 By this method, functional information from SPECT or positron emission tomography can be related to anatomical information provided by magnetic resonance imaging (MRI).Similarly, fiducial points established during MRI can be correlated with brain images generated by magnetoencephalography to localize the source of brain activity.Such fiducial points or markers are often created in tomographic images such as computed tomography, magnetic resonance and positron emission tomography images using devices such as the N-localizer and Sturm-Pastyr localizer.