Multi-dimensional selective NMR excitation with a single RF pulse
US4812760A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 1987 |
| Grant date | Mar 14, 1989 |
| Priority date | — |
| Expiry date | Jul 27, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/446
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A single rotating NMR .pi. pulse provides simultaneous spatially-selective inversion or spin-echo refocussing of nuclear pins in two orthogonal dimensions. The two-dimensional spatially-selective pulse utilizes a single RF pulse, with either a square of an amplitude-modulated or a frequency-modulated envelope, and applied in the presence of an amplitude-modulated magnetic field gradient which reorients through the desired dimensions in which selection is desired while the RF pulse is present. These rotating, or ".rho.", pulses are useful for reduction of aliasing signal artifacts is restricted field-of-view high-resolution NMR imaging and, when combined with one-dimensional-localized chemical shift spectroscpoy techniques (such as those employing surface detection coils) is especially useful for the production of three-dimensionally localized NMR spectra. Substantial suppression of undesirable residual excited signals, arising from outside the desired two-dimensional spatially selected region, can be obtained by simulated annealing optimization of both the RF and magnetic field gradient amplitude portions of the .rho. pulse and/or by use of surface coil detection. The location of t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.