Magnetic resonance imaging with asymmetric radial sampling and compressed-sensing reconstruction

Patent metadata

Field	Value
Publication number	US-9918639-B2
Application number	US-201414531676-A
Country	US
Kind code	B2
Filing date	Nov 3, 2014
Priority date	Nov 7, 2013
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

A method for acquiring cine images using a magnetic resonance imaging (MRI) system includes selecting an asymmetric radial sampling scheme providing an asymmetric view of k-space corresponding to a desired image resolution. Radial k-space data is acquired using the asymmetric radial sampling scheme, wherein slice-orientation of the radial k-space data is continuously modified while acquiring the radial k-space data. A plurality of cine images are reconstructed from the radial k-space data using a compressed-sensing method.

First claim

We claim:

1. A method for acquiring cine images using a magnetic resonance imaging (MRI) system, the method comprising:
selecting an asymmetric radial sampling scheme comprising a plurality of views at different levels of asymmetry providing an asymmetric view of k-space corresponding to a desired image resolution;
acquiring radial k-space data using the asymmetric radial sampling scheme, wherein slice-orientation of the radial k-space data is continuously modified while acquiring the radial k-space data; and
reconstructing a plurality of cine images from the radial k-space data using a compressed-sensing method, wherein the compressed-sensing method enforces L 2 -type data consistency and a L 1 -type non-smooth penalty with respect to the radial k-space data.

2. The method of claim 1 , wherein the asymmetric radial sampling scheme is an interleaved-angle asymmetric radial sampling scheme.

3. The method of claim 2 , wherein the interleaved-angle asymmetric radial sampling scheme comprises:
a full-echo sampling scheme portion to be applied in a center region of k-space; and
a secondary sampling scheme portion to be applied in a remaining area of k-space which excludes the center region of k-space.

4. The method of claim 2 , wherein the interleaved-angle asymmetric radial sampling scheme is a half-echo sampling scheme.

5. The method of claim 2 , wherein the interleaved-angle asymmetric radial sampling scheme distributes the asymmetric view of k-space over 2n.

6. The method of claim 1 , further comprising:
determining a density compensation value corresponding to the asymmetric view of k-space,
wherein the compressed-sensing method applies the density compensation value during the reconstruction of the plurality of cine images.

7. The method of claim 6 , wherein the density compensation value corresponding to the asymmetric view of k-space corresponds to a number of samples to be acquired in the asymmetric view of k-space.

8. The method of claim 1 , wherein the compressed-sensing method incorporates an estimated coil sensitivity map generated in parallel with the reconstruction.

9. A method for acquiring cine images using a magnetic resonance imaging (MRI) system, the method comprising:
selecting an interleaved-angle asymmetric radial sampling scheme comprising a plurality of views at different levels of asymmetry providing an asymmetric view of k-space corresponding to a desired image resolution;
acquiring radial k-space data over a number of interleaves using the interleaved-angle asymmetric radial sampling scheme;
segmenting the radial k-space data into a plurality of overlapping temporal windows based on the number of interleaves; and
reconstructing iteratively a plurality of cine images from the plurality of overlapping temporal windows using a compressed-sensing method, wherein the compressed-sensing method enforces L2-type data consistency and a L1-type non-smooth penalty with respect to the radial k-space data.

10. The method of claim 9 , wherein the radial k-space data is acquired using a Balanced Steady-State Free Precession (bSSFP) sequence.

11. The method of claim 9 , further comprising:
determining a density compensation value corresponding to the asymmetric view of k-space,
wherein the compressed-sensing method applies the density compensation value during the reconstruction of the plurality of cine images.

12. The method of claim 11 , wherein the density compensation value corresponding to the asymmetric view of k-space corresponds to a number of samples to be acquired in the asymmetric view of k-space.

13. The method of claim 9 , wherein the compressed-sensing method incorporates an estimated coil sensitivity map.

14. The method of claim 13 , wherein the method further comprises:
generating the estimated coil sensitivity map in parallel with the reconstruction.

15. A system for acquiring cine images using a magnetic resonance imaging (MRI) system, the system comprising:
an operator interface configured to select an asymmetric radial sampling scheme comprising a plurality of views at different levels of asymmetry providing an asymmetric view of k-space corresponding to a desired image resolution;
a plurality of radio frequency coils configured to acquire radial k-space data using the asymmetric radial sampling scheme, wherein slice-orientation of the radial k-space data is continuously modified while acquiring the radial k-space data; and
a central control computer unit configured to reconstruct a plurality of cine images from the radial k-space data using a compressed-sensing method, wherein the compressed-sensing method enforces L2-type data consistency and a L1-type non-smooth penalty with respect to the radial k-space data.

16. The system of claim 15 , further comprising:
an ECG acquisition system configured to acquire a cardiac timing signal,
wherein the central control computer unit is further configured to divide the radial k-space data in a plurality of overlapping temporal windows based on the cardiac timing signal and reconstruction of the plurality of cine images is based on the plurality of overlapping temporal windows.

Assignees

• Siemens Healthcare Gmbh
• Siemens Healthcard GmbH

Inventors

• Cetingul Hasan Ertan
• Nadar Mariappan S
• Speier Peter
• Schmidt Michaela

Classifications

• A61B5/055

  involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging · CPC title

• G01R33/48

  NMR imaging systems · CPC title

• G01R33/56325

  Cine imaging · CPC title

• A61B5/04

  Human Necessities · mapped topic

• G01R33/546

  Interface between the MR system and the user, e.g. for controlling the operation of the MR system or for the design of pulse sequences · CPC title