Automated impedance adjustment of a multichannel rf coil assembly

Patent metadata

Field	Value
Publication number	US-2017371012-A1
Application number	US-201615542966-A
Country	US
Kind code	A1
Filing date	Jan 6, 2016
Priority date	Jan 21, 2015
Publication date	Dec 28, 2017
Grant date	—

Abstract

The present invention provides a multichannel radio frequency (RF) receive/transmit system ( 200 ) for use in an magnetic resonance (MR) imaging system ( 110 ), comprising a RF coil array ( 202 ) with multiple RF coil elements ( 204 ) for emission and reception of RF signals, whereby each RF coil element ( 204 ) is provided with tuning means ( 206 ), and a tuning/matching circuit ( 208 ) for comparing forward power provided to at least one of the RF coil elements ( 204 ) with reflected power at the respective RF coil element ( 204 ) of the at least one of the RF coil elements ( 204 ), and for tuning the at least one of the RF coil elements ( 204 ) based on a comparison of the forward power and the reflected power at least one of the RF coil elements ( 204 ). The present invention further provides a magnetic resonance (MR) imaging system ( 110 ) comprising the above multichannel RF receive/transmit system ( 200 ). Still further, the present invention further provides methods for performing magnetic resonance (MR) imaging using the above MR imaging system ( 110 ).

First claim

1 . A multichannel radio frequency (RF) receive/transmit system for use in an magnetic resonance (MR) imaging system, comprising:
a RF coil with multiple RF coil elements for emission and reception of RF signals, whereby each RF coil element is provided with tuning means, and a tuning/matching circuit for comparing forward power provided to at least one of the RF coil elements with reflected power at the respective RF coil element of the at least one of the RF coil elements and for tuning the at least one of the RF coil elements based on a comparison of the forward power and the reflected power at least one of the RF coil elements, the multichannel RF receive/transmit system additionally comprising at least one RF amplifier for driving the RF coil array, and the tuning/matching circuit comprising RF signal generating means for providing a RF signal to the at least one RF amplifier.

2 . The multichannel RF receive/transmit system according to any of claim 1 , wherein
the tuning/matching circuit comprises multiplexing means, which are connected to the RF coil elements for multiplexing the forward and reflected power of multiple RF coil elements.

3 . The multichannel RF receive/transmit system according to claim 1 , wherein
the RF coil array is provided integrally with the tuning/matching circuit.

4 . The multichannel RF receive/transmit system according to claim 1 , wherein
the tuning/matching circuit comprises a look-up table with tuning settings depending on a load.

5 . The multichannel RF receive/transmit system according to claim 1 , wherein
the tuning/matching circuit comprises input means for receiving input in respect to the load.

6 . The multichannel RF receive/transmit system according to claim 1 , comprising
at least one marker for marking a position of the multichannel RF receive/transmit system, in particular for marking a position of the RF coil array.

7 . A magnetic resonance (MR) imaging system comprising a multichannel RF receive/transmit system according to claim 1 .

8 . The MR imaging system according to preceding claim 8 , comprising:
monitoring means for detecting a movement of a load located within a bore of the MR imaging system, whereby the monitoring means are connected to the tuning/matching circuit of the multichannel RF receive/transmit system, and the monitoring means are adapted to provide movement information of the load to the tuning/matching circuit.

9 . The MR imaging system according to claim 7 , wherein
the monitoring means for detecting a movement of a load located within a bore of the MR imaging system comprise at least one camera.

10 . A method for performing magnetic resonance (MR) imaging using the MR imaging system according claim 7 , comprising the steps of:
tuning the RF coil array by providing forward power to at least one RF coil element of the RF coil array, comparing the forward power and the reflected power at the respective RF coil element of the at least one of the RF coil elements, and tuning the at least one of the RF coil elements based on a comparison of the forward power and the reflected power at least one of the RF coil elements, performing MR data acquisition, verifying if imaging quality is sufficient, and performing repeated tuning if imaging quality is not sufficient and providing a RF signal from the tuning/matching circuit to the at least one RF amplifier.

11 . A method for performing magnetic resonance (MR) imaging using the MR imaging system according to claim 8 , comprising the steps of:
performing a pre-tuning step for evaluating tuning settings for the RF coil array based on different positions of the load within a bore of the MR imaging system and based on a comparison of forward power and reflected power of at least one of the RF coil elements of the RF coil array, starting a MR imaging sequence, monitoring movement of the load within the bore of the MR imaging system, and continuously performing tuning of the RF coil array under consideration of the movement of the load within the bore as monitored.

12 . The method for performing MR imaging according to preceding claim 11 , comprising the steps of:
storing the evaluated tuning settings of the pre-tuning step with reference to a particular load, and loading the stored tuning settings of the pre-tuning step with reference to the load particular prior to starting a MR imaging sequence.

13 . The method for performing magnetic resonance (MR) imaging according to claim 1 , comprising the steps of:
evaluating the size of the load, and performing a tuning of the RF coil array under consideration of the size of the load.

Assignees

• Koninklijke Philips Nv

Inventors

• Leussler Christoph
• Vernickel Peter

Classifications

• G01R33/3415

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

• G01R33/3628 Primary

  Tuning/matching of the transmit/receive coil · CPC title

• G01R33/5659

  caused by a distortion of the RF magnetic field, e.g. spatial inhomogeneities of the RF magnetic field (G01R33/56509, G01R33/56518, G01R33/56536 take precedence) · CPC title

• G01R33/283

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

• G01R33/56509

  due to motion, displacement or flow, e.g. gradient moment nulling (G01R33/567 takes precedence) · CPC title