Fractional Encephalography

Abstract

The principle of fractional encephalography is the following: the endocranial cavities containing the cerebrospinal fluid (CSF) are studied radiologically by injection of moderate amounts of a gaseous contrast medium, usually air. The study is “fractional,” i.e. the air, the volume of which is less than that of the ventricular system and the subarachnoid space, fills the different portions of these structures separately; the air is directed by suitable maneuvers on the principle that gas has an upward movement in fluids. These maneuvers consist of special variations in the body and head positions. The fundamental technique consists in letting the examination progress without necessarily following a set procedure in every case. In other words, as the first images (radiographic or televised) are examined, the operator decides how to continue, i.e. how to perform maneuvers and projections. The examination procedure depends on the condition of the patient, like any other clinical examination.