Operating an MRI apparatus

Patent metadata

Field	Value
Publication number	US-11550009-B2
Application number	US-202117386533-A
Country	US
Kind code	B2
Filing date	Jul 27, 2021
Priority date	Aug 21, 2018
Publication date	Jan 10, 2023
Grant date	Jan 10, 2023

Abstract

A method of operating a magnetic resonance imaging (MRI) apparatus includes exciting a body coil of the MRI apparatus to emit a radio-frequency signal, determining a center frequency of a resonance curve of the body coil, and calculating a magnet target frequency based on the determined center frequency. A magnet is ramped to the magnet target frequency.

First claim

The invention claimed is:

1. A method of operating a magnetic resonance imaging (MRI) apparatus, the method comprising:
exciting a body coil of the MRI apparatus, such that a radio-frequency signal is emitted;
detecting a reflected radio-frequency signal;
determining a center frequency of a resonance curve of the body coil from the reflected radio-frequency signal;
identifying a magnet target frequency based on the determined center frequency; and
ramping a magnet to the magnet target frequency.

2. The method of claim 1 , further comprising storing the center frequency in a storage device of the MRI apparatus.

3. The method of claim 1 , wherein determining the center frequency comprises averaging the resonance curve of the reflected radio-frequency signal.

4. The method of claim 1 , wherein determining the center frequency comprises measuring transmissivity between the body coil and a further coil of the MRI apparatus.

5. The method of claim 1 , wherein ramping the magnet comprises ramping the magnet to a frequency comprising a sum of the magnet target frequency and an offset, and
wherein the offset is determined based on a ramping procedure.

6. The method of claim 1 , wherein determining the center frequency of the resonance curve of the body coil comprises determining the center frequency during manufacture of the MRI apparatus, at any time during a lifetime of the MRI apparatus, or during manufacture of the MRI apparatus and at any time during the lifetime of the MRI apparatus.

7. The method of claim 1 , wherein the target frequency of the magnet is determined in the absence of a main magnetic field.

8. A magnetic resonance imaging (MRI) apparatus comprising:
a body coil excitation unit configured to excite a body coil, such that a radio-frequency signal is emitted;
a processor configured to:
determine a center frequency of a resonance curve of a reflected radio-frequency signal; and
calculate a magnet target frequency based on the determined center frequency; and

a magnet power supply configured to ramp the magnet to the target frequency.

9. The MRI apparatus of claim 8 , wherein a field strength of the magnet of the MRI apparatus is at most 1.0 Tesla.

10. Then MRI apparatus of claim 8 , wherein the magnet is a superconductive magnet.

11. The MRI apparatus of claim 8 , wherein a bandwidth of the body coil comprises at most 100 kHz.

12. The MRI apparatus of claim 8 , further comprising a storage device configured to store the determined center frequency,
wherein the storage device is configured as part of the body coil, in a controller of the MRI apparatus, or as part of the body coil and in the controller of the MRI apparatus.

13. In a non-transitory computer-readable storage medium that stores instructions executable by one or more processors to operate a magnetic resonance imaging (MRI) apparatus, the instructions comprising:
exciting a body coil of the MRI apparatus, such that a radio-frequency signal is emitted;
detecting a reflected radio-frequency signal;
determining a center frequency of a resonance curve of the body coil from the reflected radio-frequency signal;
identifying a magnet target frequency based on the determined center frequency; and
ramping a magnet to the magnet target frequency.

Assignees

• Siemens Healthcare Gmbh

Inventors

• Biber Stephan
• Bampton Adrian
• Vester Markus
• De Oliveira Andre
• Model Volker
• Nistler Jürgen
• Potthast Andreas
• Johnstone Adam Paul

Classifications

• A61B5/055

  involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging · CPC title

• G01R33/54

  Signal processing systems, e.g. using pulse sequences {; Generation or control of pulse sequences; Operator console} · CPC title

• G01R33/446

  Multifrequency selective RF pulses, e.g. multinuclear acquisition mode (spatially selective RF pulses G01R33/4833) · CPC title

• G01R33/3815 Primary

  with superconducting coils, e.g. power supply therefor · CPC title

• G01R33/381 Primary

  using electromagnets · CPC title