Reber P J, Wong E C, Buxton R B, Frank L R
Department of Psychiatry, University of California, San Diego 92103, USA.
Magn Reson Med. 1998 Feb;39(2):328-30. doi: 10.1002/mrm.1910390223.
We present, here, a simple method for measurement and correction of off-resonance related geometric distortion in echo-planar imaging (EPI). This method uses high signal-to-noise ratio (SNR) EPI-based field maps, rapidly acquired using a series of gradient recalled images collected across a range of TE values. This field map is distorted in the same manner as the EPI images to be unwarped, providing a direct look-up table for the correct location of each pixel of data. This method adds very little scan time and is robust and easy to implement.
在此，我们提出一种用于测量和校正回波平面成像（EPI）中与失谐相关的几何失真的简单方法。该方法使用基于高信噪比（SNR）EPI的场图，通过在一系列TE值上采集的一系列梯度回波图像快速获取。该场图与要去扭曲的EPI图像以相同方式失真，为每个数据像素的正确位置提供了直接查找表。该方法增加的扫描时间极少，并且稳健且易于实施。
