New Techniques in Low Level Fluoroscopy

In recent years a great deal of attention has been paid to the dangers of high X-ray dosage during fluoroscopic examination of a patient. A number of electronic devices have been put forth in an attempt to allow fluoroscopic image intensification and a consequent decrease in the required dosage. The purpose of this paper is to outline briefly the principles on which these devices work. The discussion begins with a general consideration of the requirements and limitations of fluorescent screen intensification. The devices which are then explained can be divided into four main categories: 1) solid-state intensifiers, 2) image-converter tube intensifiers, 3) television camera tubes directly sensitive to X radiation, 4) television camera systems with enhanced light sensitivity. Some general conclusions are drawn concerning the present state of the art in these devices.