Physics, Techniques and Procedures

Air encephalography

an obsolete radiographic examination of the basal cisterns and ventricles of the brain, performed by filling the intracranial cerebrospinal fluid (CSF) spaces with air. Air was normally introduced through a lumbar puncture with the patient in a sitting position. Less commonly, a cisternal puncture was used. After adequate filling of the ventricles (usually with 2030 ml air), the needle was withdrawn, and the patient was rotated into various positions for air filling of all parts of the ventricular system (Fig.1). Specialized tomographic equipment allowed sections to be made in both the horizontal and vertical direction. The method was abandoned after the introduction of CT.

HJS

Fig.1

dAP view of the skull shows air-filled ventricles (arrow). (Courtesy of Dr. I.O. Skalpe, Rikshospitalet University Hospital, Oslo, Norway.)

Air encephalography, Fig.1