An apparatus for detecting and repairing a ring artifact in a multi-spectral magnetic resonance image includes an image processor, which is configured to obtain an off-resonance magnetic field map and a deblurred composite image, to calculate a spatial gradient of the image based on the magnetic field map, to kernel search the spatial gradient, to mask the image, based on the kernel search, in order to identify voxels affected by a ring artifact, and to apply a filter in order to smooth intensities of the voxels identified by the image mask.