Deichmann R, Schwarzbauer C, Turner R
Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, London WC1N 3BG, UK.
Neuroimage. 2004 Feb;21(2):757-67. doi: 10.1016/j.neuroimage.2003.09.062.
An algorithm for the optimisation of 3D Modified Driven Equilibrium Fourier Transform (MDEFT) sequences for T1-weighted anatomical brain imaging is presented. Imaging parameters are optimised for a clinical whole body scanner and a clinical head scanner operating at 1.5 and 3 T, respectively. In vivo studies show that the resulting sequences allow for the whole brain acquisition of anatomical scans with an isotropic resolution of 1 mm and high contrast-to-noise ratio (CNR) in an acceptable scan time of 12 min. Typical problems related to the scanner-specific hardware configurations are discussed in detail, especially the occurrence of flow artefacts in images acquired with head transmit coils and the enhancement of scalp intensities in images acquired with phased array receive coils. It is shown both theoretically and experimentally that these problems can be avoided by using spin tagging and fat saturation.
本文提出了一种用于优化三维修正驱动平衡傅里叶变换（MDEFT）序列以进行T1加权脑部解剖成像的算法。成像参数分别针对临床全身扫描仪和工作于1.5 T及3 T的临床头部扫描仪进行了优化。体内研究表明，所得序列能够在12分钟的可接受扫描时间内实现全脑解剖扫描的采集，各向同性分辨率为1毫米且具有高对比度噪声比（CNR）。详细讨论了与扫描仪特定硬件配置相关的典型问题，特别是使用头部发射线圈采集图像时出现的流动伪影以及使用相控阵接收线圈采集图像时头皮强度的增强。理论和实验均表明，通过使用自旋标记和脂肪饱和可以避免这些问题。
