THE K-TRAJECTORY FORMULATION OF THE NMR IMAGING PROCESS WITH APPLICATIONS IN ANALYSIS AND SYNTHESIS OF IMAGING METHODS
THE K-TRAJECTORY FORMULATION OF THE NMR IMAGING PROCESS WITH APPLICATIONS IN ANALYSIS AND SYNTHESIS OF IMAGING METHODS
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DOI：
10.1118/1.595331
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发表时间：
1983-01-01
期刊：
影响因子：
3.8
通讯作者：
TWIEG, DB
中科院分区：
文献类型：
--
作者：
TWIEG, DB
对于大量方法，核磁共振（NMR）成像的基本操作可以表述为在傅立叶空间-频率域中对对象分布进行采样，然后处理数字化数据（通常简单地通过傅立叶变换）以产生数字图像。在这些方法中，包括从投影重建、傅立叶成像、自旋-扭曲成像和回波平面成像，可控梯度场确定空间-频率域中的点，这些点在数据采集期间的任何给定时间被采样（自由感应衰减或FID）。所得到的采样点的轨迹（thektrajectory）的详细时间依赖性确定了测量每个空间频率处的图像信息的相对权重和准确度，建立了给定成像方法可实现的图像质量的理论限制。我们在这里证明，这些考虑因素可用于比较NMR成像方法的理论能力，并获得新的成像方法与最佳的理论成像性能。
The fundamental operations of nuclear magnetic resonance (NMR) imaging can be formulated, for a large number of methods, as sampling the object distribution in the Fourier spatial‐frequency domain, followed by processing the digitized data (often simply by Fourier transformation) to produce a digital image. In these methods, which include reconstruction from projections, Fourier imaging, spin‐warp imaging, and echo‐planar imaging, controllable gradient fields determine the points in the spatial‐frequency domain which are sampled at any given time during the acquisition of data (the free induction decay, or FID). The detailed time dependence of the resulting trajectory of sample points (thektrajectory) determines the relative weight and accuracy with which image information at each spatial frequency is measured, establishing theoretical limitations on image quality achievable with a given imaging method. We demonstrate here that these considerations may be used to compare the theoretical capabilities of NMR imaging methods, and to derive new imaging methods with optimal theoretical imaging properties.