MOVEMENT-DEPENDENT RECONSTRUCTION OF MAGNETIC RESONANCE IMAGES

• US 20190012813A1
• Filed: 07/06/2018
• Published: 01/10/2019
• Est. Priority Date: 07/07/2017
• Status: Active Grant

• Current Assignee: Siemens Healthineers AG (Siemens AG)
• Original Assignee: Siemens Healthcare GMBH (Siemens AG)
• Inventors: Bauer, Simon, Kartausch, Ralf
• Granted Patent: US 10,726,586 B2
• Time in Patent Office: Days
• CPC Class Codes: G01R 33/4824 using a non-Cartesian trajectory
• CPC Class Codes: G01R 33/5611 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 Class Codes: G01R 33/56509 due to motion, displacement or flow, e.g. gradient moment nulling G01R33/567 takes precedence
• CPC Class Codes: G01R 33/5676 Gating or triggering based on an MR signal, e.g. involving one or more navigator echoes for motion monitoring and correction
• CPC Class Codes: G06T 11/005 Specific pre-processing for tomographic reconstruction, e.g. calibration, source positioning, rebinning, scatter correction, retrospective gating
• CPC Class Codes: G06T 2211/424 Iterative

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.

Claims

1. A method for reconstructing magnetic resonance images, which method comprises the following steps:

acquiring measurement data in an acquisition period;

using the measurement data to determine a motion curve over the acquisition period;

separating the acquisition period into a plurality of sub-periods by one or more separating times and/or separating periods using the motion curve by means of a defined motion condition;

reconstructing at least one magnetic resonance image,

wherein each magnetic resonance image is reconstructed using the measurement data from at least one of the plurality of sub-periods.

2. The method as claimed in one of the preceding claims,

wherein each magnetic resonance image is reconstructed using the measurement data from only one 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 is reconstructed using the measurement data from only one, or from a plurality, of the plurality of sub-periods.

4. The method as claimed in one of the preceding claims,

wherein the motion curve is filtered according to frequency.

5. The method as claimed in one of the preceding claims,

wherein the defined motion condition is satisfied by a defined threshold value being exceeded.

6. The method as claimed in one of the preceding claims,

wherein the reconstruction is performed using measurement data that was acquired at different times of the particular sub-period.

7. The method as claimed in one of the preceding claims,

wherein the motion curve is determined using measurement data from a central k-space region.

8. The method as claimed in one of the preceding claims,

wherein the 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 as claimed in one of the preceding claims,

wherein the measurement data comprises subsampling.

12. The method as claimed in one of the preceding claims,

wherein the magnetic resonance image is reconstructed using an iterative reconstruction technique and/or a view-sharing technique.

13. The method as claimed in one of the preceding claims,

wherein the acquisition of the measurement data and/or the reconstruction of the magnetic resonance image are performed using a GRASP technique.

14. The method as claimed in one of the preceding claims,

wherein a warning is issued if the motion curve satisfies a defined warning condition.

16. The magnetic resonance apparatus, which is designed to implement a method as claimed in one of claims 2 to 14.

17. A computer program product, which comprises a program and can be loaded directly into a memory of a programmable processing unit of an analysis unit and/or reconstruction unit, and has program means in order to perform a method as claimed in one of claims 1 to 14 when the program is executed in the processing unit of the analysis unit and/or reconstruction unit.

15. A magnetic resonance apparatus comprising

an acquisition unit for acquiring measurement data in an acquisition period;

an analysis unit for using the measurement data to determine a motion curve over the acquisition period;

a reconstruction unit for reconstructing at least one magnetic resonance image,

wherein the analysis unit is designed to use the motion curve to separate the acquisition period into a plurality of sub-periods by one or more separating times and/or separating periods by means of a defined motion condition,

wherein the reconstruction unit is designed to reconstruct each magnetic resonance image using the measurement data from only one sub-period.