Gradient reversal technique and its applications to chemical-shift-related NMR imaging

✍ Scribed by H. W. Park; D. J. Kim; Z. H. Cho

• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 525 KB
• Volume: 4
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.1910040604

✦ Synopsis

The chemical-shift effect often degrades slice selectivity thereby degrading the contrast and spatial resolutions in a high-field NMR imaging. We propose a new pulse sequence which can compensate for this chemical-shift effect during slice selection. This technique provides correct slice definition as well as clear separation between water and lipid protons in high-field proton NMR imaging. Particular applications of this technique are 2D imaging with a thin-slice selection and chunk 3D imaging, where correction of the chemical-shift effect in slice selection is important. Another interesting application of the technique is chemical-shift-selective (CHESS) imaging. This technique does not require spectral-selective rfpulses and it takes advantage of the chemical-shift effect during slice selection. The latter is found to be useful for human in vivo chemical-shift imaging in high-field NMR. In this paper, the theoretical derivation of the proposed gradient reversal technique, its applications, and related experimental results are presented.