Conventional radiography in rheumatoid arthritis: new scientific insights and practical application

Rheumatoid arthritis (RA) is a chronic systemic disease of unknown origin that predominantly involves synovial tissue. RA affects 0.5% of the global population, with a clear predilection for women. Conventional radiography (plain radiographs or X-rays) is the most widely used imaging technique for diagnosing and monitoring the progression of RA. Advanced imaging techniques (e.g. magnetic resonance imaging, computed tomography, ultrasound, and nuclear scintigraphy), that are better suited for detecting soft-tissue inflammation are available, but they are more costly and some of them may expose the patient to higher doses of radiation. Plain film radiographs are inexpensive, easy to generate, can be compared with baseline and prospective films, and provide a permanent, reproducible record. The plain radiographs of the hands and feet can detect the features that are specific to RA such as joint space narrowing or erosions, and serial radiography can be used as a objective marker for monitoring treatment response in clinical trials. This review discusses the use of conventional radiography for diagnosing and detecting early structural changes in joints and providing a historical overview of commonly used methods of scoring radiographs in RA.