<title>Image Intensification Fluoroscopy With Automatic Brightness Control</title>

Abstract

I appreciate the opportunity to chair this panel discussion and to introduce members of the panel. The topic for discussion is one of growing importance as automatic brightness control circuits are incorporated into an increasing number of image intensification fluoroscopic units. As most of you know, these circuits work by monitoring the brightness of the output phosphor of the intensifier or the current flowing from photocathode to anode in the intensifier, and using the resulting signal to adjust the tube voltage (kVp), tube current (mA), or tube voltage pulse width to maintain the output phosphor image at constant brightness. Automatic brightness control circuits are useful for routine fluoroscopy and essential if uniform densities are to be obtained from one frame to the next in cinefluorography. With the advent of 105 mm photospot filming as a replacement for conventional spot films, automatic brightness control circuits are being used in place of phototimers to obtain images of desired density.© (1975) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.