X ray findings of Rheumatoid Arthritis
The mnemonic ABCDE’S is a convenient way to remember these:
- A —Alignment, abnormal; no ankylosis
- B —Bones—periarticular (juxtaarticular) osteoporosis; no periostitis or osteophytes
- C —Cartilage—uniform (symmetric) joint space loss in weight-bearing joints; no cartilage or soft tissue calcification
- D —Deformities (swan neck, ulnar deviation, boutonnière) with symmetrical distribution
- E —Erosions, marginal
- S —Soft-tissue swelling; nodules without calcification.
The radiographic changes in RA take months to develop. Juxtaarticular osteopenia is seen early in the course of the disease, followed later by more diffuse osteopenia. Joint erosions typically occur at the margins of small joints. Later, joint space narrowing and deformities develop. The earliest erosions occur in the hands (2, 3, 5 MCPs) before the feet in one-third of patients; the feet (1, 5 MTPs) before the hands in one-third of patients; and in both hands and feet at the same time in one-third of patients. Magnetic resonance imaging (MRI) will show 40% more erosions than conventional radiography. However, a caveat is that MRI can show MCP and/or wrist erosions or synovitis in 2% and 9% of healthy individuals, respectively
