Device and method for generating excitation pulses

Patent metadata

Field	Value
Publication number	US-10830852-B2
Application number	US-201816204465-A
Country	US
Kind code	B2
Filing date	Nov 29, 2018
Priority date	Nov 30, 2017
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

A radio-frequency control system for a magnetic resonance tomography system and a method for the operation thereof are provided. The radio-frequency control system includes a controller and a radio-frequency power amplifier with amplification between a signal input and a signal output of the radio-frequency power amplifier that is dependent on a predetermined frequency response. The controller determines a control pulse for multislice excitation and outputs the pulse to the signal input of the radio-frequency power amplifier. The controller determines a high-frequency power value for the control pulse in dependence on the predetermined frequency response of the radio-frequency power amplifier.

First claim

The invention claimed is:

1. A radio-frequency control system for a magnetic resonance tomography system, the radio-frequency control system comprising:
a controller; and
a radio-frequency power amplifier with amplification between a signal input and a signal output of the radio-frequency power amplifier that is dependent on a predetermined frequency response,
wherein the controller is configured to:
determine a control pulse for multislice excitation;
output the control pulse to the signal input of the radio-frequency power amplifier; and
weight the control pulse with the predetermined frequency response of the radio-frequency power amplifier to determine a high-frequency power value for the control pulse in dependence on the predetermined frequency response of the radio-frequency power amplifier from the control pulse.

2. The radio-frequency control system of claim 1 , wherein the controller is further configured to weight a nominal control pulse for the generation of the control pulse with a function that is inverse to the predetermined frequency response.

3. The radio-frequency control system of claim 1 , further comprising a power meter in signal connection with the signal output of the radio-frequency power amplifier,
wherein the controller is configured to determine the predetermined frequency response on a change of patient.

4. The radio-frequency control system of claim 2 , further comprising a power meter in signal connection with the signal output of the radio-frequency power amplifier,
wherein the controller is configured to determine the predetermined frequency response on a change of patient.

5. The radio-frequency control system of claim 1 , wherein the controller is further configured to:
compare the determined high-frequency power value with a predetermined limit radio-frequency value; and
interrupt the output of the control pulse for multislice excitation to the signal input of the radio-frequency power amplifier when the limit radio-frequency value is exceeded by the high-frequency power value.

6. The radio-frequency control system of claim 2 , wherein the controller is further configured to:
compare the determined high-frequency power value with a predetermined limit radio-frequency value; and
interrupt the output of the control pulse for multislice excitation to the signal input of the radio-frequency power amplifier when the limit radio-frequency value is exceeded by the high-frequency power value.

7. The radio-frequency control system of claim 3 , wherein the controller is further configured to:
compare the determined high-frequency power value with a predetermined limit radio-frequency value; and
interrupt the output of the control pulse for multislice excitation to the signal input of the radio-frequency power amplifier when the limit radio-frequency value is exceeded by the high-frequency power value.

8. A method for operating a magnetic resonance tomography system, wherein the magnetic resonance tomography system comprises a radio-frequency control system, the radio-frequency control system comprising a controller and a radio-frequency power amplifier with amplification between a signal input and a signal output of the radio-frequency power amplifier that is dependent on a predetermined frequency response, the method comprising: determining, by the controller, a control pulse for multislice excitation; outputting the control pulse to the signal input of the radio-frequency power amplifier; determining a high-frequency power value for the control pulse in dependence on the predetermined frequency response of the radio-frequency power amplifier from the control pulse or a nominal control pulse that is independent of the predetermined frequency response, from which the control pulse is generated; and generating the control pulse, generating the control pulse comprising weighting, by the radio-frequency control system, the nominal control pulse with a function that is inverse to the frequency response.

9. The method of claim 8 , wherein determining the high-frequency power value comprises weighting, by the radio-frequency control system, the control pulse with the frequency response of the radio-frequency power amplifier.

10. The method of claim 8 , wherein the radio-frequency control system comprises a power meter in signal connection with the signal output of the radio-frequency power amplifier, and
wherein the method further comprises determining, by the power meter, the predetermined frequency response on a change of patient.

11. The method of claim 8 , further comprising:
comparing, by the radio-frequency control system, the determined high-frequency power value with a predetermined limit radio-frequency value; and
interrupting the outputting of the control pulse for multislice excitation to the signal input of the radio-frequency power amplifier when the limit radio-frequency value is exceeded by the high-frequency power value.

12. In a non-transitory computer-readable storage medium that stores instructions executable by a controller of a radio-frequency control system to operate a magnetic resonance tomography system, the magnetic resonance tomography system comprising the radio-frequency control system, the radio-frequency control system comprising a radio-frequency power amplifier with amplification between a signal input and a signal output of the radio-frequency power amplifier that is dependent on a predetermined frequency response, the instructions comprising: determining, by the controller, a control pulse for multislice excitation; outputting the control pulse to the signal input of the radio-frequency power amplifier; determining a high-frequency power value for the control pulse in dependence on the predetermined frequency response of the radio-frequency power amplifier from the control pulse or a nominal control pulse that is independent of the frequency response, from which the control pulse is generated; and generating the control pulse, generating the control pulse comprising weighting, by the radio-frequency control system, the nominal control pulse with a function that is inverse to the frequency response.

13. The non-transitory computer-readable storage medium of claim 12 , wherein determining the high-frequency power value comprises weighting, by the radio-frequency control system, the control pulse with the frequency response of the radio-frequency power amplifier.

14. The non-transitory computer-readable storage medium of claim 12 , wherein the radio-frequency control system comprises a power meter in signal connection with the signal output of the radio-frequency power amplifier, and
wherein the instructions further comprise determining, by the power meter, the predetermined frequency response on a change of patient.

15. The non-transitory computer-readable storage medium of claim 12 , wherein the instructions further comprise:
comparing, by the radio-frequency control system, the determined high-frequency power value with a predetermined limit radio-frequency value; and
interrupting the outputting of the control pulse for multislice excitation to the signal input of the radio-frequency power amplifier when the limit radio-frequency value is exceeded by the high-frequency power value.

16. A radio-frequency control system for a magnetic resonance tomography system, the radio-frequency control system comprising:
a controller;
a radio-frequency power amplifier with amplification between a signal input and a signal output of the radio-frequency power amplifier that is dependent on a predetermined frequency response; and
a powe

Assignees

• Siemens Healthcare Gmbh

Inventors

• Hölscher Uvo
• Stöcker Stephan
• WüNSCH CHRISTIAN

Classifications

• 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

• G01R33/3607

  RF waveform generators, e.g. frequency generators, amplitude-, frequency- or phase modulators or shifters, pulse programmers, digital to analog converters for the RF signal, means for filtering or attenuating of the RF signal · CPC title

• G01R33/288

  Provisions within MR facilities for enhancing safety during MR, e.g. reduction of the specific absorption rate [SAR], detection of ferromagnetic objects in the scanner room · CPC title

• G01R33/3614

  RF power amplifiers · CPC title

• G01R33/4835

  of multiple slices · CPC title