Method of analysing the structure and characteristics of an object
US4654594A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 14, 1983 |
| Grant date | Mar 31, 1987 |
| Priority date | — |
| Expiry date | Dec 14, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/4835
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention relates to a method of recovering nuclear spin or NMR information about a target, such as a human body placed in at least substantially homogenous magnetic field, a desired part of the target being excited by means of a radiofrequency magnetic field which preferably deviates nuclear magnetization through 90.degree., a so-called spin echo is generated by utilizing a second excitation of the target volume which preferably deviates nuclear magnetization through 180.degree., said spin echo is recorded and said excitation sequence is repeated. At least one magnetic field is applied to the target in a manner that the duration and/or amplitude of said magnetic field gradient are varied between various repetitions, so that the difference between the absolute values of time integral of a value following said 180.degree. pulse and a value preceding said 180.degree. pulse of said magnetic field gradient obtains a different value. This way, the use of bipolar current sources is avoided. The invention is well adaptable to recovering information quickly especially about a plurality of image planes from a three-dimensional target.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.