• Although computerized cranial tomography (CT) is useful for the diagnosis of hydrocephalus and various fluid-containing intracranial cysts, CT cannot always define the functional relationship of the cyst to the normal CSF pathways. In such cases, ventriculography may be necessary to determine proper treatment. Metrizamide, a nonionic water-soluble contrast medium, has been used for myelography and ventriculography in adults and for myelography in children. Eleven children have had ventriculograms using metrizamide with conventional roentgenographic techniques. Diagnostic information was obtained in all but one study. No major complications occurred.