RADIO FREQUENCY COIL-ARRAY FOR MAGNETIC RESONANCE EXAMINATION SYSTEM

• US 20180364319A1
• Filed: 12/08/2016
• Published: 12/20/2018
• Est. Priority Date: 12/08/2015
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: VERNICKEL, PETER, FINDELKEE, CHRISTIAN, LEUSSLER, CHRISTOPH
• Granted Patent: US 10,641,851 B2
• Time in Patent Office: Days
• 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

A radio frequency (RF) coil array with multiple RF coil elements for a magnetic resonance examination system is disclosed. The decoupling of RF coil elements involves sets (pairs) of transformers and may also include geometrical overlap of adjacent coils. The mutual coupling between the transformers is adjustable. This provides additional degrees of freedom to fully decouple the RF coil elements from each other.

Claims

1. A radiofrequency (RF) coil array comprising:

multiple RF coil elements,

sets, in particular pairs, of transformers arranged between adjacent RF coil elements and

transformers of said sets having a mutual coupling which compensates for a mutual coupling between the adjacent RF coil elements.

2. An RF coil array as claimed in claim 1, wherein

the mutual coupling between transformers of a set is adjustable.

3. A radio-frequency coil array as claimed in claim 1 wherein:

the multiple coils arranged in a two-dimensional pattern that is spanned by a first and a second principal axis,

mutually transverse diagonal axes each having an orientation between the first and second principal axes,

a first transformer decoupling the coils offset along the first diagonal axis,

a second transformer decoupling the coils offset along the second diagonal axis, wherein the first and second transformers are coupled to compensate coupling between coils offset along the second principal axis.

4. A radio frequency coil array as claimed in claim 1, wherein there is geometrical overlap between coils offset along the first principal axis.

5. A radio frequency coil array as claimed in claim 1 wherein three or more coils meet at a single position and the first and second transformer are located at said meeting position to mutually decouple said three or more coils.

6. A radio-frequency coil array as claimed in claim 1, wherein

the first and second transformers each have an elongate transformer core and

the transformer cores being orientated at an adjustable angle which affects direct coupling between the transformers.

7. A radio frequency coil array as claimed in claim 1, wherein the transformer windings of the first and second transformers are spatially separated over and adjustable distance which affects direct coupling between the transformers.

8. A radio frequency coil array as claimed in claim 5, wherein the transformer windings are planar windings.

9. A radio frequency coil array as claimed in claim 3, wherein

the first transformer includes two sub-windings around a common first core and mutually displaced along the length of the common core,

the second transformer is formed by a single winding around a second core, and the second winding mounted tiltable with respect to the two sub-windings of the first transformer and

the first transformer decoupling one pair of coils from the third coil and the second transformer mutually decoupling the coils of said pair.

10. A radio-frequency coil array as claimed in claim 1, wherein discrete coupling elements, in particular capacitors, inductors of transmission lines, generate coupling between the transformers.

11. A method of decoupling coils in a radio frequency array as claimed in claim 1 comprising the steps of:

arranging the coils in a pre-determined two-dimensional pattern,

decouple coil elements that are mutually offset along a diagonal axis,

orientate or mutually displace the first and second transformers to compensate coupling between coils offset along the second principal axis.

12. A method of decoupling coils in a radio frequency array of claim 7 including to adjust geometrical overlap between coils offset along the first principal axis.