FILM-SCREEN VS DIGITAL RADIOGRAPHY IN RHEUMATOID-ARTHRITIS OF THE HAND

In a prospective investigation the diagnostic accuracy of film-screen and digital radiography in rheumatoid arthritis of hands was compared. Seventy hands of 36 patients with established rheumatoid arthritis we re included in the study. Each of 11 joints in every hand was evaluate d regarding the following radiologic parameters: soft tissue swelling, joint space narrowing, erosions and periarticular osteopenia. The dig ital images were obtained with storage phosphor image plates and evalu ated in 2 forms; as digital hard-copy on film and on a monitor of an i nteractive workstation. The digital images had a resolution of either 3.33 or 5.0 lp/mm. ROC curves were constructed and comparing the area under the curves no significant difference was found between the 3 dif ferent imaging forms in either resolution group for soft tissue swelli ng, joint space narrowing and erosions. The film-screen image evaluati on of periarticular osteopenia was significantly better than the digit al hard-copy one in the 3.33 lp/mm resolution group, but no significan t difference was found in the 5.0 lp/mm group. These results support t he view that currently available digital systems are capable of adequa te diagnostic performance.