Patent ID: 6867590

Claim:
A method of compensating for eddy currents induced by the switching on and off magnetic fields in gradient coils in NMR imaging apparatuses, which method includes at least one compensation cycle comprising the following steps: a) Performing at least one detection of the magnetic field generated by the current flowing in a gradient coil, i.e., a gradient field b) Extrapolating the course of the effectively generated gradient field from the data of said at least one detection; c) Generating a gradient fields excitation current compensating eddy current effects on the gradient fields on the basis of a comparison of the effectively generated gradient fields and of a target gradient field; wherein at least a second compensation cycle is provided which comprises the following additional steps: d) comparing the effectively generated gradient field after the first compensation cycle with the target gradient field by determining the difference between the target gradient field and the effectively generated gradient field; e) defining a new fictive field by adding the difference defined at d) between the target gradient field and the effectively generated gradient field to the effectively generated field measured before having carried out the first compensation cycle and calculating from the new fictive field the currents needed for generating a new compensated gradient field.