Method and Curcuit Arrangement For Operating Multi-Channel Transmit/Receive Antenna Devices

• US 20080211501A1
• Filed: 04/21/2006
• Published: 09/04/2008
• Est. Priority Date: 04/28/2005
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Graesslin, Ingmar, Vernickel, Peter, Findeklee, Christian, Schmidt, Joachim
• Granted Patent: US 7,701,213 B2
• Time in Patent Office: Days
• US Class Current: 324/318
• CPC Class Codes: G01R 33/246 Spatial mapping of the RF magnetic field B1
• CPC Class Codes: G01R 33/3415 comprising arrays of sub-coils , i.e. phased-array coils with flexible receiver channels
• CPC Class Codes: G01R 33/5612 Parallel RF transmission, i.e. RF pulse transmission using a plurality of independent transmission channels
• CPC Class Codes: G01R 33/58 Calibration of imaging systems, e.g. using test probes , Phantoms; Calibration objects or fiducial markers such as active or passive RF coils surrounding an MR active material
• CPC Class Codes: G01R 33/583 Calibration of signal excitation or detection systems, e.g. for optimal RF excitation power or frequency G01R33/246 takes precedence

Abstract

Methods and circuit arrangements for operating multi-channel transmit/receive antenna devices or arrangements especially for use in magnetic resonance imaging (MRI) systems are disclosed, by which a fully independent control of complete multi-channel RF transmit and receive chains can be conducted in a flexible way and new options like RF shimming, transmit sensitivity encoding (TransmitSENSE), RF encoding, determination of S- or Z-matrix prior to spin echo measurements, calibration, SAR (specific absorption rate) reduction etc. can be utilized or improved.

Claims

1. Method for operating a multi-channel transmit/receive antenna device or arrangement comprising a plurality of RF antenna elements, wherein the steps of:

selecting which of one or more of the RF antenna elements transmit RF signals and/or which of one or more of the RF antenna elements receive RF signals and/or

controlling the amplitudes and/or the phases of the RF signals transmitted by the at least one transmitting RF antenna element individually and independently for each transmitting RF antenna element,

are conducted by controlling a plurality of transmit channels and/or receive channels which are each assigned to one of the RF antenna elements.

2. Method according to claim 1, wherein the steps of selecting and/or controlling the RF antenna elements is conducted in dependence of at least one level of RF signals which are received by means of at least one receiving RF antenna element which is positioned within the RF field generated by the antenna device or arrangement.

3. Circuit arrangement for operating a multi-channel transmit/receive antenna device or arrangement, especially for conducting a method according to claim 1, comprising a plurality of RF antenna elements, a control unit, a plurality of transmit channels and a plurality of receive channels which are each assigned to one of the antenna elements, wherein the control unit is provided for selecting antenna elements for transmitting RF signals and for selecting RF antenna elements for receiving RF signals and/or for controlling the transmit channels for individually adjusting the amplitudes and/or the phases of the transmitted RF signals.

4. Circuit arrangement according to claim 3, wherein the control unit is provided for said selecting of the antenna elements and/or for said controlling the transmit channels in dependence on at least one level of RF signals which are received by at least one pick-up/tune coil which is positioned within the RF field generated by the antenna device or arrangement.

5. Circuit arrangement according to claim 4, comprising a pick-up coil detection unit for processing and comparing received RF signals with at least one trip level.

6. Circuit arrangement according to claim 3, comprising a multi-channel RF amplifier or a plurality of one channel RF amplifiers which are controlled by the control unit in order to individually and independently amplify the transmit signals in each transmit channel.

7. Multi-channel amplifier or spectrometer, especially for use in a magnetic resonance imaging system, comprising a circuit arrangement according to claim 3.

8. Magnetic resonance imaging system, comprising a circuit arrangement according to claim 3.

9. Computer program comprising computer program code means adapted to perform a method according to claim 1 when said program is run on a programmable microcomputer.

10. Computer program according to claim 9 adapted to be downloaded to a magnetic resonance imaging system or one of its components when run on a computer which is connected to the internet.

11. Computer program product stored on a computer readable medium, comprising computer program code means according to claim 9.