en·ceph·a·log·ra·phy 
(ĕn-sĕf′ə-lŏgrə-fē)
(ĕn-sĕf′ə-lŏgrə-fē)n. pl. en·ceph·a·log·ra·phies
Radiographic examination of the brain in which some of the cerebrospinal fluid is replaced with air or another gas that acts as a contrast medium.
en·ceph′a·lo·graphic (-ə-lə-grăfĭk, -ə-lō-) adj.
en·ceph′a·lo·graphi·cal·ly adv.