Background Musculoskeletal ultrasonography (MSKUS) and magnetic resonance imaging (MRI) are known as high sensitive imaging modality toward the patients with rheumatoid arthritis (RA). Especially, the synovial vascularity determined by power Doppler (PD) assessment and osteitis proved by MRI are most important findings to classify as well as reflect the radiographic outcome of RA patients.

Objectives To investigate whether PD assessment of synovial vascularity predict the presence of MRI-proven osteitis in patients with RA.

Methods Twenty-seven RA patients, who fulfilled 2010 RA classification criteria and are naïve to disease-modifying antirheumatic drugs (DMARDs) including biologics or glucocorticoids, are consecutively enrolled in this studyfrom May 2010 through December 2011. Twenty-two joints from each patient including bilateralwrists and finger joints of the 1st – 5th metacarpophalangeal (MCP) joints, the 1st interpharangeal (IP) joint and the 2nd -5th proximal interpharangeal (PIP) joints were examined by both MSKUS and plain MRI. Therefore, a total of 570 joints were investigated in the present study. PD signals were graded on a semi-quantitative manner and MRI-proven osteitis was determined by RAMRI scoring (RAMRIS) technique as previously described. The Cochran-Armitage test was used to test for a trend in the prevalence of osteitis according to PD grade.

Results The mean disease duration, age, DAS28-ESR, prevalence of RF and anti-cyclic citrullinated peptide antibodies (ACPA) at examination were 17 months, 60 years-old, 4.99, 81.5% and 70.4%, respectively. PD grade 1, grade 2 and grade 3 were found in 35 joints, 54 joints and 41 joints, respectively. MRI-proven osteitis was found in 61 joints. A remarkable correlation of the PD grade with the presence of osteitis was demonstrated by the Cochran-Armitage test (p<0.001).

Conclusions The present study may reinforce an importance of PD signals on MSKUS and MRI-proven osteitis to characterize the joint injury in patients with RA.

1. Kawashiri SY, et al. The power Doppler ultrasonography score from 24 synovial sites or 6 simplified synovial sites, including the metacarpophalangeal joints, reflects the clinical disease activity and level of serum biomarkers in patients with rheumatoid arthritis. Rheumatology (Oxford) 2011; 50: 962-5.

2. Tamai M, et al. A prediction rule for disease outcome in patients with undifferentiated arthritis using magnetic resonance imaging of the wrists and finger joints and serologic autoantibodies. Arthritis Rheum. 2009;61:772-8.

Disclosure of Interest None Declared