Yang W, Smith M R
Department of Electrical and Computer Engineering, University of Calgary, Alberta, Canada.
IEEE Trans Med Imaging. 2000 Jun;19(6):577-84. doi: 10.1109/42.870663.
Motion artefact suppression remains an active topic in MRI. In this paper, we suggest that certain nonrigid, or spatially variant, characteristics of motion of an object can be represented by extending the work of Mitsa et al. This empirical extension uses a ghost distortion transfer function (GTDF) applied to the k-space (frequency domain) data. We demonstrate the variety of ghost characteristics that can be generated from various two-dimensional (2-D) GTDF's. The distortion transfer function for periodic motion along the Z-axis can be determined from the nonoverlapped portions of the ghost and central image. It required a GDTF with the shape of a belt bandpass filter to produce an image corresponding to the ghosts of a volunteer's abdomen image corrupted by unknown respiratory motion artefacts. The preliminary results of a composite method of motion artefact suppression are presented. The artefact suppression was successful for ghost images described by a GDTF have a low-pass nature, but less successful with ghosts have a GDTF of a bandpass nature.
运动伪影抑制仍是磁共振成像（MRI）领域的一个活跃研究课题。在本文中，我们提出物体运动的某些非刚性或空间变化特性可以通过扩展米察等人的工作来表示。这种经验性扩展使用了应用于k空间（频域）数据的鬼影失真传递函数（GTDF）。我们展示了从各种二维（2-D）GTDF中可以生成的多种鬼影特性。沿Z轴周期性运动的失真传递函数可以从鬼影和中心图像的非重叠部分确定。需要一个带通滤波器形状的GDTF来生成与因未知呼吸运动伪影而损坏的志愿者腹部图像的鬼影相对应的图像。本文给出了运动伪影抑制复合方法的初步结果。对于具有低通性质的GDTF描述的鬼影图像，伪影抑制是成功的，但对于具有带通性质的GDTF的鬼影，抑制效果较差。
