In a method and apparatus for three-dimensionally correcting distortions of an image dataset, a magnetic resonance device containing a basic field magnetic system for generating a basic magnetic field and a gradient system for generating gradient fields generates an image dataset and coefficients of a spherical function-series expansion of the basic magnetic field and/or of the gradient fields are used for the correction. Coefficients are thereby used, which have been determined, in the framework of a design and/or production procedure, forth basic field magnetic system and/or gradient system.