Magnetic resonance imaging apparatus and method of generating magnetic resonance image by using the same

• US 10,473,742 B2
• Filed: 02/14/2017
• Issued: 11/12/2019
• Est. Priority Date: 03/02/2016
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choi, Joon-sung, Hwang, Jin-young
• Primary Examiner(s): Patel, Rishi R
• Application Number:
  US15/432,376
• Publication Number:
  US 20170254867A1
• Time in Patent Office: 1,001 Days
• CPC Class Codes: G01R 33/4818 MR characterised by data acquisition along a specific k-space trajectory or by the temporal order of k-space coverage, e.g. centric or segmented coverage of k-space
• CPC Class Codes: G01R 33/482 using a Cartesian trajectory
• CPC Class Codes: G01R 33/4824 using a non-Cartesian trajectory
• CPC Class Codes: G01R 33/4833 using spatially selective excitation of the volume of interest, e.g. selecting non-orthogonal or inclined slices
• 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 33/5613 Generating steady state signals, e.g. low flip angle sequences [FLASH]
• CPC Class Codes: G01R 33/5616 using gradient refocusing, e.g. EPI
• CPC Class Codes: G01R 33/56509 due to motion, displacement or flow, e.g. gradient moment nulling G01R33/567 takes precedence

Abstract

A magnetic resonance imaging apparatus includes a radio frequency (RF) controller configured to, during a repetition time (TR) period among TR periods, apply at least one RF pulse corresponding to a first slice to an object, and apply a navigator RF pulse corresponding to a second slice adjacent to the first slice to the object, a data obtainer configured to, during the TR period, obtain first k-space data corresponding to the applied at least one RF pulse, and obtain second k-space data corresponding to the applied navigator RF pulse, and an image processor configured to generate navigator images, based on pieces of second k-space data that are obtained during the TR periods, the pieces comprising the second k-space obtained during the TR period, correct the first k-space data, based on the navigator images, and generate a magnetic resonance image of the first slice, based on the corrected first k-space data.

Claims

1. A magnetic resonance imaging (MRI) apparatus for generating a magnetic resonance (MR) image during repetition time (TR) periods, the MRI apparatus comprising:

a radio frequency (RF) controller configured to, during each TR period of the TR periods;

apply a plurality of RF pulses corresponding to a first single slice to an object; and

apply a single navigator RF pulse corresponding to a second single slice adjacent to the first single slice to the object after the plurality of RF pulses are applied;

a signal transceiver configured to, during each TR period of the TR periods;

obtain first k-space data corresponding to the applied plurality of RF pulses; and

obtain second k-space data corresponding to the applied single navigator RF pulse; and

an image processor configured to;

generate navigator images, based on pieces of the second k-space data that are obtained during the TR periods, the pieces comprising the second k-space data obtained during each TR period of the TR periods;

correct the first k-space data, based on the navigator images; and

generate the MR image of the first single slice, based on the corrected first k-space data.

2. The MRI apparatus of claim 1, wherein the signal transceiver is further configured to:

arrange the first k-space data in a part of a first k-space; and

arrange the second k-space data in an entirety of a second k-space.

3. The MRI apparatus of claim 1, wherein each of the navigator images is generated based on an entirety of a second k-space in which the second k-space data is arranged.

4. The MRI apparatus of claim 1, wherein a first echo time (TE) corresponding to the plurality of RF pulses is longer than a second TE corresponding to the single navigator RF pulse.

5. The MRI apparatus of claim 1, wherein the image processor is further configured to:

select a reference navigator image from the navigator images; and

correct the first k-space data, based on a difference between the navigator images and the selected reference navigator image.

6. The MRI apparatus of claim 5, wherein the image processor is further configured to:

divide the reference navigator image into reference blocks;

divide the navigator images into comparison blocks respectively corresponding to the reference blocks; and

correct the first k-space data, based on a difference between vector information of the reference blocks and vector information of the comparison blocks.

7. The MRI apparatus of claim 1, wherein the RF controller is further configured to apply the single navigator RF pulse to the object at regular TR period intervals during the TR periods.

8. The MRI apparatus of claim 1, wherein the navigator images have a resolution lower than a resolution of the MR image.

9. The MRI apparatus of claim 1, wherein the RF controller is further configured to apply RF pulses corresponding to the first single slice to the object, based on a fast spin-echo technique.

10. The MRI apparatus of claim 1, wherein the RF controller is further configured to apply the single navigator RF pulse to the object, based on an echo-planar imaging technique.

20. The MRI apparatus of claim 1, wherein the plurality of RF pulses comprises a single 90-degree RF pulse and a plurality of 180-degree RF pulses after the single 90-degree RF pulse.

11. A method of generating a magnetic resonance (MR) image during repetition time (TR) periods, the method being performed by a magnetic resonance imaging (MRI) apparatus, and the method comprising:

applying a plurality of radio frequency (RF) pulses corresponding to a first single slice to an object, and applying a single navigator RF pulse corresponding to a second single slice adjacent to the first single slice to the object after the plurality of RF pulses are applied, during each TR period of the TR periods;

obtaining first k-space data corresponding to the applied plurality of RF pulses, and obtaining second k-space data corresponding to the applied single navigator RF pulse, during each TR period of the TR periods;

generating navigator images, based on pieces of the second k-space data that are obtained during the TR periods, the pieces comprising the second k-space data obtained during each TR period of the TR periods;

correcting the first k-space data, based on the navigator images; and

generating the MR image of the first single slice, based on the corrected first k-space data.

12. The method of claim 11, wherein the obtaining of the first k-space data comprises arranging the first k-space data in a part of a first k-space, and

the obtaining of the second k-space data comprises arranging the second k-space data in an entirety of a second k-space.

13. The method of claim 11, wherein the correcting of the first k-space data comprises:

selecting a reference navigator image from the navigator images; and

correcting the first k-space data, based on a difference between the navigator images and the selected reference navigator image.

14. The method of claim 13, wherein the correcting of the first k-space data comprises:

dividing the reference navigator image into reference blocks;

dividing the navigator images into comparison blocks respectively corresponding to the reference blocks; and

correcting the first k-space data, based on a difference between vector information of the reference blocks and vector information of the comparison blocks.

15. The method of claim 11, wherein the applying of the single navigator RF pulse comprises applying the single navigator RF pulse to the object at regular TR period intervals during the TR periods.

16. The method of claim 11, wherein the navigator images have a resolution lower than a resolution of the MR image.

17. The method of claim 11, wherein the applying of the plurality of RF pulses comprises applying RF pulses corresponding to the first single slice to the object, based on a fast spin-echo technique.

18. The method of claim 11, wherein the applying of the single navigator RF pulse comprises applying the single navigator RF pulse to the object, based on an echo-planar imaging technique.

19. A non-transitory computer-readable storage medium storing a program for causing a computer to perform the method of claim 11.