Studies of the third circulation. Amipaque CT cisternography and ventriculography.

The techniques of Amipaque (metrizamide) computerized tomography (CT) cisternography and Amipaque CT ventriculography are described. Normal, intermediate, delayed, and obstructive cerebrospinal fluid circulation patterns are readily demonstrated by evaluation of ventricular stasis of Amipaque on serial CT scans. Both the morphological and physiological characteristics of intracranial cysts are accurately defined and a diagnostic classification is presented. The functional integrity of ventricular shunts can be appraised using the ventricular persistance of Amipaque as a primary criterion. Other applications of these modalities are described and their place in the neurodiagnostic armamentarium is discussed.