Method for calibrating the amplitude of radiofrequency excitation of a nuclear magnetic resonance imaging apparatus
US4739267A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 4, 1987 |
| Grant date | Apr 19, 1988 |
| Priority date | — |
| Expiry date | May 4, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/341
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Calibration of radiofrequency excitation involves application of two successive pulses of identical waveform and amplitude. The excitations are applied in series of excitations of variable amplitude from one excitation to the next in order to determine the calibrated value of the excitation pulses to be employed by transition of the amplitude of the received signal through a minimum value. It is demonstrated that this procedure prevents the calibration from being impaired by inhomogeneities of the orienting field of the apparatus. Spatial and spectral inhomogeneities of the excitation are also eliminated by applying throughout the calibration a selection gradient to the body under examination. Defects are eliminated by frequency filtering of the detected signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.