The dipole density plot (DDP), a technique to show concentrations of dipoles

To analyse spontaneous multichannel slow-wave MEG activity a tool was developed to extract focal abnormal activity with a higher spatial dipole density across time. The first version works on discrete volume units, the second version avoids a possible location error, works continuously and can be adjusted for individual slices three-dimensionally. The first version is used for screening and the second version is used to go into more detail. The dipole density plot (DDP) is not limited to single foci, nor to the single-dipole model; neither is it limited to the MEG. The DDP seems to be a valuable tool for detecting and locating lesions three-dimensionally within the brain.