walle R, Lemahieu I, Achten E
Department of Electronics and Information Systems, University of Ghent, Belgium.
Technol Health Care. 1997 Dec;5(6):419-35.
Magnetic resonance (MR) imaging is a non-invasive diagnostic tool which is widely used nowadays. In this paper, the basic principles of MR imaging are explained and it is shown how images can be reconstructed in case of standard 2D Fourier Transform (2DFT) imaging. Several aspects of MR signal encoding are described. Unfortunately, motion of the patient during a magnetic resonance experiment often causes severe artifacts in the images. For example, in 2DFT imaging blurring and ghosting are seen and the appearance of motion artifacts remains one of the major drawbacks in MR imaging. Several methods to reduce motion artifacts in MR imaging have been proposed in the past. An overview of the principles on which these methods are based is given in this paper. Both post-processing methods and techniques that rely on gating or the use of alternative acquisition schemes such as projection reconstruction are discussed.
磁共振（MR）成像如今是一种广泛使用的非侵入性诊断工具。本文解释了MR成像的基本原理，并展示了在标准二维傅里叶变换（2DFT）成像情况下如何重建图像。描述了MR信号编码的几个方面。不幸的是，在磁共振实验期间患者的运动常常会在图像中产生严重伪影。例如，在2DFT成像中会出现模糊和重影，并且运动伪影的出现仍然是MR成像的主要缺点之一。过去已经提出了几种减少MR成像中运动伪影的方法。本文给出了这些方法所基于原理的概述。讨论了后处理方法以及依赖门控或使用诸如投影重建等替代采集方案的技术。
