Optimizing the detection of white matter fMRI using asymmetric spin echo spiral
Optimizing the detection of white matter fMRI using asymmetric spin echo spiral
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DOI：
10.1016/j.neuroimage.2008.11.005
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发表时间：
2009-03-01
期刊：
影响因子：
5.7
通讯作者：
D'Arcy, Ryan C. N.
中科院分区：
文献类型：
--
作者：
Gawryluk, Jodie R.;Brewer, Kimberly D.;D'Arcy, Ryan C. N.
大多数功能磁共振成像(FMRI)研究将焦点限制在灰质区域，因为相对于白质，灰质组织是高度灌注的。然而，越来越多的研究报告说，脑白质中有fMRI的激活。目前的研究有两个目标：1)评估是否有可能检测到白质fMRI的激活；2)确定某些MRI对比剂机制是否对白质激活更敏感(即，粗略对比与T-2加权)。数据来自4T磁共振成像，采用不对称自旋回波螺旋序列(ASE螺旋)。该技术收集了三幅图像，采用等对比度加权和增加T-2加权。大脑半球间的转移任务被用来诱导胼胝体的激活。分别对平均ASE螺旋数据和每幅图像的脑白质功能磁共振活动进行检测。在所有受试者中，以及在群体分析中，都存在胼胝体激活。分析表明，增加T-2对比度提高了灵敏度，以信号变化百分比衡量。结果表明，在功能磁共振成像中可以检测到白质的激活，ASE螺旋对这种激活的敏感性随着T-2加权的增加而增加。这一发现为脑白质功能磁共振成像的研究提供了进一步的支持。(C)2008 Elsevier Inc.保留所有权利。
The majority of functional magnetic resonance imaging (fMRI) studies restrict their focus to gray matter regions because this tissue is highly perfused relative to white matter. However, an increasing number of studies are reporting fMRI activation in white matter. The current study had two objectives: 1) to evaluate whether it is possible to detect white matter fMRI activation and 2) to determine whether certain MRI contrast mechanisms are more sensitive to white matter activation (i.e., BOLD contrast-versus T-2-weighting). Data were acquired from a 4 T MRI using an asymmetric spin echo spiral sequence (ASE spiral). This technique collected three images with equal BOLD contrast weighting and increasing T-2-weighting. An interhemispheric transfer task was used to elicit activation in the corpus callosum. White matter fMRI activation was examined for the averaged ASE spiral data and for each image separately. Callosal activation was present in all subjects as well as in the group analysis. Analyses revealed that increasing T-2 contrast improved sensitivity as measured by percent signal change. The results suggest that it is possible to detect white matter activation in fMRI and that ASE spiral showed increasing sensitivity to this activation as a function of T-2-weighting. The findings provide further support for the investigation of white matter fMRI. (C) 2008 Elsevier Inc. All rights reserved.