POS1391 MEASURING SUBCLINICAL INFLAMMATION IN HAND AND FOREFOOT IN PATIENTS WITH ARTHRALGIA USING 1.5T OR 3.0T MRI: DOES FIELD STRENGTH MATTER?

Background: Magnetic resonance imaging (MRI) of small joints sensitively detects inflammation. MRI-detected subclinical inflammation, and tenosynovitis in particular, has been shown predictive for RA development patients with arthralgia. These scientific data are mostly acquired on 1.0T-1.5T MRI scanners. However, 3.0T is nowadays increasingly used practice. Evidence the comparability these field strengths scarce it never studied arthralgia where inflammation subtle. Moreover, comparisons included tenosynovitis, which is, all features, strongest predictor progression to RA. Objectives: To determine if there a difference between 1.5T detecting patients. Methods: 2968 locations (joints, bones or tendon sheaths) hands forefeet 28 were imaged both MRI. Two independent readers scored erosions, osteitis, synovitis (according RAMRIS) (as described by Haavaardsholm et al.). Scores also summed as total (osteitis, tenosynovitis) RAMRIS (erosions, scores. Interreader reliability (comparing readers) strength agreement 3.0T) was assessed interclass correlation coefficients (ICCs). Next, after dichotomization into presence absence Analyses performed patient- location-level. Results: ICCs excellent (>0.90). Comparing 1.5 revealed 0.90 (95% confidence interval 0.78-0.95) score (0.78-0.95) score. individual features were: tenosynovitis: 0.87 (0.74-0.94), 0.65 (0.24-0.84) osteitis 0.96 (0.91-0.98). The dichotomized scores 83% 89% Of highest (89%). location- level showed similar results. Conclusion: Agreement good excellent, particular tenosynovitis. This suggests that evidence power patients, obtained 1.5T, can be generalized when this would diagnostic purposes daily Disclosure Interests: None declared