Background It is vital to establish the diagnosis of rheumatoid arthritis (RA) before radiographic damage and functional disability occurs so that modern potent drugs may be instituted before the “window of opportunity” is closed. To accomplish this, sensitive and specific tools for assessing disease activity and joint damage are needed. Magnetic resonance imaging (MRI) enables more sensitive assessment of both joint inflammation and structural damage than what is achieved by clinical measures and conventional radiography.
Objectives To study the evolution of joint damage - synovitis, tenosynovitis, bone edema and erosions – in patients with RA as visualized by MRI and radiography during the first two years of treatment.
Methods Thirteen patients with RA with disease symptoms less than one year were treated according to clinical practice and followed with MRI and radiography at inclusion (baseline) and after 1, 4, 7, 13, and 25 months. They were treated with 7.5 mg prednisolone daily the first months, thereupon combined with methotrexate for three months and thereafter according to clinical need.
MRI of the dominant wrist and metacarpophalangeal joints were scored for synovitis, tenosynovitis, bone oedema, and erosion using the RA MRI Scoring (RAMRIS) system. Radiographs of the hands were scored with the van der Heijde modified Sharp scores (SHS).
All statistical comparisons between must be interpreted with caution due to the very small patient material.
Results Eight patients were women. At baseline, the mean age was 50 years, disease duration 5 months, DAS28 4.75 and CRP 22. All patients were anti-CCP positive and 11 were rheumatoid factor positive.
At baseline, the mean (SD) RAMRIS score was 27 (18) and after 25 month 22 (10) (NS). The erosion component of the score increased from mean (SD) 3 (6) to 5 (6), p=0.023, while the bone edema score tended to decrease from mean (SD) 7 (12) at baseline to 3 (4) after 25 months (NS). The synovitis and tenosynovitis scores did not change noticeably over time. At baseline, the synovitis and tenosynovitis scores correlated well with the erosion score, rho 0.59, p=0.034 and rho 0.63, p=0.022.
The total SHS score increased during the observation time from mean 1.5 to 4.1 (NS) and the erosion SHS score rose from 3.9 to 4.7 (NS).
Compared with conventional radiography, more erosions were detected by MRI at all points in time, significantly so after 7, 13 and 25 months, p=0.34, p=0.012 and p=0.007.
MRI and SHS erosion scores correlated well at all follow-up visits at 1, 4, 7, 13 and 25 months, rho 0.65, 0.63, 0.70, 0.75 and 0.75.
Conclusions By the use of MRI we could, early in the disease course, show pathologic changes, erosions, bone edema, synovitis and tenosynovitis, which were not visualized by conventional radiography. The data suggest that MRI is superior to conventional radiography in obtaining information on the extent of joint damage in the early phase of RA. This may improve the basis for optimal choice of treatment. The results of this small pilot study needs to be confirmed.
Disclosure of Interest None declared