Radioisotope Ventriculography in Cats with Kaolin-Induced Hydrocephalus

Abstract

Movement of radioisotope from the ventricles in normal and kaolin-hydrocephalic cats was studied with a gamma camera. In hydrocephalic cats there was a progression of activity down the spinal axis reaching the region of the filum terminale within 20 minutes. Systemic absorption, assessed by appearance of activity in regions of the bladder and flank, was delayed when compared with normal cats. This delay corresponded to the time for the radioisotope to travel the length of the spine. This route of flow in hydrocephalic cats was shown by dye perfusion to be via the central canal and filum terminale to the spinal subarachnoid space. Other studies on kaolin-hydrocephalic cats proposing absorption of cerebrospinal fluid by the brain should be reconsidered.