Artefacts in MR images of electrical current distribution

Artefacts in images of electrical current distribution measured by magnetic resonance imaging (MRI) are presented. These artefacts, caused by the effects of the connecting cables used to apply the electrical current to the object during the MRI scan, can lead to an underestimation of the magnitude of the electrical current measured in the experiment. The size of this underestimate depends upon the experimental geometry, but in the experiments and simulations described here, performed with a cylindrical phantom approximately 8 cm long and 8 cm in diameter, the difference can be 27%. These artefacts are reduced if the connecting cables are rigidly fixed to the object so that the induced magnetic field is correctly measured during the MRI experiment.