Nuclear magnetic resonance systems

摘要

The invention provides an investigation of chemical shift for an element, for example phosphorus, in a region of a body, in one example resonance is preferentially in a line in a slice of the body. Frequency dispersion down the line is produced by a pulsed field having a switched gradient so that the frequency distribution is in steps. This allows a chemical dispersion in each limited region of the line without overlap with adjacent regions. The measured FID signals are Fourier transformed to give a spatial and chemical analysis of the line. Alternatively resonance is excited in a slice and lines selected by a pulsed gradient which gives chemical dispersion as well as spatial dispersion between the lines after Fourier Transformation. This is repeated for many different directions of the pulsed gradient to allow analysis of a chemical line by convolution techniques to give a picture for the slice.