mag·ne·to·en·ceph·a·log·ra·phy 
(măg-nē′tō-ĕn-sĕf′ə-lŏgrə-fē)
(măg-nē′tō-ĕn-sĕf′ə-lŏgrə-fē)n. Abbr. MEG
A diagnostic imaging technique that detects and records magnetic fields produced by electrical activity in the brain.
mag·ne′to·en·ceph′a·lo·graphic (-ə-lə-grăfĭk, -ə-lō-) adj.