Magnetic resonance imaging gradient coil, magnet assembly, and system

Patent metadata

Field	Value
Publication number	US-9274192-B2
Application number	US-201113696127-A
Country	US
Kind code	B2
Filing date	May 13, 2011
Priority date	May 20, 2010
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

Abstract

A magnetic resonance imaging magnet assembly ( 100 ) comprising: —a magnet ( 102 ) adapted for generating a main magnetic field for aligning the magnetic spins of nuclei of a subject ( 502 ) located within an imaging volume ( 504 ); and —a gradient coil ( 103 ) for generating a gradient magnetic field for spatial encoding of the magnetic resonance signal of spins of nuclei within the imaging volume, wherein the gradient coil is adapted to be mounted into the magnet, wherein the gradient coil comprises: —a first gradient coil section ( 112 ), wherein the first gradient coil section comprises a first rigid element ( 113 ), —a second gradient coil section ( 114 ), wherein the second gradient coil section also comprises a second rigid element ( 115 ), —a connecting element ( 116, 300, 302, 304, 400 ) for joining the two half gradient coils, wherein the connecting element comprises an elastic material ( 116 ), wherein the elastic material is in contact with the first rigid element and the second rigid element.

First claim

The invention claimed is:

1. A magnetic resonance imaging magnet assembly comprising:
a magnet configured to generate a main magnetic field for aligning the magnetic spins of nuclei of a subject located within an imaging volume; and
a gradient coil configured to generate a gradient magnetic field for spatial encoding of the magnetic resonance signal of spins of nuclei within the imaging volume, wherein the gradient coil is adapted to be mounted into the magnet, wherein the gradient coil comprises:
a first gradient coil section comprising a first rigid element,
a second gradient coil section comprising second rigid element,
a connecting element configured to join the first and second gradient coil sections, the connecting element comprising an elastic material, wherein the elastic material is disposed where the first and second gradient coil sections join, and is in contact with the first rigid element and the second rigid element.

2. The magnetic resonance imaging magnet assembly of claim 1 , wherein each of the first and second gradient coil sections comprise coil windings, wherein the first and second gradient coil sections comprise inner and outer windings, wherein the coil windings comprise flange conductors, wherein the flange conductors are portions of the coil windings that are adapted to conduct current between the inner and out windings, and wherein the flange conductors are adapted to balance the torque exerted on the gradient coil by the main magnetic field during operation of the gradient coil.

3. The magnetic resonance imaging magnet assembly of claim 2 , wherein the coil windings of the first gradient coil section are rigidly attached to the first rigid element, and wherein the coil winding of the second gradient coil section are rigidly attached to the second rigid element.

4. The magnetic resonance imaging magnet assembly of claim 1 , wherein both the first and second rigid elements are elastically mounted to the magnet.

5. The magnetic resonance imaging magnet assembly of claim 1 , the connecting element comprises a viscous element that joins the first and second rigid elements.

6. The magnetic resonance imaging magnet assembly of claim 1 , wherein the connecting element comprises a lap joint.

7. The magnetic resonance imaging magnet assembly of claim 1 , wherein the elastic material of the connecting element is compressed.

8. The magnetic resonance imaging magnet assembly of claim 1 , wherein the first and second gradient coil sections are electrically isolated.

9. The magnetic resonance imaging magnet assembly of claim 8 , wherein the first and second gradient coil sections are connected electrically using bus bars, and wherein the bus bars are mounted elastically to the first and second rigid elements.

10. The magnetic resonance imaging magnet assembly of claim 8 , wherein the first and second gradient coil sections have separate cooling water connections and electrical power connections.

11. The magnetic resonance imaging magnet assembly of claim 1 , wherein the first gradient coil section and the second gradient coil section are torque balanced for Lorentz forces in the magnetic field of the magnet, and wherein the first gradient coil section and the second gradient coil section are translational force balanced for Lorentz forces in the magnetic field of the magnet.

12. The magnetic resonance imaging magnet assembly of claim 1 , wherein the elastic material couples vibrations between the first gradient coil section and the second gradient coil section.

13. The magnetic resonance imaging magnet assembly of claim 1 , wherein the elastic material is a visco-elastic material.

14. A magnetic resonance imaging system comprising:
a magnetic resonance imaging magnet assembly according to any one of the preceding claims;
a radio frequency system configured to acquire magnetic resonance data, wherein the radio frequency system is configured to connect to a radio frequency antenna;
a magnetic field gradient coil power supply configured to supply current to the magnetic field gradient coil; and
a computer system configured to construct images from magnetic resonance data and to control the operation of the magnetic resonance imaging system, wherein the computer system is configured to generate magnetic resonance images of a subject using the magnetic resonance data.

15. A gradient coil configured to generate a magnetic field for spatial encoding of the magnetic spins of nuclei within an imaging volume, wherein gradient coil is adapted to be mounted into a magnet of a magnetic resonance imaging system, the gradient coil comprising:
a first gradient coil section comprising a first rigid element;
a second gradient coil section comprising a second rigid element; and
a connecting element configured to join the first and second gradient coil sections, the connecting element comprising an elastic material, wherein the elastic material is in contact with the first rigid element and the second rigid element.

16. The gradient coil of claim 15 , wherein the first and second gradient coil sections are connected electrically using bus bars, and wherein the bus bars are mounted elastically to the first and second rigid elements.

17. The gradient coil of claim 15 , wherein the first and second gradient coil sections have separate cooling water connections and electrical power connections.

18. The gradient coil of claim 15 , wherein the first gradient coil section and the second gradient coil section are torque balanced for Lorentz forces in the magnetic field of the magnet, and wherein the first gradient coil section and the second gradient coil section are translational force balanced for Lorentz forces in the magnetic field of the magnet.

19. The gradient coil of claim 15 , wherein the elastic material couples vibrations between the first gradient coil section and the second gradient coil section.

20. The gradient coil of claim 15 , wherein each of the first and second gradient coil sections comprises coil windings, wherein the first and second gradient coil sections comprise inner and outer windings, wherein the coil windings comprise flange conductors, wherein the flange conductors are portions of the coil windings that are adapted to conduct current between the inner and out windings, and wherein the flange conductors are adapted to balance the torque exerted on the gradient coil by the main magnetic field during operation of the gradient coil.

Assignees

• Overweg Johannes Adrianus
• Koninkl Philips Nv

Inventors

• Overweg Johannes Adrianus

Classifications

• G01R33/385 Primary

  using gradient magnetic field coils · CPC title

• G01R33/3854 Primary

  means for active and/or passive vibration damping or acoustical noise suppression in gradient magnet coil systems · CPC title

• G01R33/4215

  of the gradient magnetic field, e.g. using passive or active shielding of the gradient magnetic field · CPC title