Feinberg David A, Reese Timothy G, Wedeen Van J
Advanced MRI Technologies, LLC, Sebastopol, California 95472, USA.
Magn Reson Med. 2002 Jul;48(1):1-5. doi: 10.1002/mrm.10227.
A method to encode multiple two-dimensional Fourier transform (2D FT) images within a single echo train is presented. This new method, simultaneous echo refocusing (SER), is a departure from prior echo planar image (EPI) sequences which use repeated single-shot echo trains for multislice imaging. SER simultaneously acquires multiple slices in a single-shot echo train utilizing a shared refocusing process. The SER technique acquires data faster than conventional multislice EPI since it uses fewer gradient switchings and fewer preparation pulses such as diffusion gradients. SER introduces a new capability to simultaneously record multiple spatially separated sources of physiologic information in subsecond image acquisitions, which enables several applications that are dependent on temporal coherence in MRI data including velocity vector field mapping and brain activation mapping.
本文提出了一种在单个回波链内编码多个二维傅里叶变换（2D FT）图像的方法。这种新方法，即同步回波重聚焦（SER），与之前的回波平面成像（EPI）序列不同，后者使用重复的单激发回波链进行多层成像。SER在单激发回波链中利用共享的重聚焦过程同时采集多个层面。由于SER使用较少的梯度切换和较少的准备脉冲（如扩散梯度），因此其采集数据的速度比传统多层EPI更快。SER引入了一种新能力，能够在亚秒级图像采集中同时记录多个空间分离的生理信息源，这使得一些依赖于MRI数据时间相干性的应用成为可能，包括速度矢量场映射和脑激活映射。
