Magnetic resonance imaging and musculoskeletal ultrasonography detect and characterize covert inflammatory arthropathy in systemic sclerosis patients with arthralgia.

OBJECTIVES Arthropathy, particularly synovial inflammation in SSc, is not well characterized. We explored the role of MRI and musculoskeletal ultrasonography (MSUS) in detecting and characterizing synovial inflammation in SSc patients with arthralgia while comparing the two imaging modalities. METHODS Seventeen SSc patients with arthralgia and no overt inflammatory arthritis had a baseline MSUS of their hands. Six months later, 13 unselected patients had a second MSUS and 8 of these 13 patients also had MRI with gadolinium of their most symptomatic hand. RESULTS Of the eight patients undergoing MRI scan, all (100%) patients had synovitis and 88% of patients had tenosynovitis. MRI also showed erosions in 75% of patients. On MSUS, on baseline and second scans, tenosynovitis was seen in 46% and 47% of the patients and synovitis in 6% and 23%, respectively. No erosions were identified. Applying the RAMRIS system (a semi-quantitative MRI scoring system used in RA), the mean values for synovitis, oedema and erosions fell within the range seen in RA. CONCLUSIONS This study demonstrates the presence of a persistent inflammatory, erosive, peripheral arthropathy, similar to that seen in RA, in SSc patients with arthralgia without overt inflammatory joint disease. While both MRI and MSUS are useful in characterizing synovial inflammation in SSc, MRI is clearly more sensitive than MSUS in this setting. Further studies to establish the clinical and radiological musculoskeletal outcomes over time in this group of patients are required in order to identify the appropriate management of arthralgia in SSc.