Movement-dependent reconstruction of magnetic resonance images

Patent metadata

Field	Value
Publication number	US-10726586-B2
Application number	US-201816029538-A
Country	US
Kind code	B2
Filing date	Jul 6, 2018
Priority date	Jul 7, 2017
Publication date	Jul 28, 2020
Grant date	Jul 28, 2020

Abstract

The invention relates to a method for reconstructing magnetic resonance images, to a magnetic resonance apparatus and to a computer program product. According to the method, measurement data is acquired in an acquisition period. The measurement data is used to determine a motion curve over the acquisition period. In addition, at least one magnetic resonance image is reconstructed. In this process, the acquisition period is separated into a plurality of sub-periods by one or more separating periods and/or separating times in which the motion curve satisfies a defined motion condition, and each magnetic resonance image is reconstructed using the measurement data from at least one sub-period.

First claim

The invention claimed is:

1. A method for reconstructing magnetic resonance images, the method comprising:
acquiring magnetic resonance measurement data in an acquisition period;
determining a motion curve over the acquisition period using the magnetic resonance measurement data;
separating the acquisition period into a plurality of sub-periods using the motion curve and a defined motion condition, wherein the plurality of sub-periods are separated by one or more separating times, one or more separating periods, or the one or more separating times and the one or more separating periods; and
reconstructing at least one magnetic resonance image, wherein each magnetic resonance image of the at least one magnetic resonance image is reconstructed using the magnetic resonance measurement data from at least one sub-period of the plurality of sub-periods.

2. The method of claim 1 , wherein each magnetic resonance image of the at least one magnetic resonance image is reconstructed using the magnetic resonance measurement data from only one sub-period of the plurality of sub-periods.

3. The method as claimed in claim 1 , wherein, on the basis of a defined position condition, each magnetic resonance image of the at least one magnetic resonance image is reconstructed using the magnetic resonance measurement data from only one sub-period of the plurality of sub-periods, or from more than one sub-period of the plurality of sub-periods.

4. The method of claim 1 , wherein the motion curve is filtered according to frequency.

5. The method of claim 1 , wherein the defined motion condition is satisfied by a defined threshold value being exceeded.

6. The method of claim 1 , wherein the reconstruction is performed using magnetic resonance measurement data that was acquired at different times during the at least one sub-period of the plurality of sub-periods.

7. The method of claim 1 , wherein the motion curve is determined using magnetic resonance measurement data from a central k-space region.

8. The method of claim 1 , wherein the magnetic resonance measurement data exhibits a sampling pattern that comprises trajectories passing through a central k-space region.

9. The method as claimed in claim 8 , wherein the trajectories are in the form of spokes.

10. The method as claimed in claim 9 , wherein successive spokes are rotated by a golden angle.

11. The method of claim 1 , wherein the magnetic resonance measurement data comprises subsampling.

12. The method of claim 1 , wherein the respective magnetic resonance image is reconstructed using an iterative reconstruction technique, a view-sharing technique, or a combination thereof.

13. The method of claim 1 , wherein the acquisition of the magnetic resonance measurement data, the reconstruction of the magnetic resonance image, or the acquisition of the magnetic resonance data and the reconstruction of the respective magnetic resonance image are performed using a GRASP technique.

14. The method of claim 1 further comprising:
issuing a warning when the motion curve satisfies a defined warning condition.

15. A magnetic resonance apparatus comprising:
an acquisition unit configured to acquire magnetic resonance measurement data in an acquisition period;
an analysis unit configured to determine a motion curve over the acquisition period using the magnetic resonance measurement data and configured to use the motion curve to separate the acquisition period into a plurality of sub-periods using a defined motion condition, wherein the plurality of sub-periods are separated by one or more separating times, by one or more separating periods, or by the one or more separating times and the one or more separating periods;
a reconstruction unit configured to reconstruct at least one magnetic resonance image and configured to reconstruct each magnetic resonance image of the at least one magnetic resonance image using the measurement data from only one sub-period of the plurality of sub-periods.

16. The magnetic resonance apparatus of claim 15 , wherein each magnetic resonance image of the at least one magnetic resonance image is reconstructed using the measurement data from only one sub-period of the plurality of sub-periods.

17. The magnetic resonance apparatus of claim 15 , wherein, based on a defined position condition, each magnetic resonance image of the at least one magnetic resonance image is reconstructed using the measurement data from only one sub-period of the plurality of sub-periods, or from more than one sub-period of the plurality of sub-periods.

18. The magnetic resonance apparatus of claim 15 , wherein the motion curve is filtered according to frequency.

19. The magnetic resonance apparatus of claim 15 , wherein the motion curve is determined using measurement data from a central k-space region.

20. A non-transitory computer-readable storage medium storing instructions executable by a programmable processing unit of an analysis unit, a reconstruction unit, or the analysis unit and the reconstruction unit, the instructions comprising:
acquiring measurement data in an acquisition period;
determining a motion curve over the acquisition period using the measurement data;
separating the acquisition period into a plurality of sub-periods using the motion curve and a defined motion condition, wherein the plurality of sub-periods are separated by one or more separating times, by one or more separating periods, or by the one or more separating times and the one or more separating periods; and
reconstructing at least one magnetic resonance image, wherein each magnetic resonance image of the at least one magnetic resonance image is reconstructed using the measurement data from at least one sub period of the plurality of sub-periods.

Assignees

• Siemens Healthcare Gmbh

Inventors

• Bauer Simon
• Kartäusch Ralf

Classifications

• G06T12/10 Primary

  Image preprocessing, e.g. calibration, positioning of sources or scatter correction · CPC title

• G01R33/56509 Primary

  due to motion, displacement or flow, e.g. gradient moment nulling (G01R33/567 takes precedence) · CPC title

• G01R33/5676

  Gating or triggering based on an MR signal, e.g. involving one or more navigator echoes for motion monitoring and correction · CPC title

• G01R33/5611

  Parallel magnetic resonance imaging, e.g. sensitivity encoding [SENSE], simultaneous acquisition of spatial harmonics [SMASH], unaliasing by Fourier encoding of the overlaps using the temporal dimension [UNFOLD], k-t-broad-use linear acquisition speed-up technique [k-t-BLAST], k-t-SENSE (structural details of arrays of sub-coils G01R33/3415) · CPC title

• G06T2211/424

  Iterative · CPC title