The invention relates to a method of determining a spatial distribution of magnetic particles in an examination area, in which a magnetic field is generated which has a first part-region having a relatively low magnetic field strength and a second part-region having a relatively high magnetic field strength. The position of the two part-regions is changed, as a result of which the magnetization in the examination area changes, and real measured values which depend on the change in magnetization are recorded. A dependence distribution which depends on a spatial distribution of magnetic particles is then determined such that a sum which comprises as summands a) the difference of the real measured values from fictitious measured values which are determined by applying a transfer function to the dependence distribution, and b) the product of a regularization parameter and of a regularization value which is determined by applying the regularization functional to the dependence distribution, is minimized. Finally, the spatial distribution of magnetic particles is determined by means of the determined dependence distribution.