The rate of CSF formation in man: Preliminary observations on metrizamide washout as a measure of CSF bulk flow

Abstract

Metrizamide, a nonionic, water-soluble contrast agent, was injected into the ventricular system of 3 patients with indwelling ventricular catheters and subcutaneous cerebrospinal fluid reservoirs. A first-order rate constant, k, for metrizamide washout from the right lateral ventricle was determined with reference to mean ventricular metrizamide concentration on serial CAT scans; right ventricular volume, V, was estimated after metrizamide injection by multiplying the appropriate ventricular area on consecutive CAT slices by the nominal slice thickness. The rat of right lateral ventricular CSF formation, I_f, in our 3 patients was calculated as k × V and ranged from 0.83 to 0.103 ml per minute.