Remission by imaging in rheumatoid arthritis: should this be the ultimate goal?

Remission is often selected as the 'treat to target'. There is a plea to include imaging. Imaging remission can apply to structural damage and/or inflammation. For structural damage, radiographs are mostly used. A definition is needed which could be either strict, with no progression occurring, or which takes measurement error into account and uses the smallest detectable change. Mostly imaging remission refers to inflammation as assessed by ultrasound or MRI. The reason for arguing that imaging remission should be included for inflammation is that inflammation may still be present in patients who are in clinical remission. The level of inflammation depends on the clinical remission definition that is used. Bone marrow oedema is the feature that is most predictive of radiographic progression. However, before imaging remission can be implemented as a recommendation, a definition of remission by imaging needs to be established. A choice has to be made about the level of inflammation that can be tolerated and how this needs to be assessed (which imaging method, which feature, which joints, which cut-off point). Moreover, imaging remission should only be selected as a target if it can be proved that it can be treated and that the outcome of the patients will be improved by trying to achieve imaging remission in addition to clinical remission. This proof is not yet available, and too many unanswered questions remain to recommend including imaging remission of inflammation in a definition of remission.