Sampling strategies for sparse magnetic resonance image reconstruction

Patent metadata

Field	Value
Publication number	US-9689947-B2
Application number	US-201414515714-A
Country	US
Kind code	B2
Filing date	Oct 16, 2014
Priority date	Oct 21, 2013
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

A computer-implemented method of selecting a Magnetic Resonance Imaging (MRI) sampling strategy includes selecting a base variable-density sampling pattern and determining a scan time associated with the base variable-density sampling pattern. A modified variable-density sampling pattern is created by modifying one or more parameters of the base variable-density sampling pattern to maximize a sampled k-space area without increasing the scan time. Next, a scan is performed on an object of interest using the modified variable-density sampling pattern to obtain a sparse MRI dataset. Then a sparse reconstruction process is applied to the sparse MRI dataset to yield an image of the object of interest.

First claim

We claim:

1. A computer-implemented method of selecting a Magnetic Resonance Imaging (MRI) sampling strategy, the method comprising:
selecting a base variable-density sampling pattern;
determining a scan time associated with the base variable-density sampling pattern;
creating a modified variable-density sampling pattern by modifying one or more parameters of the base variable-density sampling pattern to maximize a sampled k-space area without increasing the scan time;
performing a scan on an object of interest using the modified variable-density sampling pattern to obtain a sparse MRI dataset; and
applying a sparse reconstruction process to the sparse MRI dataset to yield an image of the object of interest.

2. The method of claim 1 , further comprising:
modifying the one or more parameters of the base variable-density sampling pattern during creation of the modified variable-density sampling pattern such that sampling density of a k-space center region is maintained above a threshold value.

3. The method of claim 1 , wherein the base variable-density sampling pattern is a spiral pattern.

4. The method of claim 3 , wherein the spiral pattern is a spiral phyllotaxis pattern.

5. The method of claim 3 , wherein modification of the base variable-density sampling pattern to create the modified variable-density sampling pattern comprises:
modifying the one or more parameters to increase a maximum k-space radius of the spiral pattern in at least one of a frequency direction and a phase direction.

6. The method of claim 1 , wherein maximizing the sampled k-space area expands k-space coverage of the modified variable-density sampling pattern along a frequency axis.

7. The method of claim 1 , wherein maximizing the sampled k-space area comprises expanding k-space coverage of the modified variable-density sampling pattern along a phase axis.

8. The method of claim 1 , wherein the base variable-density sampling pattern and the modified variable-density sampling pattern correspond to an identical number of sampling points.

9. The method of claim 1 , wherein the base variable-density sampling pattern is selected from a plurality of variable density sampling patterns based on a distinctive scan time value associated with each respective base variable-density sampling patterns.

10. An article of manufacture for selecting a Magnetic Resonance Imaging (MRI) sampling strategy, the article of manufacture comprising a non-transitory, tangible computer-readable medium holding computer-executable instructions for performing a method comprising:
receiving a selection of a base variable-density sampling pattern;
determining a scan time associated with the base variable-density sampling pattern;
creating a modified variable-density sampling pattern by modifying one or more parameters of the base variable-density sampling pattern to maximize a sampled k-space area without increasing the scan time;
sending one or more instructions to an MRI device to acquire one or more images of an object of interest using the modified variable-density sampling pattern and a sparse reconstruction process; and
receiving the one or more images of the object of interest in response to the one or more instructions.

11. The article of manufacture of claim 10 , wherein the method further comprises:
modifying the one or more parameters of the base variable-density sampling pattern during creation of the modified variable-density sampling pattern such that sampling density of a k-space center region is maintained above a threshold value.

12. The article of manufacture of claim 10 , wherein the base variable-density sampling pattern is a spiral pattern.

13. The article of manufacture of claim 12 , wherein the spiral pattern is a spiral phyllotaxis pattern.

14. The article of manufacture of claim 12 , wherein modification of the base variable-density sampling pattern to create the modified variable-density sampling pattern comprises:
modifying the one or more parameters to increase a maximum k-space radius of the spiral pattern in at least one of a frequency direction and a phase direction.

15. The article of manufacture of claim 10 , wherein maximizing the sampled k-space area expands k-space coverage of the modified variable-density sampling pattern along a frequency axis.

16. The article of manufacture of claim 10 , wherein maximizing the sampled k-space area comprises expanding k-space coverage of the modified variable-density sampling pattern along a phase axis.

17. The article of manufacture of claim 10 , wherein the base variable-density sampling pattern and the modified variable-density sampling pattern correspond to an identical number of sampling points.

18. The article of manufacture of claim 10 , wherein the base variable-density sampling pattern is selected from a plurality of variable density sampling patterns based on a distinctive scan time value associated with each respective base variable-density sampling patterns.

19. A system for selecting a Magnetic Resonance Imaging (MRI) sampling strategy, the system comprising:
a plurality of radio frequency coils;
a plurality of gradient coils;
an operator interface configured to:
receive a selection of a base variable-density sampling pattern,
determine a scan time associated with the base variable-density sampling pattern,
create a modified variable-density sampling pattern by modifying one or more parameters of the base variable-density sampling pattern to maximize a sampled k-space area without increasing the scan time; and

a central control computer unit configured to utilize the plurality of radio frequency coils and the plurality of gradient coils to perform a scan of an object of interest using the modified variable-density sampling pattern.

20. The system of claim 19 , wherein the central control computer unit is further configured to:
acquire a sparse MRI dataset in response to the scan, and
apply a sparse reconstruction process to the sparse MRI dataset to yield an image of the object of interest.

Assignees

• Siemens Healthcare Gmbh

Inventors

• Wang Qiu
• Zenge Michael
• Mueller Edgar
• Nadar Mariappan S

Classifications

• G01R33/5611 Primary

  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

• G01R33/4826

  in three dimensions · CPC title