US 12,345,789 B2
Method for updating a magnetic field map during a MRI examination
Vidya MS, Bangalore (IN); Umesh Suryanarayana Rudrapatna, Bangalore (IN); Vijayananda Jagannatha, Bangalore (IN); Ashvin Srinivasan, Bengaluru (IN); Jaladhar Neelavalli, Bengaluru (IN); Sharun S Thazhackal, Bangalore (IN); and Suja Saraswathy, Bangalore (IN)
Assigned to Koninklijke Philips N.V., Eindhoven (NL)
Appl. No. 18/270,250
Filed by KONINKLIJKE PHILIPS N.V., Eindhoven (NL)
PCT Filed Dec. 29, 2021, PCT No. PCT/EP2021/087755
§ 371(c)(1), (2) Date Jun. 29, 2023,
PCT Pub. No. WO2022/148697, PCT Pub. Date Jul. 14, 2022.
Claims priority of application No. 21150639 (EP), filed on Jan. 8, 2021.
Prior Publication US 2024/0118360 A1, Apr. 11, 2024
Int. Cl. G01R 33/565 (2006.01); G01R 33/3875 (2006.01)
CPC G01R 33/56509 (2013.01) [G01R 33/3875 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method for updating a magnetic field, B0, map during a magnetic resonance imaging (MRI) examination of a subject or during reconstruction, comprising:
obtaining an initial B0 map of the subject associated with a start of the MRI examination;
obtaining motion data of the subject during the MRI examination; and
determining a motion-updated B0 map of the subject based on a B0 prediction model, the initial B0 map of the subject, and the motion data, wherein the B0 prediction model is configured to model changes in a B0 map as a fit of motion parameters of the subject, and wherein changes in the B0 map are approximated by a set of spherical harmonic coefficients wherein the changes in the B0 map comprise global changes generic across different subjects, and local changes specific to each subject, and wherein determining the motion-updated B0 map comprises:
determining the global changes to the initial B0 map of the subject based on the spherical harmonic coefficients which are lower order, and the motion data; and
determining the local changes to the initial B0 map of the subject based on the spherical harmonic coefficients which are higher order, and the motion data.