Depth and refocusing pulses for use with inhomogeneous radiofrequency coils in nuclear magnetic resonance spectroscopy
US4742303A · kind A · utility
Inventor
Key dates
| Filing date | Sep 13, 1985 |
| Grant date | May 3, 1988 |
| Priority date | — |
| Expiry date | Sep 13, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/465
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a pulsed nuclear magnetic resonance method of analysis, a series of phase cycled radiofrequency pulses of the form 2.theta.; .theta.[.+-.x]; (2.theta.[.+-.,.+-.y]).sub.4, called a depth pulse scheme, may be applied using an irradiation coil which provides an inhomogeneous radiofrequency field across the sample volume, so that signals may only be detected from sample regions where the pulse angle .theta. is close to m.pi./2, where m is an odd integer. However, signals from regions where .theta.=3.pi./2 or 5.pi./2, if such regions exist, can be eliminated by varying some of the pulses from their ideal .theta. of 2.theta. values. The sample discrimination afforded by means of these pulse schemes may be improved by using static or pulsed magnetic field gradients or by using more than one radiofrequency coil.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.