Estimation of Cell Membrane Permeability and Intracellular Diffusion Coefficient of Human Gray Matter
Estimation of Cell Membrane Permeability and Intracellular Diffusion Coefficient of Human Gray Matter
复制标题
DOI：
10.2463/mrms.8.1
复制
发表时间：
2009-01-01
影响因子：
3
通讯作者：
Ohtomo, Kuni
中科院分区：
文献类型：
--
作者：
Imae, Toshikazu;Shinohara, Hiroyuki;Ohtomo, Kuni
扩散加权成像（DWI）的信号强度对细胞内和细胞外的水扩散系数和细胞膜渗透性敏感。我们应用了之前论文中提出的方法，无创地估计了 3 名正常志愿者的正常人脑（灰质）的膜通透性和细胞内扩散系数。我们使用 1.5 特斯拉磁共振 (MR) 成像系统从理论上比较了预测信号和实验结果。我们使用平面回波成像 (EPI) 序列获取图像，并在 3 个方向上应用运动探测梯度 (MPG) 脉冲。我们定期使用有限差分法对膜渗透性和细胞内扩散系数的各种组合进行数值模拟。通过最小化实验获得的信号与数值模拟信号之间的差异，我们可以估计人脑的膜渗透性（76 +/- 9 mm(2)/s mu m）和细胞内扩散系数（1.0 +/- 0.0 mm(2)/s）。估计的膜通透性是诊断灰质疾病的标准值。
The signal intensity of diffusion-weighted imaging (DWI) is sensitive to the intra- and extracellular diffusion coefficient of water and cell membrane permeability. We applied a method we proposed in previous papers to estimate noninvasively the membrane permeability and intracellular diffusion coefficient of normal human brain (gray matter) in 3 normal volunteers. We theoretically compared predicted signals and experiment results using a 1.5-tesla magnetic resonance (MR) imaging system. We acquired images using an echo planar imaging (EPI) sequence, applying motion-probing gradient (MPG) pulses in 3 directions. We periodically performed numerical simulations for various combinations of membrane permeability and intracellular diffusion coefficients using the finite-difference method. By minimizing the difference between signals obtained experimentally and those from numerical simulation, we could estimate membrane permeability (76 +/- 9 mm(2)/s mu m) and intracellular diffusion coefficient (1.0 +/- 0.0 mm(2)/s) for the human brain. The estimated membrane permeability was the criterion value for diagnosing disease in gray matter.