Christen Thomas, Jahanian Hesamoddin, Ni Wendy W, Qiu Deqiang, Moseley Michael E, Zaharchuk Greg
Department of Radiology, Stanford University, Stanford, California, USA.
J Magn Reson Imaging. 2015 Feb;41(2):424-30. doi: 10.1002/jmri.24558. Epub 2014 Jan 13.
To investigate if delays in resting-state spontaneous fluctuations of the BOLD (sfBOLD) signal can be used to create maps similar to time-to-maximum of the residue function (Tmax) in Moyamoya patients and to determine whether sfBOLD delays affect the results of brain connectivity mapping.
Ten patients were scanned at 3 Tesla using a gradient-echo echo planar imaging sequence for sfBOLD imaging. Cross correlation analysis was performed between each brain voxel signal and a reference signal comprised of either the superior sagittal sinus (SSS) or whole brain (WB) average time course. sfBOLD delay maps were created based on the time shift necessary to maximize the correlation coefficient, and compared with dynamic susceptibility contrast Tmax maps. Standard and time-shifted resting-state BOLD connectivity analyses of the default mode network were compared.
Good linear correlations were found between sfBOLD delays and Tmax using the SSS as reference (r(2) = 0.8, slope = 1.4, intercept = -4.6) or WB (r(2) = 0.7, slope = 0.8, intercept = -3.2). New nodes of connectivity were found in delayed regions when accounting for delays in the analysis.
Resting-state sfBOLD imaging can create delay maps similar to Tmax maps without the use of contrast agents in Moyamoya patients. Accounting for these delays may affect the results of functional connectivity maps.
研究静息态脑血氧水平依赖性功能磁共振成像（sfBOLD）信号的自发波动延迟是否可用于生成类似于烟雾病患者残差函数最大时间（Tmax）的图谱，并确定sfBOLD延迟是否会影响脑连接图谱的结果。
对10例患者采用梯度回波平面回波成像序列在3特斯拉场强下进行sfBOLD成像扫描。对每个脑区体素信号与由上矢状窦（SSS）或全脑（WB）平均时间进程组成的参考信号进行互相关分析。基于使相关系数最大化所需的时间偏移创建sfBOLD延迟图谱，并与动态磁敏感对比Tmax图谱进行比较。比较默认模式网络的标准静息态BOLD连接分析和时间偏移静息态BOLD连接分析。
以SSS为参考时，sfBOLD延迟与Tmax之间存在良好的线性相关性（r(2) = 0.8，斜率 = 1.4，截距 = -4.6）；以WB为参考时，两者相关性也良好（r(2) = 0.7，斜率 = 0.8，截距 = -3.2）。在分析中考虑延迟时，在延迟区域发现了新的连接节点。
静息态sfBOLD成像可在不使用造影剂的情况下为烟雾病患者生成类似于Tmax图谱的延迟图谱。考虑这些延迟可能会影响功能连接图谱的结果。
