Method and apparatus for measuring and correcting motion effects using navigator echoes
US6791323B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 2002 |
| Grant date | Sep 14, 2004 |
| Priority date | — |
| Expiry date | Oct 16, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/5676
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for detecting displacement of an object using navigator echoes is presented. For motion that is linear in 3D, a linear regression on k-space data is performed by fitting a straight line to the motion-induced phase shift using a k-space weighted least squares minimization to find the displacement. For general motion due to rotation, dilation, and displacement, a rotation angle and dilation scaling factors are determined from the magnitude k-space data by a weighted least squares minimization. A displacement vector is then obtained from the phase data in k-space using a weighted least squares minimization. The weighting factor takes into account that the noise in k-space is inversely proportional to the signal to noise ration. For motion of coronary arteries, the k-space data is acquired in one embodiment using selective volumetric excitation and sampling the resulting excited signal with a trajectory sensitized to the motion of interest.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.