APPARATUS AND METHOD FOR DECOUPLING MR COILS

• US 20110148415A1
• Filed: 12/21/2009
• Published: 06/23/2011
• Est. Priority Date: 12/21/2009
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Boskamp, Eddy Benjamin
• Granted Patent: US 8,258,789 B2
• Time in Patent Office: Days
• US Class Current: 324/318
• CPC Class Codes: G01R 33/34007 Manufacture of RF coils, e.g. using printed circuit board technology; additional hardware for providing mechanical support to the RF coil assembly or to part thereof, e.g. a support for moving the coil assembly relative to the remainder of the MR system
• CPC Class Codes: G01R 33/3415 comprising arrays of sub-coils , i.e. phased-array coils with flexible receiver channels
• CPC Class Codes: G01R 33/365 Decoupling of multiple RF coils wherein the multiple RF coils have the same function in MR, e.g. decoupling of a receive coil from another receive coil in a receive coil array, decoupling of a transmission coil from another transmission coil in a transmission coil array

Abstract

An apparatus includes a first RF coil integrated into a first printed circuit board (PCB) and a second RF coil integrated into the first PCB. The apparatus also includes a tuning member positioned adjacently to the first PCB and inductively coupled to the first and second RF coils, the tuning member configured to minimize a mutual inductance formed between the first and second RF coils via modification of a coupling constant between the first and second RF coils.

Claims

1. An apparatus comprising:

a first RF coil integrated into a first printed circuit board (PCB);

a second RF coil integrated into the first PCB;

a tuning member positioned adjacently to the first PCB and inductively coupled to the first and second RF coils, the tuning member configured to minimize a mutual inductance formed between the first and second RF coils via modification of a coupling constant between the first and second RF coils.

2. The apparatus of claim 1 wherein the tuning member comprises an electrically conductive material integrated into a second PCB.

3. The apparatus of claim 2 wherein the electrically conductive material is formed into a loop.

4. The apparatus of claim 3 wherein the loop comprises a plurality of turns.

5. The apparatus of claim 3 further comprising a capacitor coupled in series with the loop.

6. The apparatus of claim 1 wherein the tuning member comprises a layer of copper foil.

7. The apparatus of claim 1 wherein the tuning member is configured to reduce a coupling of the first and second RF coils.

8. The apparatus of claim 1 wherein the tuning member is configured to increase a coupling of the first and second RF coils.

9. The apparatus of claim 1 further comprising a transformer integrated into the PCB between the first and second RF coils, the transformer comprising:

a first winding coupled in series with the first RF coil; and

a second winding coupled in series with the second RF coil.

10. The apparatus of claim 9 wherein the tuning member is positioned adjacently to the transformer.

11. The apparatus of claim 10 wherein the tuning member overlaps a portion of the transformer.

12. A method comprising:

forming a first RF coil in a first printed circuit board (PCB);

forming a second RF coil in the first PCB;

forming an inductive member; and

positioning the inductive member adjacently to the first PCB such that the inductive member is inductively coupled to the first and second RF coils and such that the inductive member minimizes a mutual inductance between the first and second RF coils.

13. The method of claim 12 further comprising measuring an inductive coupling of the first and second RF coils;

and

wherein positioning the inductive member comprises;

positioning the inductive member adjacently to a region between the first and second RF coils; and

tuning the inductive coupling of the first and second RF coils via a position of the inductive member such that the inductive coupling is substantially eliminated.

14. The method of claim 13 wherein tuning comprises:

rotating the inductive member; and

fixing the inductive member to the first PCB at a position configured to substantially eliminate the inductive coupling.

15. The method of claim 13 further comprising:

forming a first transformer winding in the first PCB and in the region between the first and second RF coils, the first transformer winding serially coupled to the first RF coil;

forming a second transformer winding in the first PCB and in the region between the first and second RF coils, the second transformer winding serially coupled to the second RF coil and overlapping the first transformer winding, wherein the first and second transformer windings form a transformer;

wherein positioning the inductive member adjacently to the region between the first and second RF coils comprises positioning the inductive member adjacently to the transformer; and

wherein tuning the inductive coupling of the first and second RF coils comprises varying an amount of overlap between the inductive member and the transformer such that the inductive coupling is substantially eliminated.

16. The method of claim 12 wherein forming the inductive member comprises forming the inductive member on a second PCB.

17. An apparatus comprising:

a first plurality of RF coils formed onto a printed circuit board (PCB), each coil of the first plurality of RF coils overlapping another coil of the first plurality of RF coils;

a second plurality of RF coils formed onto the PCB, each coil of the second plurality of RF coils overlapping another coil of the second plurality of RF coils, wherein the second plurality of RF coils is adjacent to the first plurality of RF coils; and

a first plurality of tuning members, each tuning member configured to reduce a coupling of a first respective pair of coils via an inductive coupling with each coil of the first respective pair of coils, wherein each first respective pair of coils comprises;

a coil of the first plurality of RF coils; and

a neighboring coil of the second plurality of RF coils.

18. The apparatus of claim 17 further comprising:

a plurality of transformers coupled to the first and second plurality of RF coils, each of the first respective pair of coils coupled to a respective transformer of the plurality of transformers, wherein each transformer comprises;

a first winding serially coupled with one of the first respective pairs of coils; and

a second winding serially coupled with the other of the first respective pairs of coils, wherein the first and second windings overlap each other.

19. The apparatus of claim 18 wherein each tuning member of the first plurality of tuning members is positioned adjacently to a respective transformer of the plurality of transformers.

20. The apparatus of claim 17 further comprising a second plurality of tuning members, each tuning member of the second plurality of tuning members configured to reduce a coupling of a second respective pair of coils via an inductive coupling with each coil of the second respective pair of coils, wherein each second respective pair of coils comprises:

a first coil of one of the first and second plurality of RF coils; and

a second coil of the one of the first and second plurality of RF coils, were the first and second coils overlap.