Halse Meghan E, Callaghan Paul T
MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6001, New Zealand.
J Magn Reson. 2007 Mar;185(1):130-7. doi: 10.1016/j.jmr.2006.12.005. Epub 2006 Dec 28.
We present a novel method for obtaining high resolution NMR spectra in the presence of grossly inhomogeneous magnetic fields, such as those encountered in one-sided access NMR. Our method combines the well-known principle of reference deconvolution with NMR imaging in order to resolve spectral features with frequency resolution orders of magnitude smaller than the prevailing line-broadening due to field inhomogeneity. We demonstrate that, in cases of inhomogeneous field line-broadening more than an order of magnitude larger than the spectral features to be resolved, rather than performing reference deconvolution on the sample as a whole, it is more favourable in terms of SNR to divide the target region of a sample into smaller sub-regions, by means of chemical shift imaging, and then to perform reference deconvolution on the individual sub-region spectra, finally summing the results In this way, significant resolution enhancements can be obtained in the presence of severe magnetic field inhomogeneity without an unacceptable loss in SNR.
我们提出了一种在存在严重不均匀磁场的情况下获取高分辨率核磁共振谱的新方法，例如在单侧进样核磁共振中遇到的磁场。我们的方法将著名的参考去卷积原理与核磁共振成像相结合，以解析频率分辨率比由于磁场不均匀性导致的主要线宽小几个数量级的光谱特征。我们证明，在不均匀场线宽比要解析的光谱特征大一个数量级以上的情况下，不是对整个样品进行参考去卷积，而是通过化学位移成像将样品的目标区域划分为较小的子区域，然后对各个子区域的光谱进行参考去卷积，最后将结果相加。这样，在存在严重磁场不均匀性的情况下，可以在不损失不可接受的信噪比的情况下显著提高分辨率。
