Systems and methods of on-the-fly generation of 3D dynamic images using a pre-learned spatial subspace

Patent metadata

Field	Value
Publication number	US-11935158-B2
Application number	US-202117997639-A
Country	US
Kind code	B2
Filing date	May 4, 2021
Priority date	May 4, 2020
Publication date	Mar 19, 2024
Grant date	Mar 19, 2024

Abstract

A method for performing real-time magnetic resonance (MR) imaging on a subject is disclosed. A prep pulse sequence is applied to the subject to obtain a high-quality special subspace, and a direct linear mapping from k-space training data to subspace coordinates. A live pulse sequence is then applied to the subject. During the live pulse sequence, real-time images are constructed using a fast matrix multiplication procedure on a single instance of the k-space training readout (e.g., a single k-space line or trajectory), which can be acquired at a high temporal rate.

First claim

What is claimed is:

1. A method for performing magnetic resonance (MR) imaging on a subject, the method comprising:
applying a first pulse sequence to a region of interest of the subject using an RF transmission system of an MR imaging apparatus;
in response to applying the first pulse sequence to the object, obtaining initial k-space data D 1 using an RF receiving system of the MR imaging apparatus;
constructing a spatial factor U x and a temporal factor Φ from the initial k-space data D 1 using a reconstruction workstation;
determining a transformation T that maps the initial k-space data D 1 to the temporal factor Φ using the reconstruction workstation;
applying a second pulse sequence to the object using the RF transmission system;
obtaining real-time k-space data D 2 at time t using the RF receiving system; and
constructing a real-time image A, where A=U x TD 2 , the real-time image A showing the region of interest of the subject at time t using the reconstruction workstation.

2. A system for performing magnetic resonance (MR) imaging on a subject, comprising:
an MR imaging apparatus that includes:
a magnet operable to provide a magnetic field;
an RF transmission system operable to transmit to a region within the magnetic field; and
an RF receiving system operable to receive a magnetic resonance signal from the region with the magnetic field; and

a reconstruction workstation,
wherein the reconstruction workstation is configured to cause the following method to be performed:
applying a first pulse sequence to a region of interest of the subject using the RF transmission system;
in response to applying the first pulse sequence to the object, obtaining initial k-space data D 1 using the RF receiving system;
constructing a spatial factor U x and a temporal factor Φ from the initial k-space data D 1 using the reconstruction workstation;
determining a transformation T that maps the temporal factor Φ to the initial k-space data D 1 using the reconstruction workstation;
applying a second pulse sequence to the object using the RF transmission system;
obtaining real-time k-space data D 2 at time t using the RF receiving system;
constructing a real-time image A, where A=U x TD 2 , real-time image A showing the region of interest of the subject at time t using the reconstruction workstation.

3. A non-transitory machine-readable medium having stored thereon instructions for performing magnetic resonance (MR) imaging on a subject, which when executed by at least one processor, cause the following method to be performed:
applying a first pulse sequence to a region of interest of the subject using an RF transmission system of an MR imaging apparatus;
in response to applying the first pulse sequence to the object, obtaining initial k-space data D 1 using an RF receiving system of the MR imaging apparatus;
constructing a spatial factor U x and a temporal factor Φ from the initial k-space data D 1 using a reconstruction workstation;
determining a transformation T that maps the initial k-space data D 1 to the temporal factor Φ using the reconstruction workstation;
applying a second pulse sequence to the object using the RF transmission system;
obtaining real-time k-space data D 2 at time t using the RF receiving system; and
constructing a real-time image A, where A=U x TD 2 , real-time image A showing the region of interest of the subject at time t using the reconstruction workstation.

4. A method for performing magnetic resonance (MR) imaging on a subject, the method comprising:
obtaining a set of images of the subject using a reconstruction workstation;
constructing a spatial factor U x and a temporal factor Φ from the set of images of the subject using the reconstruction workstation;
determining a transformation T that maps k-space data to the temporal factor Φ, the k-space data corresponding to the set of images using the reconstruction workstation;
applying a pulse sequence to the object using an RF transmission system of an MR imaging apparatus;
obtaining real-time k-space data D at time t using an RF receiving system of the MR imaging apparatus; and
constructing a real-time image A, where A=U x TD, real-time image A showing the region of interest of the subject at time t using the reconstruction workstation.

5. A system for performing magnetic resonance (MR) imaging on a subject, comprising:
an MR imaging apparatus that includes:
a magnet operable to provide a magnetic field;
an RF transmission system operable to transmit to a region within the magnetic field;
an RF receiving system a receiver operable to receive a magnetic resonance signal from the region with the magnetic field; and

a reconstruction workstation,
wherein the reconstruction workstation is configured to cause the following method to be performed:
obtaining a set of images of the subject using the reconstruction workstation;
constructing a spatial factor U x and a temporal factor Φ from the set of images of the subject using the reconstruction workstation;
determining a transformation T that maps k-space data to the temporal factor Φ, the k-space data corresponding to the set of images using the reconstruction workstation;
applying a pulse sequence to the object using the RF transmission system;
obtaining real-time k-space data D at time t using the RF receiving system; and
constructing a real-time image A, where A=U x TD, real-time image A showing the region of interest of the subject at time t using the reconstruction workstation.

6. A non-transitory machine-readable medium having stored thereon instructions for performing magnetic resonance (MR) imaging on a subject, which when executed by at least one processor, cause the following method to be performed:
obtaining a set of images of the subject using a reconstruction workstation;
constructing a spatial factor U x and a temporal factor Φ from the set of images of the subject using the reconstruction workstation;
determining a transformation T that maps k-space data to the temporal factor Φ, the k-space data corresponding to the set of images using the reconstruction workstation;
applying a pulse sequence to the object using an RF transmission system of an MR imaging apparatus;
obtaining real-time k-space data D at time t using an RF receiving system of an MR imaging apparatus; and
constructing a real-time image A, where A=U x TD, real-time image A showing the region of interest of the subject at time t using the reconstruction workstation.

7. The method of claim 1 , wherein the initial k-space data D 1 includes training data and imaging data.

8. The method of claim 7 , wherein the temporal factor Φ is constructed from the training data.

9. The method of claim 8 , wherein the temporal factor Φ is constructed from only the training data.

10. The method of claim 7 , wherein the spatial factor U x is constructed from the imaging data.

11. The method of claim 10 , wherein the spatial factor U x is constructed from only the imaging data.

12. The method of claim 1 , where the real-time k-space data D 2 includes only real-time training data, such that the image A is constructed from only real-time training data.

13. The method of claim 1 , real-time k-space data D 2 is a single k-space line or trajectory.

14. The method of claim 1 , wherein the image A is calculated using a fast matrix multiplication procedure.

15. The method of claim 1 , wherein T is a linear transformation.

16. The method of claim 1 , wherein the image A is obtained with a temporal resolution of about 50 milliseconds.

Assignees

• Cedars Sinai Medical Center

Inventors

• Christodoulou Anthony
• Fan Zhaoyang
• Li Debiao
• Han Pei

Classifications

• A61B5/055 Primary

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

• G06T12/20

  Inverse problem, i.e. transformations from projection space into object space · CPC title

• G06T12/10 Primary

  Image preprocessing, e.g. calibration, positioning of sources or scatter correction · CPC title

• G06T11/005 Primary

  Physics · mapped topic

• G01R33/4818

  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 title