Probing short length scales with restricted diffusion in a static gradient using the CPMG sequence
Probing short length scales with restricted diffusion in a static gradient using the CPMG sequence
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DOI：
10.1016/j.jmr.2004.10.006
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发表时间：
2005-01-01
影响因子：
2.2
通讯作者：
Hürlimann, MD
中科院分区：
文献类型：
--
作者：
Zielinski, LJ;Hürlimann, MD
实验验证了用扩散核磁共振提取多孔介质比表面积的方法。与广泛使用的脉冲场梯度（PFG）技术相比，该技术采用受激回波相干路径，我们在这里使用直接Carr-Purcell-Meiboom-Gill（CPMG）路径。即使对于由于场梯度中的扩散而表现出充分衰减的高回波，直接路径的相关标尺长度也由单个脉冲间隔期间的扩散长度固定。因此，直接路径非常适合于探测比传统方法可能的更短的长度尺度。在我们的实验中，在一个低场静态梯度系统中，直接CPMG途径被发现是敏感的结构的数量级小于可访问的刺激回波途径。(C)2004年爱思唯尔公司All rights reserved.
We experimentally verify a method of extracting the surface-to-volume ratio (S/(V)) of porous media with diffusion NMR. In contrast to the widely used pulsed field gradient (PFG) technique, which employs the stimulated echo coherence pathway, we use here the direct Carr-Purcell-Meiboom-Gill (CPMG) path. Even for high echoes, which exhibit ample attenuation due to diffusion in the field gradient, the relevant ruler length for the direct pathway is fixed by the diffusion length during a single inter-pulse spacing. The direct path, therefore, is well suited for probing shorter length scales than is possible with the conventional approach. In our experiments in a low-field static-gradient system, the direct CPMG pathway was found to be sensitive to structure an order of magnitude smaller than accessible with the stimulated-echo pathway. (C) 2004 Elsevier Inc. All rights reserved.