Integrated sheath current filter in a local coil

Patent metadata

Field	Value
Publication number	US-9244141-B2
Application number	US-201213553623-A
Country	US
Kind code	B2
Filing date	Jul 19, 2012
Priority date	Jul 21, 2011
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

Abstract

A local coil for an imaging system includes a sheath current filter and one or more lines run through the sheath current filter.

First claim

The invention claimed is:

1. A local coil for an imaging system, the local coil comprising:
a sheath current filter; and
one or more signal lines that run through the sheath current filter,
wherein at least one of the signal lines runs from outside of the local coil into an interior of the local coil through the sheath current filter.

2. The local coil as claimed in claim 1 , wherein the sheath current filter is within the imaging system, the imaging system comprising a magnetic resonance tomography (MRT) system.

3. The local coil as claimed in claim 1 , wherein the one or more signal lines are insulated from the sheath current filter in an electrically non-conductive manner, are inductively coupled to the sheath current filter, or a combination thereof.

4. The local coil as claimed in claim 3 , wherein the one or more signal lines are electrically insulated from oscillating circuits of the sheath current filter and are inductively coupled to the oscillating circuits.

5. The local coil as claimed in claim 1 , wherein the sheath current filter is located on or completely or partially in a housing of the local coil between an inner surface of the housing facing a patient and an outer surface of the housing facing the imaging system.

6. The local coil as claimed in claim 1 , wherein the one or more lines are one or more signaling lines.

7. The local coil as claimed in claim 1 , wherein a circumferentially continuous, uninterrupted, or circumferentially continuous and uninterrupted conductive layer, through which the signal lines are run is provided on an opening of the sheath current filter.

8. The local coil as claimed in claim 7 , wherein the circumferentially continuous, uninterrupted, or circumferentially continuous and uninterrupted conductive layer is a copper layer.

9. The local coil as claimed in claim 1 , wherein the one or more signal lines are connected to a loudspeaker/headphone, a display, electrodes, receive coils, or a combination thereof inside the local coil.

10. The local coil as claimed in claim 1 , wherein the local coil is a magnetic resonance tomography (MRT) head coil.

11. The local coil as claimed in claim 1 , wherein the sheath current filter is arranged on a head end of the local coil.

12. The local coil as claimed in claim 1 , wherein a housing of the sheath current filter is uninterrupted, enclosed, or uninterrupted and enclosed along a circumference.

13. The local coil as claimed in claim 12 , wherein the circumference is a circumference around a z direction.

14. The local coil as claimed in claim 1 , wherein the sheath current filter comprises at least two parts that are operable to be taken apart and reassembled again.

15. The local coil as claimed in claim 14 , wherein a housing of the sheath current filter comprises the at least two parts.

16. The local coil as claimed in claim 1 , wherein the one or more signal lines are shielded, twisted, a parallel wire line, or a combination thereof.

17. The local coil as claimed in claim 1 , wherein the sheath current filter comprises a shortened quarter-wave balun.

18. The local coil as claimed in claim 1 , wherein the sheath current filter comprises a coated plastic carrier with a conductive layer.

19. The local coil as claimed in claim 18 , wherein the conductive layer is a copper layer.

20. The local coil as claimed in claim 1 , wherein the sheath current filter comprises a plastic carrier coated with a conductive layer.

21. The local coil as claimed in claim 20 , wherein the conductive layer is a copper layer on an inside, an outside, or the inside and the outside of the plastic carrier.

22. The local coil as claimed in claim 1 , wherein a conductive layer on the outside of the sheath current filter comprises an interruption.

23. The local coil as claimed in claim 22 , wherein the interruption is in a longitudinal direction approximately in the center.

24. The local coil as claimed in claim 1 , wherein a copper layer on the outside of the sheath current filter comprises an interruption bridged by one or more capacitors.

25. The local coil as claimed in claim 1 , wherein capacitors of the sheath current filter form an electrical resonant circuit, wherein a resonant frequency of the capacitors is a working frequency of the imaging system, or a combination thereof.

26. The local coil as claimed in claim 1 , wherein a resonant frequency of the sheath current filter is not influenced by the number of the one or more signal lines guided through the sheath current filter.

27. The local coil as claimed in claim 1 , wherein the sheath current filter is separable into at least two parts.

28. The local coil as claimed in claim 27 , wherein the at least two parts are combined parts with uninterrupted shielding of the sheath current filter.

29. The local coil as claimed in claim 27 , wherein when the at least two parts abut each other, a conductive layer of one part of the at least two parts and a conductive layer of another part of the at least two parts are connected to each other in an electrically conductive manner.

30. The local coil as claimed in claim 1 , wherein the sheath current filter is separable into at least two parts with shielding that overlaps in a combined condition of the at least two parts.

31. The local coil as claimed in claim 1 , wherein the sheath current filter is separable into two half shells that abut each other.

32. The local coil as claimed in claim 31 , wherein the sheath current filter is separable into the two half shells that abut each other with an air gap between the two half shells.

33. The local coil as claimed in claim 1 , wherein the sheath current filter is enclosed.

34. The local coil as claimed in claim 33 , wherein the sheath current filter is enclosed with an upper part and a lower part that are firmly connected to each other.

35. The local coil as claimed in claim 1 , wherein an attachment device for the one or more signal lines is provided at one end or both ends of the one or more signal lines.

36. The local coil as claimed in claim 35 , wherein the attachment device comprises a socket or a plug.

37. The local coil as claimed in claim 1 , wherein the one or more signal lines run on one side to a connector on a patient bed, and run into the local coil on the other side with or without interruption through a plug-in connection.

Assignees

• Greim Helmut
• Siemens Ag

Inventors

• Greim Helmut

Classifications

• G01R33/3415

  comprising arrays of sub-coils {, i.e. phased-array coils with flexible receiver channels} · CPC title

• G01R33/34046

  Volume type coils, e.g. bird-cage coils; Quadrature bird-cage coils; Circularly polarised coils · CPC title

• G01R33/283

  Intercom or optical viewing arrangements, structurally associated with NMR apparatus · CPC title

• G01R33/3685 Primary

  Means for reducing sheath currents, e.g. RF traps, baluns · CPC title

• G01R33/422 Primary

  of the radio frequency field · CPC title