Motion compensated MR imaging system

• US 8,768,034 B2
• Filed: 09/05/2012
• Issued: 07/01/2014
• Est. Priority Date: 03/20/2012
• Status: Active Grant

• Current Assignee: Siemens Healthineers AG (Siemens AG)
• Original Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Inventors: Liu, Kecheng, Zhao, Tiejun
• Primary Examiner(s): GORADIA, SHEFALI DINESH
• Application Number:
  US13/603,679
• Publication Number:
  US 20130251225A1
• Time in Patent Office: 664 Days
• Field of Search: 382/100, 382128-132, 382/275, 600/410
• US Class Current: 382/131
• CPC Class Codes: G01R 33/5673 Gating or triggering based on a physiological signal other than an MR signal, e.g. ECG gating or motion monitoring using optical systems for monitoring the motion of a fiducial marker

Abstract

A method provides motion corrected MR image data in an MR imaging system. The method employs an imaging method for acquiring k-space data of a k-space data array during an imaging scan and the k-space data represents image data of a patient anatomical region. The method acquires k-space data associated with a central region of the k-space data array and subsequently acquires k-space data external to the central region of the k-space data array. The method acquires a motion signal indicating respiratory motion at least during the acquisition of the k-space data external to the central region and compares the motion signal with a predetermined threshold. The method identifies acquired k-space data corresponding to acquisition periods when the motion signal exceeds the threshold and excludes use of the identified acquired k-space data in image reconstruction using the remaining acquired k-space data.

Claims

1. A method for providing motion corrected MR image data in an MR imaging system, comprising the steps of:

employing an imaging method for acquiring k-space data of a k-space data array during an imaging scan,

a) by acquiring k-space data associated with a central region of the k-space data array and

b) subsequently acquiring k-space data external to said central region of the k-space data array, said k-space data representing image data of a patient anatomical region;

acquiring a motion signal indicating respiratory motion at least during the acquisition of said k-space data external to said central region;

comparing said motion signal with a predetermined threshold;

identifying acquired k-space data corresponding to acquisition periods when said motion signal exceeds said threshold; and

excluding use of the identified acquired k-space data in image reconstruction using the remaining acquired k-space data.

2. A method according to claim 1, including the step of

substituting null or blank data for the excluded identified acquired k-space data.

3. A method according to claim 1, wherein

the step of acquiring said k-space data associated with said central region of the k-space data array occurs during a predetermined first period and

the step of subsequently acquiring said k-space data external to said central region of the k-space data array follows said predetermined first period.

4. A method according to claim 3, wherein

said predetermined first period comprises an estimated breathhold period.

5. A method according to claim 4, wherein

said estimated breathhold period comprises 8-15 seconds.

6. A method according to claim 1, wherein

the step of employing said imaging method for acquiring k-space data comprises employing an accelerated imaging method.

7. A method according to claim 6, wherein

said accelerated imaging method comprises a parallel imaging method comprising at least one of, (a) a GRAPPA (Generalized autocalibrating partially parallel acquisitions) method, (b) a Compressed sensing (CS) method, (c) a SENSE (SENSitivity Encoding) method, (d) a SMASH (SMASH (SiMultaneous Acquisition of Spatial Harmonics) method and (e), SPIR-iT, (Iterative Self-Contained Parallel Imaging reconstruction).

8. A method according to claim 1, including the steps of

repairing the excluded identified acquired k-space data and

substituting repaired excluded identified acquired k-space data for said excluded identified acquired k-space data.

9. A method according to claim 1, including the step of

correlating the acquired k-space data associated with said central region with the acquired k-space data external to said central region to identify a portion of said excluded identified acquired k-space data usable for image reconstruction.

10. A method according to claim 9, including the step of

at least one of,

(a) using the identified portion of said excluded identified acquired k-space data for image reconstruction and

(b) repairing the identified portion of said excluded identified acquired k-space data and using the repaired identified portion for image reconstruction.

11. A method according to claim 1, wherein the step of

acquiring said motion signal comprises recording motion data for use in said image reconstruction, said motion data being acquired from at least one of, (a) a sensor of a respiration tracking belt and (b) navigation images.

12. A method for providing motion corrected MR image data in an MR imaging system, comprising the steps of:

employing an imaging method for acquiring k-space data of a k-space data array during an imaging scan,

a) by acquiring k-space data associated with a central region of the k-space data array and

b) subsequently acquiring k-space data external to said central region of the k-space data array, said k-space data representing image data of a patient anatomical region;

acquiring a motion signal indicating respiratory motion at least during the acquisition of said k-space data external to said central region;

comparing said motion signal with a predetermined threshold;

identifying acquired k-space data corresponding to acquisition periods when said motion signal exceeds said threshold;

correlating the acquired k-space data associated with said central region with the acquired k-space data external to said central region to identify a portion of said excluded identified acquired k-space data usable for image reconstruction; and

excluding use of the identified acquired k-space data in image reconstruction using the remaining acquired k-space data.

13. A method according to claim 12, including the step of

at least one of,

(a) using the identified portion of said excluded identified acquired k-space data for image reconstruction and

(b) repairing the identified portion of said excluded identified acquired k-space data and using the repaired identified portion for image reconstruction.

14. A system for providing motion corrected MR image data in an MR imaging system, comprising:

an imaging system for,

employing an imaging method for acquiring k-space data of a k-space data array during an imaging scan,

a) by acquiring k-space data associated with a central region of the k-space data array and

b) subsequently acquiring k-space data external to said central region of the k-space data array, said k-space data representing image data of a patient anatomical region; and

at least one computer for,

acquiring a motion signal indicating respiratory motion at least during the acquisition of said k-space data external to said central region,

comparing said motion signal with a predetermined threshold,

identifying acquired k-space data corresponding to acquisition periods when said motion signal exceeds said threshold, and

excluding use of the identified acquired k-space data in image reconstruction using the remaining acquired k-space data.

15. A system according to claim 14, wherein

said at least one computer substitutes null or blank data for the excluded identified acquired k-space data.

16. A system according to claim 14, wherein

said at least one computer acquires said k-space data associated with said central region of the k-space data array during a predetermined first period and acquires said k-space data external to said central region of the k-space data array following said predetermined first period.

17. A system according to claim 16, wherein

said predetermined first period comprises an estimated breathhold period.

18. A system according to claim 17, wherein

said estimated breathhold period comprises 8-15 seconds.

19. A system according to claim 14, wherein

said imaging system acquires k-space data by employing an accelerated imaging system.

20. A system according to claim 19, wherein

said accelerated imaging system comprises a parallel imaging method comprising at least one of, (a) a GRAPPA (Generalized autocalibrating partially parallel acquisitions) method, (b) a Compressed sensing (CS) method, (c) a SENSE (SENSitivity Encoding) method, (d) a SMASH (SMASH (SiMultaneous Acquisition of Spatial Harmonics) method and (e), SPIR-iT, (Iterative Self-Contained Parallel Imaging reconstruction).

21. A system according to claim 14, wherein

said at least one computer repairs the excluded identified acquired k-space data and substitutes repaired excluded identified acquired k-space data for said excluded identified acquired k-space data.

22. A system according to claim 14, wherein

said at least one computer correlates the acquired k-space data associated with said central region with the acquired k-space data external to said central region to identify a portion of said excluded identified acquired k-space data usable for image reconstruction.

23. A system according to claim 22, wherein

said at least one computer at least one of,

(a) uses the identified portion of said excluded identified acquired k-space data for image reconstruction and

(b) repairs the identified portion of said excluded identified acquired k-space data and using the repaired identified portion for image reconstruction.

24. A system according to claim 23, wherein

said at least one computer repairs the identified portion of said excluded identified acquired k-space data by applying a phase correction to a k-space data element derived from an associated patient respiratory physical displacement.

25. A system according to claim 14, wherein

said at least one computer acquires said motion signal comprises recording motion data for use in said image reconstruction, said motion data being acquired from at least one of, (a) a sensor of a respiration tracking belt and (b) navigation images.