Measurement of radiographic changes occurring in rheumatoid arthritis by image analysis techniques.

We have applied image analysis techniques to serial measurements of bone contour in standard radiographs of single small joints of the hands in subjects with rheumatoid arthritis (RA) and controls. Adequate reproducibility was shown in 20 controls radiographed twice over a six month period. The technique showed significant changes in a proximal interphalangeal joint of 13 of 15 patients with RA studied over periods of three to 10 months. In further serial studies in selected small joints of RA hands significant changes could be shown as early as four months. These results justify further development of these techniques to allow their full scale evaluation in multiple joints in patients with RA receiving long term drug therapy.