Effect of Injections of Colloidal Thorium Dioxide on the Ventricles and Subarachnoid Spaces

In the course of studies¹on the use of colloidal thorium dioxide as an agent for ventriculography a number of surgical and pathologic specimens have been obtained, from which some conclusions may be drawn concerning the effects produced by the injection of this foreign substance. As far as I am aware, there have been no similar studies of the results in man, and the studies on dogs reported by Alexander, Jung and Lyman²were made after the intraventricular injection of an unstabilized and unbuffered colloidal suspension of thorium dioxide. In view of the remarkable ventriculograms obtained after the injection of colloidal thorium dioxide, information is desirable to indicate whether the method is a safe one for more extensive use. The material on which I am reporting consisted of two specimens obtained for biopsy and material from eight autopsies, the time of securing of which ranged from one hour