Xiang Q S, Bronskill M J, Henkelman R M
Department of Medical Biophysics, University of Toronto, Ontario, Canada.
J Magn Reson Imaging. 1993 Nov-Dec;3(6):900-6. doi: 10.1002/jmri.1880030618.
A two-point interference method is introduced for suppression of ghosting due to motion in magnetic resonance imaging. The method requires only two time-interleaved data acquisitions, without any monitoring of the motion. A postprocessing technique is used to produce a weighted sum of the two acquired images, in which ghosts are suppressed by interference through an automatic regional tuning procedure. The appropriate complex weighting factors are regionally chosen by minimizing the "gradient energy," which is defined as the sum of squared pixel values in the partial-derivative maps. The method was tested in both phantoms and volunteers with a variety of imaging protocols. The level of ghost suppression with the two-point method was found to be comparable to that of the three-point method described previously by the authors.
本文介绍了一种用于抑制磁共振成像中运动所致重影的两点干涉法。该方法仅需两次时间交错的数据采集，无需对运动进行任何监测。采用一种后处理技术来生成两幅采集图像的加权和，其中通过自动区域调谐程序的干涉来抑制重影。通过最小化“梯度能量”（定义为偏导数图中像素值的平方和）来区域选择合适的复加权因子。该方法在多种成像协议的体模和志愿者中进行了测试。发现两点法的重影抑制水平与作者之前描述的三点法相当。
