Radiographic Views for Suspected Rheumatoid Arthritis
For a woman aged 30-60 with suspected rheumatoid arthritis, obtain posteroanterior (PA) radiographs of both hands and both feet as the initial imaging study. 1
Initial Imaging Approach
Start with conventional radiography (plain X-rays) of the hands and feet bilaterally. This is the EULAR-recommended first-line imaging modality with a strength of recommendation of 9.0 out of 10. 1, 2 The specific views should include:
- Posteroanterior (PA) views of both hands including the wrists 2, 3, 4
- Anteroposterior (AP) views of both feet 2, 3
These radiographs establish baseline structural damage, document erosions, joint space narrowing, and periarticular osteoporosis—the classic radiographic hallmarks of RA. 1, 5
Why These Specific Joints Matter
The hands (particularly wrists, metacarpophalangeal joints, and proximal interphalangeal joints) and feet are the primary sites where RA manifests radiographically. 2 The feet, especially the fifth metatarsophalangeal joint, typically show erosions earlier and more frequently than hand joints. 3 Including both anatomic regions captures the full spectrum of early disease and provides the most complete baseline assessment. 3
When to Add Advanced Imaging
If plain radiographs are negative but clinical suspicion remains high, consider ultrasound or MRI as adjunctive studies—not as replacements for initial radiography. 1, 2
- Ultrasound detects synovitis 2.18-fold more frequently than clinical examination and improves diagnostic certainty (strength of recommendation 9.1). 6, 1 It is particularly useful when diagnostic doubt persists after normal X-rays. 1
- MRI detects synovitis 2.20-fold more frequently than clinical examination and uniquely identifies bone marrow edema, which is the strongest independent predictor of subsequent erosive progression. 6, 2
Critical Pitfalls to Avoid
Do not skip plain radiographs in favor of ultrasound or MRI initially, even though these modalities are more sensitive for inflammation. 1 Plain radiographs remain essential because they:
- Provide permanent, reproducible records for serial comparison 7, 4
- Detect structural damage more reliably than ultrasound in established disease 1
- Are readily available, inexpensive, and immediately interpretable 4
- Can be blinded and randomized for objective assessment 7
Do not image only the hands without the feet. Radiographs of the feet must be included because they often show earlier and more extensive erosive changes than the hands, and omitting them significantly underestimates disease burden. 3
Monitoring Considerations
For established RA, periodic radiographic evaluation of hands and feet should be performed to monitor structural progression, though MRI and ultrasound are more responsive to change at earlier time points. 2 Radiographic damage progresses at a relatively constant rate (mean 8.6 Sharp units per year), with 75% of all damage occurring in the first 5 years. 3, 2
If cervical spine involvement is clinically suspected (neck pain, neurological symptoms), obtain lateral cervical spine radiographs in flexion and neutral positions (strength of recommendation 9.4). 2