In a magnetic resonance method and system to determine a position of a slice relative to a region moving relative to the slice within a predetermined volume segment of an examination subject located in the magnetic resonance system, a physical property within the slice is detected with spatial resolution at multiple points in time, such that a time curve of the physical property is detected for at least one voxel of the slice. The position of the slice relative to the region is determined with respect to defined points in time, depending on the time curve.