Sampling of the NMR time domain along concentric rings
Sampling of the NMR time domain along concentric rings
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DOI：
10.1016/j.jmr.2006.10.002
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发表时间：
2007-02-01
影响因子：
2.2
通讯作者：
Zhou, Pei
中科院分区：
文献类型：
--
作者：
Coggins, Brian E.;Zhou, Pei
我们提出了一种新的核磁共振时间域采样方法，即采样点在同心环上对齐，我们称之为同心环采样(CRS)。径向采样构成了CRS的一个特例，其中每个环具有相同数量的点和相同的相对方向。我们从理论上推导出，最有效的CRS方法是在半径较大的环上放置更多的点，点数随半径线性增长，这种方法称为线性递增CRS(LCRS)。对于显著欠采样以减少测量时间的情况，还描述了随机LCRS(RLCRS)。提供了对这些方法的理论处理，包括对伪影和敏感性的评估。灵敏度的分析处理也涉及经傅立叶变换处理的径向采样数据的灵敏度。优化的CRS方法被发现在相同的测量时间内产生与笛卡尔采样相同分辨率的无伪影光谱。此外，优化的方法始终产生比径向采样更少和更小的伪影，并且具有与笛卡尔采样相同而比径向采样更好的灵敏度。我们通过数值模拟和三维HNCO实验对该方法进行了验证。(C)2006 Elsevier Inc.保留所有权利。
We present a novel approach to sampling the NMR time domain, whereby the sampling points are aligned on concentric rings, which we term concentric ring sampling (CRS). Radial sampling constitutes a special case of CRS where each ring has the same number of points and the same relative orientation. We derive theoretically that the most efficient CRS approach is to place progressively more points on rings of larger radius, with the number of points growing linearly with the radius, a method that we call linearly increasing CRS (LCRS). For cases of significant undersampling to reduce measurement time, a randomized LCRS (RLCRS) is also described. A theoretical treatment of these approaches is provided, including an assessment of artifacts and sensitivity. The analytical treatment of sensitivity also addresses the sensitivity of radially sampled data processed by Fourier transform. Optimized CRS approaches are found to produce artifact-free spectra of the same resolution as Cartesian sampling, for the same measurement time. Additionally, optimized approaches consistently yield fewer and smaller artifacts than radial sampling, and have a sensitivity equal to Cartesian and better than radial sampling. We demonstrate the method using numerical simulations, as well as a 3D HNCO experiment on protein G B1 domain. (c) 2006 Elsevier Inc. All rights reserved.