Magnetic resonance imaging system with RF motion detection

Abstract

The present invention is directed to a magnetic resonance imaging system with motion detection for examination of a patient (53), the magnetic resonance imaging system comprising an RF coil arrangement with an RF coil (4) for transmitting and/or receiving an RF signal for generating a magnetic resonance image wherein the RF coil arrangement is provided with an additional RF sensor (5) for transmitting an RF transmit signal which is adapted for interacting with the tissue (23) of the patient (53) allowing to sense motion signals due to motions of the patient (53) simultaneously to transmitting and/or receiving the RF signal for generating the magnetic resonance image. In this way movements of a patient under examination in an MRI system may be detected in an efficient and reliable way.

Claims

1. A magnetic resonance imaging system for examination of a patient, the magnetic resonance imaging system comprising: a radio frequency (RF) coil for transmitting and/or receiving an RF signal for generating a magnetic resonance image; a preamplifier connected with the RF coil; and an RF sensor for transmitting an RF transmit signal for interacting with tissue of the patient, and for receiving resulting motion signals due to motions of the patient simultaneously with the RF coil transmitting and/or receiving the RF signal for generating the magnetic resonance image, wherein the RF sensor is arranged together with the preamplifier, wherein the RF sensor comprises an antenna integrated into the RF coil, and wherein the RF transmit signal comprises a continuous-wave radar signal and/or an ultra wideband radar signal.

2. The magnetic resonance imaging system according to claim 1, wherein the preamplifier and the RF sensor form an integrated RF transceiver device for motion detection.

3. The magnetic resonance imaging system according to claim 2, wherein the integrated RF transceiver device is configured to generate a carrier signal which is a digital spread spectrum signal, and wherein the integrated RF transceiver device further comprises a decorrelator configured for removing spread spectrum signals from MRI signals such that the RF coil is simultaneously used for the MRI signals and additional RF signals for motion detection.

4. The magnetic resonance imaging system according to claim 1, wherein the RF sensor comprises an antenna located on a printed circuit board of the preamplifier.

5. The magnetic resonance imaging system according to claim 1, further comprising a machine-learning module with deep learning capability adapted for processing the received motion signals.

6. The magnetic resonance imaging system according to claim 5, wherein the machine-learning module is connected to the RF coil for receiving the RF signal for generating the magnetic resonance image.

7. The magnetic resonance imaging system according to claim 5, further comprising: an additional RF coil for transmitting and/or receiving an additional RF signal for generating a magnetic resonance image; an additional RF sensor for transmitting and receiving an additional RF transmit signal for interacting with the tissue of the patient, and for receiving resulting additional motion signals due to motions of the patient; and an additional machine-learning module for processing the additional motion signals, wherein the RF sensor and the additional RF sensor are separately connected to the machine-learning module and the additional machine-learning module, respectively, for processing the received motion signals and the received additional motion signals, respectively.

8. A method of operating a magnetic resonance imaging system for examination of a patient, the magnetic resonance imaging system comprising a radio frequency (RF) coil and an RF sensor, wherein the RF sensor comprises an antenna integrated into the RF coil, the method comprising: transmitting and/or receiving an RF signal for generating a magnetic resonance image by the RF coil using the RF coil; amplifying the RF signal using a preamplifier; transmitting an RF transmit signal for interacting with tissue of the patient using the RF sensor, wherein the RF sensor is arranged together with the preamplifier; and receiving motion signals which are due to motions of the patient, simultaneously with transmitting and/or receiving the RF signal for generating the magnetic resonance image, using the RF sensor, wherein the RF transmit signal comprises a continuous-wave radar signal and/or an ultra wideband radar signal.

9. The method of claim 8, further comprising: processing the received motion signals in a machine-learning module with deep learning capability.

10. The method of claim 9, further comprising: processing the received motion signals together with the RF signal for generating the magnetic resonance image in the machine-learning module.

11. A non-transitory computer-readable medium for controlling operation of a magnetic resonance imaging system for examination of a patient, the magnetic resonance imaging system comprising radio frequency (RF) coil and an RF sensor, wherein the RF sensor comprises an antenna integrated into the RF coil, the non-transitory computer-readable medium comprising instructions stored thereon, that when executed on a processor, cause the processor to: transmit and/or receive an RF signal for generating a magnetic resonance image by the RF coil using the RF coil; transmit an RF transmit signal for interacting with tissue of the patient using; the RF sensor, wherein the RF sensor is arranged together with a preamplifier; and receive motion signals which are due to motions of the patient, simultaneously with transmitting and/or receiving the RF signal for generating the magnetic resonance image, using the RF sensor, wherein the RF transmit signal comprises a continuous-wave radar signal and/or an ultra wideband radar signal.

12. The magnetic resonance imaging system according to claim 2, wherein the RF coil is configured as an antenna device by the integrated RF transceiver device in a multi resonant design.

13. The method of claim 8, wherein the preamplifier and the RF sensor form an integrated RF transceiver device, the method further comprising: generating a carrier signal, which is a digital spread spectrum signal, using the integrated RF transceiver device.

14. The method of claim 13, further comprising: removing spread spectrum signals from MRI signals such that the RF coil is simultaneously used for the MRI signals and additional RF signals for motion detection.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. Such an embodiment does not necessarily represent the full scope of the invention, however, and reference is made therefore to the claims and herein for interpreting the scope of the invention.

(2) In the drawings:

(3) FIG. 1 schematically depicts a preamplifier printed circuit board with an integrated RF transceiver device for motion detection according to a preferred embodiment of the invention,

(4) FIG. 2 schematically depicts a preamplifier printed circuit board with an integrated RF transceiver device for motion detection according to another preferred embodiment of the invention,

(5) FIG. 3 schematically depicts an RF coil array with integrated RF motion detectors according to a preferred embodiment of the invention,

(6) FIG. 4 schematically depicts RF coils with integrated RF motion detector antennas according to further preferred embodiments of the invention,

(7) FIG. 5 schematically depicts an RF coil antenna with integrated distributed stub antennas according to a preferred embodiment of the invention, and

(8) FIG. 6 schematically depicts a MRI system with multiple RF sensors in a patient bed according to a preferred embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

(9) From FIG. 1 schematically a preamplifier printed circuit board 1 with an integrated RF transceiver device 2 for motion detection and an RF coil 4 according to a preferred embodiment of the invention can be seen. This is an RF coil arrangement with an RF coil 4 for transmitting and/or receiving an RF signal for generating a magnetic resonance image wherein the RF coil arrangement is provided with an additional RF sensor for transmitting and receiving an RF transmit signal which is adapted for interacting with the tissue of a patient under examination allowing to sense motion signals due to motions of the patient simultaneously to transmitting and/or receiving the RF signal for generating the magnetic resonance image. The antenna 3 of the RF transceiver 2 is integrated in the RF coil 4 but may also be located on the printed circuit board 1. The RF coil 4 itself may also be used as antenna device by the RF transceiver device 2 in a multi resonant design. The printed circuit board 1 comprises a radar and RF sensor 5 including a digital modulator 9 and an amplifier 10 from where signals are fed to the antenna 3. Signals received by the RF coil 4 are fed to the preamplifier 6 and further to the digitizer and compressor 7. I/O functionality is realized by a digital interface 8.

(10) FIG. 2 schematically depicts a preamplifier printed circuit board with an integrated RF transceiver device 2′ for motion detection according to another preferred embodiment of the invention. The general design is similar to the design shown in FIG. 1 and like devices are referred to with like reference signs. However, here, a carrier signal is generated which is either outside the MRI band or is a digital spread spectrum signal. The spread spectrum signal is removed from the MRI signal via decorrelator 11. The RF coil 4 is simultaneously used for MRI and the additional RF signal for motion detection.

(11) An RF coil array with integrated RF motion detectors according to a preferred embodiment of the invention is schematically depicted in FIG. 3. Each individual coil 21 is equipped with a local motion detector device 22. The motion detector device 22 senses the motion in the tissue 23 of the patient, i.e. the motion of internal organs of the patient (heart, liver) or the body surface of the patient. The motion sensing field is referred to by reference sign 24. Either reflected wave or crosstalk between individual coil elements is used for further processing.

(12) FIG. 4 schematically depicts RF coils 4 with integrated RF motion detector antennas according to further preferred embodiments of the invention, i.e. a) an antenna array 41, b) a dipole antenna 42, and c) a spiral Vivaldi design antenna 43. In FIG. 5, schematically an RF coil antenna 4 with integrated distributed stub antennas 44 according to another preferred embodiment of the invention is depicted.

(13) According to a preferred embodiment of the invention, the MRI system 60 schematically depicted in FIG. 6 comprises a machine-learning module 51 with deep learning capability. FIG. 6 further shows a patient bed 52 for holding a patient 53 during MRI examination in an MRI bore 54 of the MRI system 60. The patient bed 52 comprises several RF sensors 55 for transmitting RF transmit signals which are adapted for interacting with the tissue of the patient 53 allowing to sense motion signals due to motions of the patient 53 simultaneously to transmitting and/or receiving the RF signal for generating the magnetic resonance image. The RF sensors 55 are controlled by a signal control and processing unit 56 which is coupled both to a MRI console 57 for operation by a user and the machine-learning module 51. The machine-learning module 51 receives the sensed motion signals and the RF signals for generating the magnetic resonance image.

(14) The machine-learning module 51 is identifying the relevant sensor attributes of the operating condition of the RF sensor 55, e.g. Motion of heart Motion of organs (respiration) Motion of body and extremities Posing of patient Weight of patient Electrical parameters (permittivity and loading) Reflected power Coil loading condition

(15) The signal control and processing unit 56 modifies the RF sensor coefficient setting continually and other parameters like the selection of sensors, frequency and antenna as the operating condition changes. The machine-learning module 51 monitors the present operating condition and, in response to abrupt changes, restores past coefficients that were successful under similar conditions beforehand.

(16) Successful coefficient settings are stored in a list that is indexed using a multi-dimensional attribute vector derived from the measured operating condition. Unlike look-up-tables with array structures, the list generates elements automatically. The size of the list is dynamic, growing, as more operating conditions are experienced and contracting as neighbouring elements are recognized as redundant.

(17) While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope. Further, for the sake of clearness, not all elements in the drawings may have been supplied with reference signs.

REFERENCE SYMBOL LIST

(18) Printed circuit board 1 Transceiver device 2 Antenna 3 RF coil 4 Additional RF sensor 5 Preamplifier 6 Digitizer and compressor 7 Digital interface 8 Digital modulator 9 Amplifier 10 Decorrelator 11 Coil 21 Motion-detecting device 22 Tissue 23 Antenna array 41 Dipole 42 Spiral Vivaldi design 43 Distributed stub antennas 44 Machine-learning module 51 Patient bed 52 Patient 53 MRI bore 54 RF sensors 55 Signal control and processing unit 56 MRI console 57 MRI system 60