Magnetic resonance imaging (MRI) allows objective assessment of both inflammation (disease activity) and damage in arthritic diseases, such as rheumatoid arthritis (RA), psoriatic arthritis (PsA) and osteoarthritis (OA). MRI provides important insights into how these diseases progress and very importantly for OMERACT it provides objective measures of response to treatments, as clinical examination findings of tender and swollen joints can be quite unreliable.

MRI is therefore now frequently used as an outcome measure across rheumatology clinical trials. The OMERACT MRI in Arthritis Working Group has been instrumental in this. The group has developed and validated the OMERACT rheumatoid arthritis MRI score (RAMRIS), evaluating the key features of activity and damage in the joints; this method is now the standard used in RA trials using MRI. Furthermore, the group has developed and validated a psoriatic arthritis (PsA) MRI scoring method (PsAMRIS), a hand osteoarthritis (OA) MRI scoring system (HOAMRIS), including a dedicated system for the thumb base (TOMS), a whole-body MRI scoring system allowing assessment of all peripheral joints and entheses (WBMRI WIPE), an enthesitis scoring system (HEMRIS) and a digital overlay-based scoring system of MRI lesions in OA of the hips and knees (HIMRISS and KIMRISS).

Since OMERACT in 2018, the group has continued its work within MRI of enthesitis and whole-body MRI MRI in spondyloarthritis and psoriatic arthritis and within osteoarthritis of the hand, hip and knee. Data from these activities will be presented at OMERACT in Colorado Springs, USA, in April 2020