SUPPORT LINE AND TUBE VISIBILITY IN CHEST EXAMINATIONS USING COMPUTEDRADIOGRAPHY

The visibility of support lines and tubes was compared in computed rad iography (CR) and screen-film adult chest radiographs, Parameters inve stigated were radiation dose, image minification, and the use of unsha rp mask enhancement. Five radiologists rated the visibility of support lines and tubes on a five-point scale ranging from 1 (entire course o f Line visible) to 5 (line not visible or only small portion seen), Th ese CR results were compared with the visibility of support lines and tubes as assessed by the same readers for conventional screen-film rad iographs (600 speed). Support line and tube visibility improved with i mage enhancement, image minification, and increasing radiation dose. A t the same radiation exposure, support: line and tube visibility of th e screen;film combination was superior to that of standard GR images, Application of an unsharp mask enhancement algorithm to CR images, how ever, significantly improved support line and tube visibility in compa rison to that obtained with the screen-film combination, It was conclu ded that unsharp mask processing is a valuable tool for improving the visibility of support lines and tubes in CR chest radiographs. Copyrig ht (C) 1997 by W.B. Saunders Company.