Magnetic resonance imaging using off-centered spiral trajectories
US6215306A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1999 |
| Grant date | Apr 10, 2001 |
| Priority date | — |
| Expiry date | May 14, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/4833
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The quality of spiral images depends on whether actual k-space sampling points are at their nominal positions. Although newer gradient systems can provide more accurate gradient waveforms, timing mis-registration between data acquisition and gradient systems can significantly distort the positions of samples. Even after the timing of data acquisition is tuned, minor residual errors can still cause shading artifacts which are problematic for quantitative MRI applications, such as the phase-contrast method. Although ideally measuring the actual k-space trajectory can correct for the timing errors, it requires additional data acquisition and scan time. The present invention employs off-centered spiral trajectories which are more robust against timing errors and applies them to the phase-contrast method. The new trajectories turn shading artifacts into a slowly-varying linear phase in reconstructed images without affecting the magnitude of images.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.