Biomagnetic resonance device and measuring method therefor

Patent metadata

Field	Value
Publication number	US-9921280-B2
Application number	US-201414446764-A
Country	US
Kind code	B2
Filing date	Jul 30, 2014
Priority date	Jan 31, 2012
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

Provided are an ultra-low-field nuclear magnetic resonance device and an ultra-low-field nuclear magnetic resonance measuring method. The method includes applying a first measurement bias magnetic field corresponding to an excitation frequency of a coherent biomagnetic field generated in association with the electrophysiological activity of human body organs, applying a second measurement bias magnetic field having the same direction as the first measurement bias magnetic field and having a different magnitude than the first measurement bias magnetic field, and measuring a magnetic resonance signal generated in the human body by using magnetic field measuring means.

First claim

What is claimed is:

1. An ultra-low-field nuclear magnetic resonance measuring method comprising:
applying a first measurement bias magnetic field with a Larmor frequency corresponding to an oscillation frequency of a periodical coherent biomagnetic field generated in association with electrophysiological activity of human body organs;
applying a second measurement bias magnetic field, which has a same direction as the first measurement bias magnetic field and a higher magnitude than the first measurement bias magnetic field; and
separating a frequency of a magnetic resonance signal generated in a human body from the oscillation frequency by applying the second measurement bias magnetic field and measuring the magnetic resonance signal using a magnetic field measuring device,
wherein the periodical coherent biomagnetic field is sustained after the second measurement bias magnetic field is applied,
wherein the first measurement bias magnetic field is non-adiabatically changed into the second measurement bias magnetic field, and
wherein the magnetic field measuring device comprises a superconducting quantum interference device (SQUID) or an optically pumped atomic magnetometer.

2. The ultra-low-field nuclear magnetic resonance measuring method of claim 1 , wherein the periodical coherent biomagnetic field has a component on a plane perpendicular to the first measurement bias magnetic field.

3. The ultra-low-field nuclear magnetic resonance measuring method of claim 1 , comprising applying a pre-polarization magnetic field to pre-polarize the human body using a pre-polarizing coil; and
deactivating the pre-polarization magnetic field before measuring the magnetic resonance signal.

4. The ultra-low-field nuclear magnetic resonance measuring method of claim 3 , wherein a direction of the pre-polarization magnetic field matches that of the first measurement bias magnetic field.

5. The ultra-low-field nuclear magnetic resonance measuring method of claim 1 , comprising scanning the magnitude of the first measurement bias magnetic field such that a proton magnetic resonance frequency of the first measurement bias magnetic field matches the oscillation frequency.

6. The ultra-low-field nuclear magnetic resonance measuring method of claim 1 , comprising providing a gradient magnetic field to the human body.

7. The ultra-low-field nuclear magnetic resonance measuring method of claim 6 , wherein the gradient magnetic field includes at least one of a resonance region selection gradient magnetic field, a gradient echo magnetic field, and an encoding gradient magnetic field.

8. The ultra-low-field nuclear magnetic resonance measuring method of claim 7 , wherein the gradient magnetic field comprises the resonance region selection gradient magnetic field, which includes at least one of a first resonance region selection gradient magnetic field, a second resonance region selection gradient magnetic field, and a third resonance region selection gradient magnetic field,
wherein the first resonance region selection gradient magnetic field, the second resonance region selection gradient magnetic field, and the third resonance region selection gradient magnetic field provide gradient magnetic fields with respect to different directions, and
wherein the resonance region selection gradient magnetic field is applied before the second measurement bias magnetic field is applied.

9. The ultra-low-field nuclear magnetic resonance measuring method of claim 7 , wherein the gradient magnetic field comprises the resonance region selection gradient magnetic field and the resonance region selection gradient magnetic field is scanned in a condition such that a sum of the resonance region selection gradient magnetic field and the first measurement bias magnetic field corresponds to the oscillation frequency.

10. The ultra-low-field nuclear magnetic resonance measuring method of claim 7 , wherein the gradient magnetic field comprises the gradient echo magnetic field, which is applied after the second measurement bias magnetic field is applied,
wherein the gradient echo magnetic field includes a first gradient echo magnetic field and a second gradient echo magnetic field that are successively generated, and
wherein the first gradient echo magnetic field and the second gradient echo magnetic field are opposite in direction.

11. The ultra-low-field nuclear magnetic resonance measuring method of claim 7 , wherein the gradient magnetic field comprises the encoding gradient magnetic field, which is applied after the second measurement bias magnetic field is applied,
wherein the encoding gradient magnetic field includes at least one of a first encoding gradient magnetic field and a second encoding gradient magnetic field, and
wherein the encoding gradient magnetic field performs at least one of frequency encoding and phase encoding.

12. A nuclear magnetic resonance measuring method comprising:
selecting a resonant region such that a coherent biomagnetic field, which has an oscillation frequency generated in association with electrophysiological activity of human organs, magnetically resonates with protons processing by a first measurement bias magnetic field; and
spatially imaging a resonant region selected under a second measurement bias magnetic field, which has a same direction as the first measurement bias magnetic field and a different magnitude than the first measurement bias magnetic field, with a magnetic field measuring device,
wherein the coherent biomagnetic field is sustained after the second measurement bias magnetic field is applied,
wherein the first measurement bias magnetic field is non-adiabatically changed into the second measurement bias magnetic field,
wherein the magnetic field measuring device comprises a superconducting quantum interference device (SQUID) or an optically pumped atomic magnetometer, and
wherein the second measurement bias magnetic field has a higher magnitude than the first measurement bias magnetic field.

13. The nuclear magnetic resonance measuring method of claim 12 , wherein selecting the resonant region comprises at least one of:
applying a pre-polarization magnetic field to pre-polarize a human body;
applying the first measurement bias magnetic field, which has a same direction as the pre-polarization magnetic field and is spatially uniform to allow one or more protons to precess;
applying a resonance region selection gradient magnetic field having a same direction as the first measurement bias magnetic field and spatially having a gradient; and
exciting the protons precessed by the first measurement bias magnetic field or the resonance region selection gradient magnetic field magnetically to resonate with the coherent biomagnetic field in a predetermined space or region.

14. The nuclear magnetic resonance measuring method of claim 12 , wherein spatially imaging the resonant region comprises at least one of:
applying the second measurement bias magnetic field, which has a same direction as the first measurement bias magnetic field and a different magnitude than the first measurement bias magnetic field, to the human body;
successively applying a first gradient echo magnetic field and a second gradient echo magnetic field to generate a gradient echo signal;
applying an encoding gradient magnetic field while applying the first gradient echo magnetic field; and
measuring the gradient echo signal while applying the second gradient echo magnetic field.

15. The nuclear magnetic resonance measuring method of claim 14 wherein spatially imaging the resonant region comprises applying the encoding

Assignees

• Korea Res Inst Standards & Sci

Inventors

• Kim Kiwoong
• Lee Yong-Ho
• Lee Seong-Joo
• Yu Kwon-Kyu

Classifications

• G01R33/385 Primary

  using gradient magnetic field coils · CPC title

• A61B5/055 Primary

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

• G01R33/445

  MR involving a non-standard magnetic field B0, e.g. of low magnitude as in the earth's magnetic field or in nanoTesla spectroscopy, comprising a polarizing magnetic field for pre-polarisation, B0 with a temporal variation of its magnitude or direction such as field cycling of B0 or rotation of the direction of B0, or spatially inhomogeneous B0 like in fringe-field MR or in stray-field imaging · CPC title

• G01R33/4806

  Functional imaging of brain activation · CPC title

• G01R33/26

  using optical pumping · CPC title