Psoriatic arthritis and rheumatoid arthritis: findings in contrast-enhanced MRI.

OBJECTIVE. Our objective was to define typical MRI findings of the wrist and the hand in patients with psoriatic arthritis (PsA) and rheumatoid arthritis (RA). MATERIALS AND METHODS. Eighteen PsA and 21 RA patients with arthralgia of the wrist or hand joints underwent gadolinium-enhanced MRI of the wrist and hand. Two experienced radiologists interpreted abnormalities in consensus with respect to periarticular soft-tissue swelling, synovitis with or without effusion, periostitis, bone edema, bone erosions, bone cysts, and tenosynovitis. The distribution of the abnormalities also was evaluated. RESULTS. Erosions were statistically more frequent in patients with RA (p < 0.05). Periostitis was statistically seen more frequently in patients with PsA (P < 0.05). No statistically significant difference was found in the frequency of synovitis, bone marrow edema, bone cysts, and tenosynovitis between the two groups (p > 0.05). The radiocarpal joint, the midcarpal joints, the carpometacarpal joints, and the metacarpophalangeal joints were significantly affected more frequently in patients with RA than in patients with PsA (p < 0.05), whereas the proximal interphalangeal joints were significantly more frequently affected in patients with PsA (p < 0.05). CONCLUSION. Periostitis and synovitis of the proximal interphalangeal joints are typical MRI findings in patients with PsA, whereas synovitis with erosions of the wrist, the midcarpal joints, the carpometacarpal joints, and the metacarpophalangeal joints are typical findings in patients with RA.