Computer simulation study on Motion correction of MRI by Three dimensional data acquisition

为了抑制磁共振成像中的穿透平面运动伪影，对三维运动校正技术进行了计算机仿真研究。三维数据采集在绕k空间中心旋转的矩形块内对球面空间进行连续采样。低空间分辨率图像通过三个平移和三个旋转的三维位移错位的矩形块数据重建。利用这些低空间分辨率图像与由无3D位移的矩形块数据重建的矩形块数据之间的相关系数来衡量矩形块数据的错位。假设目标在回波序列长度(ETL)的数据采集期间是静止的，并且仅在每个数据采样周期和随后的激励射频(RF)脉冲之间的静止期内发生目标运动。三维运动校正对于磁共振成像中物体的平面运动和穿平面运动都是有效的。

A computer simulation study of a three dimensional (3D) motion correction technique was carried out to suppress through-plane motion artifacts in MRI. The 3D data acquisition sampled spherical space successively within a rectangular block that rotated around the center of k-space. Low spatial resolution images were reconstructed with rectangular block data misaligned by 3D displacement of three translations and three rotations. Misalignments of rectangular block data were measured by correlation coefficient between these low spatial resolution images and one reconstructed with rectangular block data without 3D displacement. It was assumed that the object was stationary during data acquisition of the echo train length (ETL) and object motion occurred only during the quiescent period between each data-sampling period and the following excitation radio frequency (RF) pulse. A 3D motion correction is effective for bothin-plane and through-plane object motion in MRI.