Utilization of an intra-oral diamagnetic passive shim in functional MRI of the inferior frontal cortex
Utilization of an intra-oral diamagnetic passive shim in functional MRI of the inferior frontal cortex
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DOI：
10.1002/mrm.10626
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发表时间：
2003-11-01
影响因子：
3.3
通讯作者：
Jezzard, P
中科院分区：
文献类型：
--
作者：
Wilson, JL;Jezzard, P
由于总磁化率伪影的存在，功能性磁共振成像（fMRI）在人类额叶下皮层（IFC）的研究中被证明存在问题。因此，人们强烈希望采用在保留MRI研究成像参数的同时减轻IFC中易感性伪影的技术。研究表明，使用单一的强抗磁性口腔内被动垫片可显著改善静磁场（B-0）的均匀性，从而减轻IFC内的敏感性伪影。在这项研究中，有关使用口腔内被动垫片的实际问题进行了检查。为了计算口服被动垫片对EPI时间序列时间方差的影响，我们研究了受试者头部运动导致的IFC内B-0不稳定性。这些研究表明，口服被动垫片的加入改善了B-0均匀性和信号稳定性，并增加了对功能激活的敏感性。中华医学杂志，2003,31(5):389 - 394。(C) 2003 Wiley-Liss, Inc。
Due to the presence of gross magnetic susceptibility artifacts, functional MRI (fMRI) has proved problematic in studies of the human inferior frontal cortex (IFC). There is a strong desire, therefore, to employ techniques that mitigate susceptibility artifacts in the IFC while preserving the imaging parameters of an MRI study. It has been shown that the use of a single, strongly diamagnetic, intra-oral passive shim significantly improves the homogeneity of the static magnetic field (B-0) and, as a result, alleviates the susceptibility artifacts within the IFC. In this study, practical issues regarding the use of an intra-oral passive shim are examined. We investigated B-0 instabilities within the IFC resulting from subject head motion in order to calculate the effects of an intra-oral passive shim on the temporal variance of an EPI time series. These studies show that the addition of an intra-oral passive shim improves both B-0 homogeneity and signal stability, and increases sensitivity to functional activation. Magn Reson Med 50:1089-1094, 2003. (C) 2003 Wiley-Liss, Inc.