Biexponential analysis of diffusion-related signal decay in normal human cortical and deep gray matter
Biexponential analysis of diffusion-related signal decay in normal human cortical and deep gray matter
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DOI：
10.1016/j.mri.2008.01.042
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发表时间：
2008-09-01
影响因子：
2.5
通讯作者：
Mulkern, Robert V.
中科院分区：
文献类型：
--
作者：
Maier, Stephan E.;Mulkern, Robert V.
采用高b因子、高空间分辨率和脑脊液信号抑制进行扩散成像，以表征正常皮质灰质和深部灰质（GM）中b因子扩散相关信号衰减的双指数性质。将反转脉冲与线扫描扩散成像序列结合，导致91%的脑脊液信号抑制，允许精确测量皮质GM中的快速扩散系数（1.142 +/- 0.106 μ m（2）/ms），并显示与额叶白色物质（WM）中发现的快速扩散系数（1.1 55 +/- 0.046 μ m（2）/ms）显著相似。在低b因子和高b因子下，GM和WM之间的对比度发生逆转，这是由于皮质GM的慢扩散系数（0.338 +/- 0.027 μ m（2）/ms）明显快于额叶WM的慢扩散系数（0.125 +/- 0.014 μ m（2）/ms）。在其他脑组织结构中观察到GM和WM之间相同的特征扩散差异。相对组分大小在所有研究组织中无显著差异。GM和WM中的细胞结构是根本不同的，并且可以解释GM中的两到三倍高的慢扩散系数。(C)2008年爱思唯尔公司All rights reserved.
Diffusion imaging with high-b factors, high spatial resolution and cerebrospinal fluid signal suppression was performed in order to characterize the biexponential nature of the diffusion-related signal decay with b-factor in normal cortical gray and deep gray matter (GM). Integration of inversion Pulses with a line scan diffusion imaging sequence resulted in 91% cerebrospinal fluid signal Suppression, permitting accurate measurement of the fast diffusion coefficient in cortical GM (1.142 +/- 0.106 mu m(2)/ms) and revealing a marked similarity with that found in frontal white matter (WM) (1.1 55 +/- 0.046 mu m(2)/ms). The reversal of contrast between GM and WM at low vs high b-factors is shown to be due to it significantly faster slow diffusion coefficient in cortical GM (0.338 +/- 0.027 mu m(2)/ms) than in frontal WM (0.125 +/- 0.014 mu m(2)/ms). The same characteristic diffusion differences between GM and WM are observed in other brain tissue structures. The relative component size showed nonsignificant differences among all tissues investigated. Cellular architecture in GM and WM are fundamentally different and may explain the two- to threefold higher slow diffusion coefficient in Gm. (C) 2008 Elsevier Inc. All rights reserved.