Center for Biomedical Imaging, New York University School of Medicine, New York, NY 10016, USA.
J Magn Reson. 2011 May;210(1):141-5. doi: 10.1016/j.jmr.2011.02.011. Epub 2011 Feb 16.
Restrictions to diffusion result in the dispersion of the bulk diffusion coefficient. We derive the exact universal high-frequency behavior of the diffusion coefficient in terms of the surface-to-volume ratio of the restrictions. This frequency dependence can be applied to quantify structure of complex samples with NMR using oscillating field gradients and static-gradient CPMG. We also demonstrate the inter-relations between different equivalent diffusion metrics, and describe how to calculate the effect of restrictions for arbitrary gradient waveforms.
扩散限制导致体扩散系数的分散。我们根据限制的表面积与体积比推导出扩散系数的精确通用高频行为。这种频率依赖性可用于使用振荡磁场梯度和静态梯度 CPMG 通过 NMR 定量分析复杂样品的结构。我们还展示了不同等效扩散度量之间的相互关系，并描述了如何计算任意梯度波形的限制影响。
