Auxiliary magnetic field production method for magnetic resonance diagnosis

摘要

The method produces a homogeneous stationary magnetic field, by which a small section is representative of the entire test area in a three-dimensional magnetic resonance examination. It can be achieved by use of an auxiliary magnetic field produced from at least three coils supplied by directable current. The main magnetic field is measured at a number of points in the area of examination. Section volumes in an MR sequence are received as MR signals and evaluated. These values are used to determine the current in the coils of the auxiliary magnet from which, in conjunction with the main magnet, optimal homogeneity in the entire magnetic field results. The system is particularly useful where, for example, the position of a probe in the patient's body changes in relation to the main magnetic field.