Change of the cerebrospinal fluid volume during brain activation investigated by T1ρ-weighted fMRI
Change of the cerebrospinal fluid volume during brain activation investigated by T1ρ-weighted fMRI
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DOI：
10.1016/j.neuroimage.2010.03.047
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发表时间：
2010-07-15
期刊：
影响因子：
5.7
通讯作者：
Kim, Seong-Gi
中科院分区：
文献类型：
--
作者：
Jin, Tao;Kim, Seong-Gi
磁共振成像中的体素通常包含组织和脑脊液(CSF)。在功能刺激期间，这些不同水室的体积分数可能会改变。为了直接成像脑脊液体积分数并测量其功能变化，我们使用了旋转框架纵向弛豫时间(T-1 Rho)加权MRI技术。在9.4T，自旋锁定频率接近500 Hz时，组织水和脑脊液的T-1Rho分别约为48ms和450ms。因此，当施加长的自旋锁定时间(例如，200ms)时，实质信号变得可以忽略，仅留下CSF信号。对异氟醚麻醉猫(n=6)的基础脑脊液体积分数(V-CSF)及其视觉刺激引起的变化进行了定位。在自旋锁定时间为200ms和300ms的T-1Rho加权fMRI中，均观察到幅度相似的负变化，表明V-CSF的下降是主要贡献因素。在含有视皮层和脑脊液隔室的体素区域，平均基线V-CSF为24.6+/-2%，平均脑脊液体积分数变化(Delta V-CSF/V-CSF)为-2.45+/-0.6%，绝对脑脊液体积分数变化(Delta V-CSF)为-0.6+/-0.15%。像素级基线V-CSF与Delta V-CSF/V-CSF呈负相关，这可以用体素间相似的Delta V-CSF来解释。我们的结果表明，脑脊液体积分数的功能性减少可能对fMRI信号有贡献，特别是当组织信号在某些实验技术或参数下与脑脊液相比显著降低时。由爱思唯尔公司出版。
A voxel in MRI often contains tissue as well as cerebrospinal fluid (CSF). During functional stimulation, volume fractions of these different water compartments may change. To directly image the CSF volume fraction and measure its functional change, we utilized a rotating-frame longitudinal relaxation time (T-1 rho)-weighted MRI technique. At 9.4 T with a spin-locking frequency of similar to 500 Hz, T-1 rho, of tissue water and CSF are about 48 and 450 ms, respectively. Therefore, the parenchyma signal becomes negligible when a long spin-locking time (e.g., 200 ms) is applied, leaving only the CSF signal. Baseline CSF volume fraction (V-csf) and its change induced by visual stimulation were mapped in isoflurane-anesthetized cats (n = 6). In both T-1 rho-weighted fMRI with spin locking times of 200 and 300 ms, negative changes with similar magnitudes were observed, indicating that a decrease in V-csf is a dominant contributor. In the region with voxels containing the visual cortex and CSF compartments, an average baseline V-csf was 24.6 +/- 2%, an average CSF volume fraction change (Delta V-csf/V-csf) was -2.45 +/- 0.6%, and an absolute change in CSF volume fraction (Delta V-csf) was -0.6 +/- 0.15%. A negative correlation was observed between pixel-wise baseline V-csf and Delta V-csf/V-csf, which can be explained by similar Delta V-csf among voxels. Our results suggest that the functional reduction of CSF volume fraction could contribute to fMRI signals, especially when the tissue signal is significantly reduced as compared to the CSF with certain experimental techniques or parameters. Published by Elsevier Inc.