US 12,436,218 B2
Magnetic resonance tomography unit and method for reducing image interference from low-frequency magnetic fields
Andrew Dewdney, Neunkirchen am Brand (DE)
Assigned to Siemens Healthineers AG, Forchheim (DE)
Filed by Siemens Healthcare GmbH, Erlangen (DE)
Filed on Nov. 11, 2023, as Appl. No. 18/507,050.
Claims priority of application No. 22206849 (EP), filed on Nov. 11, 2022.
Prior Publication US 2024/0159851 A1, May 16, 2024
Int. Cl. G01R 33/565 (2006.01); G01R 33/00 (2006.01); G01R 33/56 (2006.01); G01R 33/58 (2006.01)
CPC G01R 33/56563 (2013.01) [G01R 33/007 (2013.01); G01R 33/5608 (2013.01); G01R 33/583 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A magnetic resonance tomography unit comprising:
a controller; and
a plurality of magnetic field sensors arranged in an environment of the magnetic resonance tomography unit,
wherein the plurality of magnetic field sensors are configured to:
capture low-frequency magnetic fields in the environment of the magnetic resonance tomography unit; and
transmit information about the low-frequency magnetic fields to the controller via a signal connection,
wherein the controller is configured to:
change signal processing during image capture in dependence on the information about the low-frequency magnetic fields so that an influence of the captured low-frequency magnetic fields on image capture is reduced;
capture a magnetic field in the environment of the magnetic resonance tomography unit using the plurality of magnetic field sensors; and
ascertain a center frequency of a magnetic resonance signal for image acquisition in dependence on the captured magnetic field,
wherein the magnetic resonance tomography unit further comprises a variable-frequency oscillator in a receive path, the variable-frequency oscillator being configured to down-mix the magnetic resonance signal to an intermediate frequency, and
wherein the controller is further configured to set the variable-frequency oscillator in dependence on the ascertained center frequency in an image capturing region, such that the down-mixed magnetic resonance signal has a constant center frequency, thus compensating for an effect of an interfering magnetic field.