Method for electromagnetic shielding for a magnetic resonance system and correspondingly shielded device

Patent metadata

Field	Value
Publication number	US-9817095-B2
Application number	US-201313928539-A
Country	US
Kind code	B2
Filing date	Jun 27, 2013
Priority date	Jul 18, 2012
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

In one embodiment, an electromagnetic shielding of a device is disclosed for a magnetic resonance system. The device is shielded via a conductive layer which surrounds an inner part of the device in such a manner that an electrical current path completely around the inner part can be formed in the layer. The layer is arranged between a housing of the device, surrounding the inner part, and the inner part. In another embodiment, an electromagnetic shielding of a device is disclosed for a magnetic resonance system, wherein the device is shielded via a conductive layer which surrounds the device in such a manner that an electrical current path completely around the device is formed. In this situation, the device having the layer is mounted by way of projections on the magnetic resonance system. Each projection has a contact surface with the layer, at which the respective projection contacts the layer.

First claim

The invention claimed is:

1. A method for electromagnetic shielding of a device for a magnetic resonance system, comprising:
shielding the device using a conductive layer, which is attached to a carrier tube recess only by tangential contact with a surface of at least one semi-circular projection and which surrounds an inner part of the device in such a manner that an electrical current path completely around the inner part is formable in the conductive layer, the conductive layer being arranged between a housing of the device, which surrounds the inner part, and the inner part.

2. The method of claim 1 , wherein an electrical insulation is arranged between the conductive layer and the inner part.

3. The method of claim 2 , wherein a thickness of the conductive layer is chosen dependent on a magnetic field of the magnetic resonance system in such a manner that an influence of the magnetic field in respect of a switching of magnetic field gradients of the magnetic resonance system is heavily attenuated, but the magnetic field gradients are almost not attenuated by electrical currents which are induced in the layer.

4. The method of claim 2 , wherein the conductive layer has a thickness of less than 50 μm.

5. The method of claim 2 , the conductive layer is formed from copper.

6. The method of claim 1 , wherein a thickness of the conductive layer is chosen dependent on a magnetic field of the magnetic resonance system in such a manner that an influence of the magnetic field in respect of a switching of magnetic field gradients of the magnetic resonance system is heavily attenuated, but the magnetic field gradients are almost not attenuated by electrical currents which are induced in the layer.

7. The method of claim 1 , wherein the conductive layer has a thickness of less than 50 μm.

8. The method of claim 1 , the conductive layer is formed from copper.

9. A method for electromagnetic shielding of a device for a magnetic resonance system, comprising:
shielding the device using a conductive layer which surrounds the device in such a manner that an electrical current path completely around the device is formable, the device with the conductive layer being mounted on a carrier tube recess of the magnetic resonance system only by tangential contact with semi-circular projections, and each of the projections including a tangential contact surface with the conductive layer, at which each respective projection contacts the conductive layer.

10. The method of claim 9 , wherein the maximum length dimension of the contact surface is shorter than 3 cm.

11. The method of claim 9 , wherein the contact surface is circular in shape.

12. The method of claim 9 , further comprising:
shielding the device using another conductive layer which surrounds an inner part of the device in such a manner that an electrical current path completely around the inner part is formable in the another conductive layer, the another conductive layer being arranged between a housing of the device, which surrounds the inner part, and the inner part.

13. The method of claim 12 , wherein a sum of a thicknesses of the conductive layer and the another conductive layer, in comparison with an operational situation in which the device were to be shielded only with one of the two conductive layers, essentially corresponds to the thickness of the one conductive layer.

14. A device for a magnetic resonance system, comprising:
an inner part;
a housing surrounding the inner part; and
a conductive layer, for electromagnetic shielding from the magnetic resonance system, surrounding the inner part in such a manner that an electrical current path completely around the inner part is formable in the conductive layer, the conductive layer being attached to a carrier tube recess only by tangential contact with a surface of a semi-circular projection and being arranged between the inner part and the housing.

15. The device of claim 14 , further comprising a PET detector.

16. The device of claim 14 , further comprising:
a magnetic resonance system around the device.

17. A device for a magnetic resonance system, comprising:
a conductive layer; and
semi-circular projections surrounding a remainder of the device to mount the conductive layer of the device on a carrier tube recess of the magnetic resonance system, wherein for electromagnetic shielding from the magnetic resonance system, the conductive layer surrounds the remainder of the device in such a manner that an electrical current path completely around the device is formable in the conductive layer, the device being mounted on the magnetic resonance system only via tangential contact with a surface of the projections, each of the projections including a contact surface with the conductive layer at which each of the respective projections contacts the conductive layer.

18. The device of claim 17 , further comprising a PET detector.

19. The device of claim 17 , further comprising
a magnetic resonance system around the device.

Assignees

• Siemens Ag
• Siemens Medical Solutions Usa Inc

Inventors

• Corbeil James
• Ladebeck Ralf
• Stocker Stefan

Classifications

• G01R33/481

  MR combined with positron emission tomography [PET] or single photon emission computed tomography [SPECT] · CPC title

• G01R33/42 Primary

  Screening · CPC title

• G01R33/4215 Primary

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