Magnetic resonance imaging system using sub-volumes and magnetic resonance imaging method using sub-volumes

Patent metadata

Field	Value
Publication number	US-9958523-B2
Application number	US-201314079199-A
Country	US
Kind code	B2
Filing date	Nov 13, 2013
Priority date	Nov 14, 2012
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

A magnetic resonance imaging (MRI) method includes: applying radio-frequency (RF) pulses comprising a plurality of frequency components and a selection gradient to a subject to simultaneously excite a plurality of sub-volumes in each of a plurality of groups, wherein a plurality of sub-volumes making up a volume of the subject are divided into the plurality of groups so that any neighboring sub-volumes belong to different groups; performing three-dimensional (3D) encoding on each of the excited sub-volumes using a plurality of encoding methods; acquiring magnetic resonance signals from the encoded sub-volumes; and reconstructing the acquired magnetic resonance signals into image data corresponding to each of the encoded sub-volumes.

First claim

What is claimed is:

1. A magnetic resonance imaging (MRI) method comprising:
simultaneously exciting a first plurality of sub-volumes of a subject, the excited first sub-volumes being separated from one another by second sub-volumes of the subject that are not excited at a same time as the excited first sub-volumes, the second sub-volumes being excited at one or more other times from the first excited sub-volumes;
performing three-dimensional (3D) encoding on each of the excited first sub-volumes using a plurality of encoding methods;
acquiring magnetic resonance image signals from the encoded first sub-volumes; and
reconstructing the acquired magnetic resonance signals into image data corresponding to each of the encoded first sub-volumes.

2. The method of claim 1 , further comprising performing a repeating of the exciting, encoding, acquiring, and reconstructing on another plurality of sub-volumes of the subject selected from the second sub-volumes until the performing the exciting, encoding, acquiring, and reconstructing have been performed on all of the sub-volumes of the subject.

3. The method of claim 1 , wherein the encoding methods comprise a plurality of encoding methods having different trajectories in different respective dimensions.

4. The method of claim 1 , wherein the encoding methods comprise a plurality of encoding methods having different sensitivities to a motion of the subject.

5. The method of claim 1 , wherein the encoding methods comprise a plurality of encoding methods producing k-space data having a plurality of different distributions.

6. A magnetic resonance imaging (MRI) method comprising:
applying radio-frequency (RF) pulses comprising a plurality of frequency components and a selection gradient to a subject to simultaneously excite a plurality of sub-volumes in each of a plurality of groups, wherein a plurality of sub-volumes making up a volume of the subject are divided into the plurality of groups so that any neighboring sub-volumes belong to different groups;
performing three-dimensional (3D) encoding on each of the excited sub-volumes using a plurality of encoding methods;
acquiring magnetic resonance signals from the encoded sub-volumes; and
reconstructing the acquired magnetic resonance signals into image data corresponding to each of the encoded sub-volumes.

7. The method of claim 6 , wherein the performing of the 3D encoding comprises:
performing a first encoding method in a first direction and a second direction on each of the excited sub-volumes; and
performing a second encoding method in a third direction on each of the excited sub-volumes.

8. The method of claim 7 , wherein the first encoding method comprises radial encoding or spiral encoding; and
the second encoding method comprises Cartesian encoding.

9. The method of claim 6 , wherein the plurality of groups comprise a first group through an N-th group, the plurality of sub-volumes making up the volume of the subject are sequentially and cyclically distributed to the first group through the N-th group, and N is an integer greater than or equal to 2.

10. The method of claim 6 , wherein the reconstructing of the acquired magnetic resonance signals comprises reconstructing the acquired magnetic resonance signals into the image data corresponding to each of the encoded sub-volumes using a parallel imaging algorithm that takes into consideration channel information of multi-channel receiver coils configured to acquire the magnetic resonance signals.

11. The method of claim 6 , further comprising performing the applying of the RF pulses and the selection gradient to the subject, the performing of the 3D encoding on each of the excited sub-volumes, the acquiring of the magnetic resonance signals from the encoded sub-volumes, and the reconstructing of the acquired magnetic resonance signals into image data for all of the plurality of groups to obtain reconstructed image data for all of the plurality of groups; and
synthesizing the reconstructed image data for all of the plurality of groups.

12. A non-transitory computer-readable storage medium storing a program for controlling a computer to perform the method of claim 6 .

13. The method of claim 6 , wherein the different groups are excited at different times, and
the 3D encoding includes simultaneously encoding in three directions on each of the excited sub-volumes using respectively different encoding methods.

14. The method of claim 6 , wherein the different groups are excited at different times, and
wherein the 3D encoding includes simultaneously encoding of each of the excited sub-volumes for each group in direction that crosses at least two sub-volumes.

15. A magnetic resonance imaging (MRI) system comprising:
an MRI scanner configured to:
apply radio-frequency (RF) pulses comprising a plurality of frequency components and a selection gradient to a subject to simultaneously excite a plurality of sub-volumes in each of a plurality of groups, wherein a plurality of sub-volumes making up a volume of the subject are divided into the plurality of groups so that any neighboring sub-volumes belong to different groups;
perform three-dimensional (3D) encoding on each of the excited sub-volumes using a plurality of encoding methods; and
acquire magnetic resonance signals from the encoded sub-volumes; and

a data processor configured to reconstruct the acquired magnetic resonance signals into image data corresponding to each of the encoded sub-volumes
wherein the plurality of groups comprise a first group through an N-th group, the plurality of sub-volumes making up the volume of the subject are sequentially and cyclically distributed to the first group through the N-th group, and N is an integer greater than or equal to 2.

16. The system of claim 15 , wherein the MRI scanner is further configured to perform the 3D encoding by:
performing a first encoding method in a first direction and a second direction on each of the excited sub-volumes; and
performing a second encoding method in a third direction on each of the excited sub-volumes.

17. The system of claim 16 , wherein the first encoding method comprises radial encoding or spiral encoding; and
the second encoding method comprises Cartesian encoding.

18. The system of claim 15 , wherein the plurality of groups comprise a first group through an N-th group, the plurality of sub-volumes making up the volume of the subject are sequentially and cyclically distributed to the first group through the N-th group, and N is an integer greater than or equal to 2.

19. The system of claim 15 , wherein the MRI scanner comprises gradient coils configured to apply the selection gradient to the subject and perform the 3D encoding on each of the excited sub-volumes by applying to the subject:
a first encoding gradient in a first direction for performing phase encoding with a radial trajectory or a spiral trajectory;
a frequency encoding gradient in a second direction for performing frequency encoding with the radial trajectory or the spiral trajectory; and
a second encoding gradient in a third direction for performing slice encoding with a Cartesian trajectory; and
the third direction is a same direction as a direction in which the selection gradient is applied.

20. The system of claim 15 , wherein the MRI scanner comprises RF coils configured to acquire the magnetic resonance signals from the encoded sub-volumes;
the data processor comprises a reconstructor configured to produce k-spaces from the magnetic resonance

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kim Young Beom
• Ryu Yeunchul
• Yi Jaemock

Classifications

• G01R33/4822

  in three dimensions · CPC title

• G01R33/4826

  in three dimensions · CPC title

• G01R33/4835 Primary

  of multiple slices · 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

• G06T1/00 Primary

  General purpose image data processing · CPC title