SELENIUM-BASED DIGITAL RADIOGRAPHY OF THE CHEST - RADIOLOGISTS PREFERENCE COMPARED WITH FILM-SCREEN RADIOGRAPHS

OBJECTIVE. A new digital thoracic radiography system (Thoravision; Phi lips Medical Systems, Hamburg, Germany), which uses selenium as a dete ctor material, was evaluated for observer preference. The system has b een shown to have higher detection efficiency than conventional film-s creen systems and thus could provide an image with reduced noise. The hypothesis tested in this study was that the selenium-based digital sy stem would provide an image appearance for conventional thoracic imagi ng that would be equal or superior to that provided by a conventional film-screen system. MATERIALS AND METHODS. Fifty-three patient volunte ers were imaged at 120 kV with both the selenium-based system and a th oracic film-screen combination system (InSight HC; Kodak, Rochester, N Y). Posteroanterior and lateral images were acquired with both systems , for a total of 212 images. Both imaging systems included a stationar y 12:1 antiscatter grid. Exposures were the same for both imaging syst ems, and the digital images were printed to film. Images for the same patient were compared by six observers-three specialized chest radiolo gists and three general radiologists. Images included both normal ches t radiographs and radiographs with abnormal findings. Each pair of ima ges was ranked on a scale from 1 to 5 for preference of technique, wit h a score of 3 indicating no preference. Eleven anatomic features were evaluated in the posteroanterior views, and six features were evaluat ed in the lateral views. Statistical significance of preference was ev aluated with Student's t test. RESULTS. The chest radiologists had a s tatistically significant preference for the serenium-based system for all 17 features (p < .001). The general radiologists had a statistical ly significant preference for the selenium-based system for visualizat ion of 10 of the 17 features (p < .05). Neither group had a statistica lly significant preference for the conventional images in any category .CONCLUSION. The selenium-based system provided an image appearance th at was significantly preferred by all radiologists, more strongly by t hose specializing in chest radiography. This study demonstrates that a digital thoracic imaging system can routinely produce images that are perceived as equal or superior to conventional images.