Dynamic MRI of the Wrist in Early Arthritis May Predict its outcome
1. [2008] [FRI0438] DYNAMIC MRI OF THE WRIST IN EARLY ARTHRITIS MAY PREDICT ITS OUTCOME
G. Zampogna1, M. Parodi1, M. D'Auria2, G. Minetti2, D. Schettini2, G. Garlaschi2, E. Silvestri2, M.A. Cimmino1 1Clinica Reumatologica; 2DI.ME.S, Università, Genova, Italy
Background: Different methods have been proposed to evaluate the long-term outcome in patients with early arthritis. These include combinations of clinical and laboratory parameters, health assessment scales, conventional radiography, and MRI.
Objectives: To evaluate if dynamic MRI performed at presentation in patients with early arthritis can predict its outcome.
Methods: 39 patients with early arthritis of less than 10 months duration (median 4 months, range 1-10 months), involving at least one wrist, were studied. They were followed for a medain period of 39 months (range 12-84 months) with clinical visits and laboratory investigations every 3 months. At every follow up visit, DAS, HAQ, Ritchie Index, and fulfilment of ACR and Visser et al. criteria (VC) (1) were assessed. ESR, IgM rheumatoid factor, and anti CCP antibodies were also evaluated. Immunosoppressive treatment at the time of the last visit was also considered as negative end point. MRI was performed with a low-field (0.2T), extremity-dedicated machine (Artoscan, Esaote, Genova, Italy) equipped with a permanent magnet and with a dedicated hand and wrist coil of 13 cm in diameter. Slice thickness was 5 mm and interslice gap was 0 mm. The sequence used was a Spin Echo (TR/TE=100/16 ms, matrix= 160x128, FOV= 150x150). After positioning of the wrist in the gantry, the first image was acquired. Then, an intravenous bolus injection of 0.2 ml/kg of Gd-DTPA (Omniscan, Schering, Germany) was performed in 30'' through a 21 mm butterfly needle into a cubital vein. Twenty consecutive fast images of 3 slices of the wrist, the first of which was positioned tangential to the radius, were repeated every 18'' thereafter. The rate of enhancement was calculated as delta on a small region of interest of synovial membrane of approximately 25 mm2 positioned in the area of highest visual enhancement. The enhancement ratio was calculated both as rate of early enhancement (REE) per second during the first 55'' and as relative enhancement (RE) at t seconds. The REE shows the slope of the curve of contrast uptake and is steeper if inflammation is higher. The RE indicates the steady state of enhancement.
Results: In our cohort of patients, mean REE and RE were 1.1±0.8 and 83.2±52.2, respectively. These values were significantly higher than those observed in a historical cohort of 36 patients with active rheumatoid arthritis (REE 1.9±0.6, p<0.0001 and RE 140.5±36.0, p<0.0001). No differences were observed for REE and RE according to the final diagnosis at the end of follow-up [RA (n=12), psoriatic arthritis (n=3), connective tissue disease (n=3), other inflammatory conditions (n=12), or complete remission without treatment (n=9)]. In multivariate analysis, a final diagnosis of RA was not predicted by either VC or REE and RE; fulfilment of ACR criteria for RA at any time during follow up was predicted only by VC (p=0.03); complete remission at the end of follow-up was predicted only by a low RE (p=0.05); and the need for immunosoppressive treatment at the end of follow-up was predicted by both VC (p=0.03) and high REE (p=0.02).
Conclusion: Dynamic MRI may be used to predict the outcome of early arthritis and is comparable to VC.
References: 1. Visser H, et al. How to diagnose rheumatoid arthritis early. Arthritis Rheum 2002; 46: 357-65.
2. Cimmino MA, et al. Dynamic gadolinium-enhanced magnetic resonance imaging of the wrist in patients with rheumatoid arthritis can discriminate active from inactive disease. Arthritis Rheum. 2003; 48: 1207-13.
Ann Rheum Dis 2008;67(Suppl II):420