Method and apparatus for imaging instruments during interventional MRI using asymmetric spin echo sequences
US6332088A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1998 |
| Grant date | Dec 18, 2001 |
| Priority date | — |
| Expiry date | Nov 12, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/56308
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An asymmetric spin-echo (ASE) sequence having a variable asymmetry (.DELTA.TE) with respect to the RF pulse is used for imaging paramagnetic, diamagnetic or ferromagnetic instruments within tissues during interventional MRI procedures. The degree of asymmetry introduced determines an apparent size of the imaged instrument. In one embodiment of the invention, the amount of asymmetry is varied as a function of the phase encoding gradient steps. In this manner, the sequence is made sensitive to local gradients in the magnetic field but left insensitive to large scale variations such as those introduced by main magnetic field inhomogeneities.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.