Isotope Encephalography: Experience with 100 Cases.

Isotopes have been used for the detection and location of intracranial lesions since 1948 (Moore, 1948). In 1947 Moore demonstrated that fluorescein injected intravenously was selectively absorbed by gliomas (astrocytomas) and other tumours. When an ultraviolet light was shone on the exposed brain, a glioma reaching the surface reflected a different colour-yellow -from the remainder of the brain. Moore argued that if sodium diiodofluorescein tagged with 13 I was injected intravenously it should be possible with the aid of a Geiger-Muller counter to detect brain tumours through the intact skull. In this he was successful. Since then a large number of isotopes have been used for this purpose, and the apparatus designed for the detection of the emitted radiation has become more and more sensitive and sophisticated. Many neurological centres, particularly in the United States,