QSI and DTI of excised brains of the myelin-deficient rat
QSI and DTI of excised brains of the myelin-deficient rat
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DOI：
10.1016/j.neuroimage.2009.06.019
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发表时间：
2009-10-15
期刊：
影响因子：
5.7
通讯作者：
Cohen, Yoram
中科院分区：
文献类型：
--
作者：
Bar-Shir, Amnon;Duncan, Ian D.;Cohen, Yoram
采用高b值q空间弥散成像（QSI）和常规DTI方法研究21日龄髓磷脂缺乏（md）大鼠及其年龄匹配对照的切除脑MRI弥散特征。从QSI数据中计算三个不同的指标，即位移、概率和峰度，以评估髓鞘对md与对照组脑白质（WM） roi中MR扩散特征的影响。检查的WM roi为胼胝体、外囊和内囊。在所有检查的WM roi中，在所有QSI指数中，md和对照脑之间观察到显着差异。这些差异表明，在WM roi中，轴突周围的髓鞘主要影响扩散受限的成分，表现为低平均位移值和高概率峰度值。这种差异在较长的扩散时间（即δ = 200 ms）中更为明显。常规DTI的b值相对较低(b
High b-value q-space diffusion imaging (QSI) and conventional DTI methodologies were used to study the MRI diffusion characteristics of excised brains of 21-day-old myelin-deficient (md) rats and their age-matched controls. Three different indices were calculated from the QSI data, i.e., Displacement, Probability and Kurtosis, for the purpose of evaluating the effect of the myelin sheaths on the MR diffusion characteristics in white matter (WM) ROIs of the md versus control brains. The examined WM ROIs were the Corpus callosum, the external capsule, and the internal capsule. In all examined WM ROIs, significant differences were observed between the md and control brains for all QSI indices. These differences reveal that myelin sheaths surrounding the axons in WM ROIs mostly affect the component exhibiting restricted diffusion, which is manifested by low mean displacement values and high probability and kurtosis values. Such differences were found to be more pronounced in long diffusion times, i.e., Delta = 200 ms. Conventional DTI performed with relatively low b-values (b