Magnetic resonance system with transmission of a digitized magnetic resonance signal across an air gap

• US 8,258,787 B2
• Filed: 09/21/2009
• Issued: 09/04/2012
• Est. Priority Date: 09/22/2008
• Status: Active Grant

• Current Assignee: Siemens Healthineers AG (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Fischer, Hubertus, Renz, Wolfgang
• Primary Examiner(s): ARANA, LOUIS M
• Application Number:
  US12/563,331
• Publication Number:
  US 20100072997A1
• Time in Patent Office: 1,079 Days
• Field of Search: 324/318, 324/322, 324/300
• US Class Current: 324/318
• CPC Class Codes: G01R 33/3621 NMR receivers or demodulators, e.g. preamplifiers, means for frequency modulation of the MR signal using a digital down converter, means for analog to digital conversion [ADC] or for filtering or processing of the MR signal such as bandpass filtering, resampling, decimation or interpolation
• CPC Class Codes: G01R 33/3692 involving signal transmission without using electrically conductive connections, e.g. wireless communication or optical communication of the MR signal or an auxiliary signal other than the MR signal

Abstract

A magnetic resonance system has a patient receptacle and a base body. The patient receptacle has a subframe and a patient bed supported thereon so as to move a patient thereon through the base body. The base body has a basic field magnet system, a gradient system and an RF system that are operable to obtain an analog magnetic resonance signal from the patient. The patient receptacle has a signal conversion device composed of an A/D converter, a modulator, and a transmitter. The base body has a signal conversion device composed of a receiver and a demodulator. The A/D converter receives the magnetic resonance signal and digitizes it. The modulator modulates a carrier signal with the digitized magnetic resonance signal. The transmitter transmits the modulated carrier signal via an air gap to the receive. The receiver receives the transmitted carrier signal. The demodulator extracts the digitized magnetic resonance signal from the received carrier signal by demodulation and supplies it to an evaluation device for continuing evaluation.

Claims

1. A patient receptacle for a magnetic resonance system, said magnetic resonance system having a base body comprising a patient tunnel, and a base body signal conversion device, said patient receptacle comprising:

a subframe;

a patient bed supported by and movable on said subframe, said patient bed being adapted to receive a patient thereon, said subframe being positioned relative to said base body to convey on the patient bed through the patient tunnel by movement of the patient bed on the subframe;

said patient bed and said subframe forming a patient receptacle structure;

said patient receptacle structure comprising a local coil that acquires an analog magnetic resonance signal;

a patient receptacle signal conversion device located at said patient receptacle structure, said patient receptacle signal conversion device comprising an analog-to-digital converter, a modulator, and a transmitter;

said analog-to-digital converter being configured to receive the analog magnetic resonance signal acquired by the local coil and to convert the analog magnetic resonance signal into a digital magnetic resonance signal;

said modulator being configured to modulate a carrier signal with said digital magnetic resonance signal, to produce a modulated carrier signal; and

said transmitter being configured to transmit the modulated carrier signal via an air gap to said base body signal conversion device.

2. A patient receptacle as claimed in claim 1 wherein said transmitter comprises a transmission amplifier and a transmission antenna, and a band-limited gigahertz transmission link connecting an output of said transmission amplifier with said transmission antenna.

3. A patient receptacle as claimed in claim 1 comprising a pre-amplifier connected preceding said analog-to-digital converter.

4. A patient receptacle as claimed in claim 1 comprising RF shielding surrounding at least said analog-to-digital converter and said modulator.

5. A patient receptacle as claimed in claim 1 wherein said analog-to-digital converter and said modulator are located in said subframe.

6. A base body for a magnetic resonance system, said magnetic resonance system having a patient receptacle comprising a movable patient bed and a patient receptacle signal conversion device that emits a carrier signal modulated with a digitized magnetic resonance signal, said base body comprising:

a base body housing having a patient tunnel therein adapted to receive a patient on the patient bed of the patient receptacle;

a basic field magnet system configured to generate a static basic magnetic field in said patient tunnel;

a gradient system configured to generate gradient fields in said patient tunnel;

an RF system configured to radiate an RF excitation field in said tunnel that excites nuclei in the patient on the patient bed in the tunnel to magnetic resonance, so as to emit an analog magnetic resonance signal;

a signal conversion device in said housing, said signal conversion device comprising a receiver and a demodulator;

said receiver being configured to receive said carrier signal from said patient receptacle signal conversion device via an air gap, said digitized magnetic resonance signal with which said carrier signal is modulated corresponding to said analog magnetic resonance signal; and

said demodulator being configured to extract said digitized magnetic resonance signal from the received carrier signal and to supply the demodulated signal to an evaluation device for evaluation thereof.

7. A base body as claimed in claim 6 wherein said receiver comprises a reception antenna and a band-limited gigahertz transmission link connecting said reception antenna with an input of said demodulator.

8. A base body as claimed in claim 6 comprising RF shielding surrounding said demodulator.

9. A base body as claimed in claim 6 comprising a positioning aid configured to assist positioning of said patient receptacle at a predetermined position relative to said housing.

10. A base body as claimed in claim 6 comprising an RF shielded compartment in which said housing is contained, said RF shielded compartment having a size that also accommodates said patient receptacle.

11. A base body as claimed in claim 10 wherein said evaluation device is located outside of said RF shielded compartment.

12. A base body as claimed in claim 6 comprising an optical waveguide connected between said demodulator and said evaluation device, said demodulator supplying said demodulated digital magnetic resonance signal to the evaluation device via said optical waveguide.

13. A magnetic resonance system comprising:

a base body comprising a base body housing having a patient tunnel therein adapted to receive a patient on the patient bed of the patient receptacle;

a subframe;

a patient bed supported by and movable on said subframe, said patient bed being adapted to receive a patient thereon, said subframe being positioned relative to said base body to convey on the patient bed through the patient tunnel by movement of the patient bed on the subframe;

said base body comprising a basic field magnet system configured to generate a static basic magnetic field in said patient tunnel;

said base body comprising a gradient system configured to generate gradient fields in said patient tunnel;

said patient bed and said subframe forming a patient receptacle structure;

said patient receptacle structure comprising a local coil that acquires an analog magnetic resonance signal;

a patient receptacle signal conversion device located at said patient receptacle structure, said patient receptacle signal conversion device comprising an analog-to-digital converter, a modulator, and a transmitter;

said analog-to-digital converter being configured to receive the analog magnetic resonance signal acquired by the RF local coil and to convert the analog magnetic resonance signal into a digital magnetic resonance signal;

said modulator being configured to modulate a carrier signal with said digital magnetic resonance signal, to produce a modulated carrier signal;

said transmitter being configured to transmit the modulated carrier signal via an air gap to said base body signal conversion device;

said base body comprising a signal conversion device in said housing, said signal conversion device comprising a receiver and a demodulator;

said receiver being configured to receive said carrier signal from said patient receptacle signal conversion device via an air gap, said digitized magnetic resonance signal with which said carrier signal is modulated corresponding to said analog magnetic resonance signal; and

said demodulator being configured to extract said digitized magnetic resonance signal from the received carrier signal and to supply the demodulated signal to an evaluation device for evaluation thereof.

14. A magnetic resonance system as claimed in claim 13, wherein said air gap is less than one meter.

15. A magnetic resonance system as claimed in claim 13 wherein said air gap is less than 10 cm.