Method and measuring apparatus for measuring a magnetic field in a field of view of a magnetic resonance facility

1 . A method for measuring a magnetic field in a field of view of a magnetic resonance facility, the method comprising:

providing a measuring apparatus comprising at least one magnetic field sensor;

measuring sensor data describing the magnetic field at measuring points on a measuring surface enclosing at least part of the field of view, wherein the measuring surface is a spherical surface; and

ascertaining magnetic field information that models the magnetic field three-dimensionally, at least within the field of view, from the sensor data,

wherein the measuring points are selected in a uniformly distributed sampling pattern for uniform sampling of an entirety of the measuring surface, and

wherein the measuring points on the measuring surface are determined as a Fibonacci lattice using a Fibonacci sphere algorithm.

2 . The method of claim 1 , wherein coefficients of a development according to harmonic functions are determined to ascertain the magnetic field information.

3 . The method of claim 2 , wherein the harmonic functions are solid harmonics.

4 . The method of claim 1 , wherein the field of view is selected as larger than a nominal field of view of the magnetic resonance facility and/or with a diameter that is at least 40 cm.

5 . The method of claim 4 , wherein the diameter is in a range of 50 cm to 70 cm.

6 . The method of claim 1 , wherein the magnetic field comprises a main magnetic field of a main magnet of the magnetic resonance facility, at least one gradient field of a gradient coil arrangement of the magnetic resonance facility, or a combination thereof.

7 . The method of claim 1 , wherein the measuring apparatus comprises a carrier component with the at least one magnetic field sensor, and

wherein the carrier component is moved successively to different measuring positions by a moving facility of the measuring apparatus to completely measure the measuring surface.

8 . The method of claim 7 , wherein the at least one magnetic field sensor comprises a plurality of magnetic field sensors,

wherein the carrier component has a carrier surface covering part of the measuring surface on which the plurality of magnetic field sensors is arranged in a uniformly distributed manner according to the uniformly distributed sampling pattern of the measuring points, and

wherein the carrier surface covers different portions of the measuring surface for the different measuring positions such that each measuring point is measured at least once.

9 . The method of claim 8 , wherein a shape of the carrier surface is selected such that a natural number of carrier surfaces are combined to form the entirety of the measuring surface, and

wherein a number of measuring positions corresponds to the natural number.

10 . A measuring apparatus for measuring a magnetic field in a field of view of a magnetic resonance facility, the measuring apparatus comprising:

a carrier component having at least one magnetic field sensor;

a moving facility configured to move the carrier component; and

a control facility configured to measure sensor data describing the magnetic field by uniformly sampling a measuring surface enclosing at least part of the field of view at a plurality of measuring points in a uniformly distributed sampling pattern on an entirety of the measuring surface by actuating the moving facility and the at least one magnetic field sensor,

wherein the measuring surface is a spherical surface, and

wherein the measuring points on the measuring surface are determined as a Fibonacci lattice using a Fibonacci sphere algorithm.

11 . The measuring apparatus of claim 10 , wherein the at least one magnetic field sensor comprises a plurality of magnetic field sensors, and

wherein the carrier component has a carrier surface covering at least part of the measuring surface on which the plurality of magnetic field sensors are arranged in a uniformly distributed manner according to the uniformly distributed measuring points.

12 . The measuring apparatus of claim 11 , wherein a shape of the carrier surface is selected such that a natural number of carrier surfaces are combined to form the entirety of the measuring surface.

13 . The measuring apparatus of claim 11 , wherein the moving facility has at least two rotation actuators for rotation about mutually perpendicular axes of rotation for positioning the carrier surface on the measuring surface.

14 . The measuring apparatus of claim 13 , wherein the moving facility has a further actuator configured to rotate the carrier surface with the plurality of magnetic field sensors about the carrier surface.

15 . The measuring apparatus of claim 14 , wherein an axis of rotation of the carrier surface runs through a center point of a surface of revolution.

16 . A measuring apparatus for measuring a magnetic field in a field of view of a magnetic resonance facility, the measuring apparatus comprising:

a carrier component having at least one magnetic field sensor;

a moving facility configured to move the carrier component; and

a control facility configured to measure sensor data describing the magnetic field by uniformly sampling a measuring surface enclosing at least part of the field of view at a plurality of measuring points in a uniformly distributed sampling pattern on an entirety of the measuring surface by actuating the moving facility and the at least one magnetic field sensor,

wherein the carrier component has a carrier surface covering at least part of the measuring surface,

wherein the moving facility has at least two rotation actuators for rotation about mutually perpendicular axes of rotation for positioning the carrier surface on the measuring surface, and

wherein the moving facility has a circular arc arm configured to rotate about a horizontal axis of rotation by a first rotation actuator of the at least two rotation actuators to which the carrier component is coupled via a guide block configured to be displaced by a second rotation actuator of the at least two rotation actuators, or

wherein the moving facility has a frame arm configured to rotate about the horizontal axis of rotation by the first rotation actuator of the at least two rotation actuators to which the carrier component is coupled at an end facing away from the first rotation actuator along the horizontal axis of rotation via the second rotation actuator of the at least two rotation actuators, and the frame arm defines a free space along the horizontal axis of rotation corresponding at least to a diameter of the measuring surface for rotating the carrier component by the second rotation actuator.

17 . The measuring apparatus of claim 16 , wherein the moving facility has the frame arm.

18 . The measuring apparatus of claim 16 , wherein the moving facility has the circular arc arm.