Metrizamide cisternography in the investigation of the empty sella syndrome.

Pneumoencephalography, the usual method for demonstrating air within the sella turcica in empty sella syndrome (ESS), has been approached with reluctance by most physicians because of its technical difficulty and patient morbidity. For these reasons, neuroradiologists have investigated other contrast media in search of an ideal agent; metrizamide seems to be such an agent. Metrizamide is a nondissociable, water-soluble glucose amide containing three iodine molecules. This agent is miscible with CSF, and small recesses of the CSF-brain interface can be delineated with hypocycloidal tomography without performing cumbersome patient maneuvers to fill the cisterns. Furthermore, morbidity has been minimal, particularly with use of lower concentrations of metrizamide, allowed by the sensitivity of computerized tomographic (CT) scanning. Thus, at the present time, metrizamide cisternography (especially in conjunction with CT scanning) appears useful in evaluating an enlarged sella turcica, particularly when considering an entity such as ESS.