Localization of Radio-Active Implants with Image Intensification and Television

Abstract

A biplane fluoroscope fitted with an industrial television chain was developed for use in the localization of radioactive material during implantation of the pituitary gland of patients. An image intensifier was used which employs an electron optical tube consisting essentially of two fluorescent screens with a high potential difference between them. When x rays strike the front screen, they fluoresce in the normal manner. Electrons are emitted from the posterior surface in direct proportion to the amount of fluorescence immediately in front. The negatively charged particles are accelerated across to the anode end of the tube and are focused on the smaller screen at the rear. Owing to the difference in the areas of the two screens and the impact with which the electrons strike the smaller, its brightness is several hundred times greater than that of the other. With the aid of a simple optical attachment, it is possible for the observer to use smaller amounts of x rays and at the same time see the image in greater detail. The clinical examination can be carried out in a fully-lighted room. An industrial television chain was adapted for use in conjunction with the image intensifier for the benefit ofmore » the operating-room audience. (C. H.)« less