TRANSFORMER ASSEMBLY FOR A MAGNETIC RESONANCE IMAGING SYSTEM

• US 20110304422A1
• Filed: 06/10/2010
• Published: 12/15/2011
• 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 8,674,799 B2
• Time in Patent Office: Days
• US Class Current: 336/200
• 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 33/3628 Tuning/matching of the transmit/receive coil
• 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 21/12 discontinuously variable, e.g. tapped
• 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, and a second spiral wound inductive coil formed on the first surface; the first and second spiral wound inductive coils forming a double spiral arrangement on the first surface such that the first coil is inductively coupled to the second 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; and

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

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

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

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

a second spiral wound inductive coil portion formed on the second surface,

a plurality of openings extending through the first and second surfaces; and

a metallic pin configured to be inserted in at least one of the openings, the pin coupling the first spiral wound inductive coil portion to the second spiral wound inductive coil portion.

3. A transformer assembly in accordance with claim 1 wherein the first and second 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 portions.

4. A transformer assembly in accordance with claim 1 wherein the first and second coils are configured to be electrically coupled to a respective capacitor, the first and second coils comprising a plurality of openings extending through the first and second surfaces, and a metallic pin configured to be inserted into one of the plurality of openings, the pins being inserted into the openings to adjust the mutual inductance of the transformer assembly.

5. A transformer assembly in accordance with claim 1 wherein the first and second coils are configured to be electrically coupled in series to a respective capacitor, the first and second coils comprising a plurality of openings extending through the first and second surfaces, and a metallic pin configured to be inserted into one of the plurality of openings, the pins being inserted into the openings based on the capacitance of the capacitors.

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.

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

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

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

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

a first coil;

a second coil; and

a transformer coupled between the first and second 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; and

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

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

11. An array coil in accordance with claim 10 wherein the first and second spiral wound inductive coils comprise:

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

a second spiral wound inductive coil portion formed on the second surface,

a plurality of openings extending through the first and second surfaces; and

a metallic pin configured to be inserted in at least one of the openings, the pin coupling the first spiral wound inductive coil portion to the second spiral wound inductive coil portion.

12. An array coil in accordance with claim 10 wherein the first and second spiral wound inductive coils are configured to be electrically coupled to a respective capacitor, the first and second coils comprising a plurality of openings extending through the first and second surfaces, and a metallic pin configured to be inserted into one of the plurality of openings, the pins being inserted into the openings to adjust the mutual inductance of the transformer assembly.

13. An array coil in accordance with claim 10 wherein the first and second coils are configured to be electrically coupled in series to a respective capacitor, the first and second coils comprising a plurality of openings extending through the first and second surfaces, and a metallic pin configured to be inserted into one of the plurality of openings, the pins being inserted into the openings based on the capacitance of the capacitors.

14. An array coil in accordance with claim 10 wherein the first coil includes a plurality of turns that are interleaved with the second coil.

15. An array coil in accordance with claim 10 wherein the first and second spiral have a substantially rectangular cross-sectional profile.

16. An array coil in accordance with claim 10 the substrate is fabricated from a dielectric material and the first and second coils are fabricated from a copper material.

17. A transformer assembly in accordance with claim 10 wherein the first and second coils include a plurality of turns that are coplanar.

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

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

forming a second spiral electrical inductor on the first surface of the substrate such that the first spiral inductor is interleaved with the second spiral inductor.

19. A method of fabricating a transformer assembly in accordance with claim 18 wherein forming a first spiral electrical inductor 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;

connecting the first spiral inductor portion to the second spiral inductor portion using a metallic pin.

20. A method of fabricating a transformer assembly in accordance with claim 18 further comprising:

forming at least one opening through the first and second spiral inductors; and

inserting a metallic pin into each of the openings.