TRANSFORMER ASSEMBLY FOR A MAGNETIC RESONANCE IMAGING SYSTEM

• US 20120001715A1
• Filed: 08/09/2011
• Published: 01/05/2012
• Est. Priority Date: 06/10/2010
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: TARACILA, VICTOR, ROBB, FRASER, ZEMSKOV, ALEKSEY, ALAGAPPAN, VIJAYANAND, NAVARRO, MIGUEL
• Granted Patent: US 8,928,450 B2
• Time in Patent Office: Days
• US Class Current: 336/200
• 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
• CPC Class Codes: H01F 19/04 Transformers or mutual inductances suitable for handling frequencies considerably beyond the audio range resonant circuits H03H
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

A transformer assembly includes a substrate having a first surface and an opposing second surface, a first spiral wound inductive coil formed on the first surface, a second spiral wound inductive coil formed on the first surface, and a third spiral wound inductive coil formed on the first surface, the first, second and third spiral wound inductive coils forming a triple spiral arrangement on the first surface such that the first coil is inductively coupled to the second coil and the third coil. An RF coil including the transformer assembly and a method of fabricating the transformer assembly are also described.

Claims

1. A transformer assembly comprising:

a substrate having a first surface and an opposing second surface;

a first spiral wound inductive coil formed on the first surface;

a second spiral wound inductive coil formed on the first surface; and

a third spiral wound inductive coil formed on the first surface, the first, second and third spiral wound inductive coils forming a triple spiral arrangement on the first surface such that the first coil is inductively coupled to the second coil and the third coil.

2. A transformer assembly in accordance with claim 1, wherein the transformer assembly has a mutual inductance that is substantially zero.

3. A transformer assembly in accordance with claim 1, wherein the first, second and third coils have a substantially hexagonal cross-sectional profile.

4. A transformer assembly in accordance with claim 1, wherein the first, second and third coils have a substantially rectangular cross-sectional profile.

5. A transformer assembly in accordance with claim 1, wherein the first, second and third spiral wound inductive coils comprise:

a first spiral wound inductive coil portion formed on the first surface; and

a second spiral wound inductive coil portion formed on the second surface, the first spiral wound inductive coil portions being symmetrical with the second spiral wound inductive coil portion.

6. A transformer assembly in accordance with claim 1, wherein the first coil includes a plurality of turns that are interleaved with the second coil and the third coil.

7. A transformer assembly in accordance with claim 1, wherein the substrate is fabricated from a dielectric material and the first, second and third coils are fabricated from a copper material.

8. A transformer assembly in accordance with claim 1, wherein the first and second coils include a plurality of turns that are coplanar.

9. A multiple channel array coil for magnetic resonance imaging, comprising:

a first coil;

a second coil;

a third coil; and

a transformer coupled between the first, second, and third coils, the transformer comprising;

a substrate having a first surface and an opposing second surface;

a first spiral wound inductive coil formed on the first surface;

a second spiral wound inductive coil formed on the first surface; and

a third spiral wound inductive coil formed on the first surface;

the first, second and third spiral wound inductive coils forming a triple spiral arrangement on the first surface such that the first coil is inductively coupled to the second and third coils.

10. An array coil in accordance with claim 9, wherein the transformer has a mutual inductance that is substantially zero.

11. An array coil in accordance with claim 9, wherein the first, second and third coils have a substantially hexagonal cross-sectional profile.

12. An array coil in accordance with claim 9, wherein the first, second and third coils have a substantially rectangular cross-sectional profile.

13. An array coil in accordance with claim 9, wherein the first, second and third spiral wound inductive coils comprise:

a first spiral wound inductive coil portion formed on the first surface; and

a second spiral wound inductive coil portion formed on the second surface, the first spiral wound inductive coil portions being symmetrical with the second spiral wound inductive coil portion.

14. An array coil in accordance with claim 9, wherein the first coil includes a plurality of turns that are interleaved with the second coil and the third coil.

15. An array coil in accordance with claim 9, wherein the substrate is fabricated from a dielectric material and the first, second and third coils are fabricated from a copper material.

16. An array coil in accordance with claim 9, wherein the first and second coils include a plurality of turns that are coplanar.

17. A method of fabricating a transformer assembly, said method comprising:

forming a first spiral electrical inductor on a first surface of a dielectric substrate;

forming a second spiral electrical inductor on the first surface of the substrate; and

forming a third spiral electrical inductor on a first surface of a dielectric substrate;

such that the first spiral inductor is interleaved with the second and third spiral inductors.

18. The method of claim 17, wherein forming the first, second and third spiral electrical inductors comprises:

providing a first spiral inductor portion on the first surface of a dielectric substrate;

providing a second spiral inductor portion on an opposing second surface of the dielectric substrate; and

connecting the first spiral inductor portion and the second spiral inductor portion to a single contact.

19. The method of claim 17, wherein the transformer assembly has a mutual inductance that is substantially zero.

20. The method of claim 17, wherein the first, second and third coils have a substantially hexagonal cross-sectional profile.