System and method for magnetic resonance imaging

Patent metadata

Field	Value
Publication number	US-11204408-B2
Application number	US-202016817734-A
Country	US
Kind code	B2
Filing date	Mar 13, 2020
Priority date	Jan 25, 2017
Publication date	Dec 21, 2021
Grant date	Dec 21, 2021

Abstract

The disclosure relates to a system and method for correcting inhomogeneity in an MRI image. The method may include the steps of: acquiring a first set of k-space data, acquiring a second set of k-space data, generating the convolution kernel of the first set of k-space data based on the first set of k-space data and the second set of k-space data, performing inverse Fourier transform on the convolution kernel of the first set of k-space data to obtain an inversely transformed convolution kernel of the first set of k-space data, and generating a corrector based on the inversely transformed convolution kernel of the first set of k-space data. The method may be implemented on a machine including at least one processor and storage.

First claim

We claim:

1. A method for correcting a target image implemented on at least one machine, each of which has at least one processor and at least one storage device, the method comprising:
obtaining the target image, the target image being reconstructed based on a target data set;
obtaining a corrector; and
reducing intensity inhomogeneity of the target image by correcting the target image using the corrector, wherein
the corrector includes a matrix generated based on an inverse Fourier transform of a convolution kernel estimated from a first k-space data set acquired by a first coil and a second k-space data set acquired by a second coil, the second k-space data set having less intensity inhomogeneity than the first k-space data set.

2. The method of claim 1 , wherein the correcting the target image using the corrector comprises:
in response to determining that a size of the corrector is different from a size of the target image, resizing the corrector before correcting the target image using the corrector.

3. The method of claim 2 , wherein the resizing the corrector before correcting the target image using the corrector comprises:
resizing the corrector by tailoring or interpolating the corrector such that the size of the corrector is the same as the size of the target image.

4. The method of claim 1 , wherein the correcting the target image using the corrector comprises:
correcting the target image by multiplying the target image by the corrector.

5. The method of claim 1 , wherein the corrector is generated according to a process including:
obtaining the first k-space data set acquired by the first coil;
obtaining the second k-space data set acquired by the second coil;
generating the convolution kernel based on the first k-space data set and the second k-space data set;
generating an inversely transformed convolution kernel by performing an inverse Fourier transform on the convolution kernel; and
generating the corrector based on the inversely transformed convolution kernel.

6. The method of claim 5 , wherein the performing an inverse Fourier transform on the convolution kernel includes:
generating a complex conjugate of the convolution kernel;
providing an initial data set filled with zeroes;
populating the initial data set with the complex conjugate of the convolutional kernel; and
performing the inverse Fourier transform on the populated data set.

7. The method of claim 6 , wherein a size of the initial data set is associated with a size of the first k-space data set or the second k-space data set.

8. The method of claim 5 , wherein the generating the corrector based on the inversely transformed convolution kernel comprises:
in response to determining that a size of the inversely transformed convolution kernel is different from a size of the target image,
resizing the inversely transformed convolution kernel such that the size of the inversely transformed convolution kernel is the same as the size of the target image; and
designating the resized inversely transformed convolution kernel as the corrector.

9. The method of claim 5 , wherein the generating the corrector based on the inversely transformed convolution kernel comprises:
designating the inversely transformed convolution kernel as the corrector.

10. The method of claim 5 , wherein the obtaining the first k-space data set acquired by the first coil comprises:
acquiring a first image data set associated with the first coil; and
obtaining the first k-space data set by performing a Fourier transform on the first image data set.

11. The method of claim 5 , wherein the obtaining the second k-space data set acquired by the second coil comprises:
acquiring a second image data set associated with the second coil; and
obtaining the second k-space data set by performing a Fourier transform on the second image data set.

12. The method of claim 1 , wherein the first coil includes a surface coil.

13. The method of claim 1 , wherein the second coil includes a body coil.

14. The method of claim 1 , wherein the target data set is acquired by the first coil.

15. The method of claim 1 , wherein the target data set, the first k-space data set, and the second k-space data set are associated with a same subject or a same region of the subject.

16. The method of claim 1 , wherein the first k-space data set and the second k-space data set are associated with a same subject, and the target data set is associated with a region of the subject.

17. The method of claim 1 , wherein the first k-space data set and the second k-space data set are acquired during a pre-scan.

18. The method of claim 1 , wherein the first k-space data set and the second k-space data set are of a same size.

19. A system for correcting a target image, comprising:
at least one storage device storing a set of instructions; and
at least one processor in communication with the storage device, wherein when executing the set of instructions, the at least one processor is configured to cause the system to perform operations including:
obtaining the target image, the target image being reconstructed based on a target data set;
obtaining a corrector; and
reducing intensity inhomogeneity of the target image by correcting the target image using the corrector, wherein
the corrector includes a matrix generated based on an inverse Fourier transform of a convolution kernel estimated from a first k-space data set acquired by a first coil and a second k-space data set acquired by a second coil,
the second k-space data set having less intensity inhomogeneity than the first k-space data set.

20. A non-transitory computer readable medium, comprising at least one set of instructions for correcting a target image, wherein when executed by one or more processors of a computing device, the at least one set of instructions causes the computing device to perform a method, the method comprising:
obtaining the target image, the target image being reconstructed based on a target data set;
obtaining a corrector; and
reducing intensity inhomogeneity of the target image by correcting the target image using the corrector, wherein
the corrector includes a matrix generated based on an inverse Fourier transform of a convolution kernel estimated from a first k-space data set acquired by a first coil and a second k-space data set acquired by a second coil, the second k-space data set having less intensity inhomogeneity than the first k-space data set.

Assignees

• Shanghai United Imaging Healthcare Co Ltd

Inventors

• Ding Yu
• He Renjie

Classifications

• A61B5/055

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

• G01R33/5659 Primary

  caused by a distortion of the RF magnetic field, e.g. spatial inhomogeneities of the RF magnetic field (G01R33/56509, G01R33/56518, G01R33/56536 take precedence) · CPC title

• A61B5/0013

  Medical image data (A61B1/00011, A61B6/56, A61B8/56 take precedence) · CPC title

• A61B5/7257

  using Fourier transforms · CPC title

• A61B2576/00

  Medical imaging apparatus involving image processing or analysis (A61B1/00009, A61B6/52 and A61B8/52 take precedence) · CPC title