Balancing out a field inhomogeneity in a magnetic resonance tomography system and shim coil arrangement

摘要

In order to balance out a field inhomogeneity, a value for a coil current is determined by a controller as a function of an item of information relating to the field inhomogeneity and an item of information relating to a position of at least one balancing or shim coil arranged in the magnetic field. The value is to be supplied to the at least one shim coil in order to generate a magnetic balancing field to balance out the field inhomogeneity. A control signal for at least one shim current source and for at least one switching matrix coupling the at least one shim current source to the at least one shim coil is generated as a function of the at least one value.

主权项

1. A magnetic resonance tomography (MRT) system comprising:
a controllable switching matrix; a controller that generates a control signal as a function of information relating to a field inhomogeneity of a magnetic field of the MRT system; and a plurality of controllable shim current sources coupled to the controller, wherein each controllable shim current source of the plurality of controllable shim current sources generates a coil current as a function of the control signal, wherein the plurality of shim current sources is coupled to a plurality of shim coil connections via the controllable switching matrix, wherein at least two shim current sources of the plurality of shim current sources are combined and supplied at a same time to one shim coil connection of the plurality of shim coil connections, wherein a number of shim coil connections in the plurality of shim coil connections is greater than a number of shim current sources in the plurality of shim current sources, and wherein at least one shim coil is connectable to each shim coil connection of the plurality of shim coil connections in order to generate a magnetic balancing field.