Defining active sacroiliitis on MRI for classification of axial spondyloarthritis: update by the ASAS MRI working group: update by the ASAS MRI working group

Robert G. W. Lambert, Pauline A. C. Bakker, Désirée van der Heijde, Ulrich Weber, Martin Rudwaleit, K. G. Hermann, Joachim Sieper, Xenofon Baraliakos, Alex Bennett, Jürgen Braun, Rubén Burgos-Vargas, Maxime Dougados, Susanne Juhl Pedersen, Anne Grethe Jurik, Walter P. Maksymowych, Helena Marzo-Ortega, Mikkel Østergaard, Denis Poddubnyy, Monique Reijnierse, Filip van den BoschIrene van der Horst-Bruinsma, Robert Landewé

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To review and update the existing definition of a positive MRI for classification of axial spondyloarthritis (SpA). The Assessment in SpondyloArthritis International Society (ASAS) MRI working group conducted a consensus exercise to review the definition of a positive MRI for inclusion in the ASAS classification criteria of axial SpA. Existing definitions and new data relevant to the MRI diagnosis and classification of sacroiliitis and spondylitis in axial SpA, published since the ASAS definition first appeared in print in 2009, were reviewed and discussed. The precise wording of the existing definition was examined in detail and the data and a draft proposal were presented to and voted on by the ASAS membership. The clear presence of bone marrow oedema on MRI in subchondral bone is still considered to be the defining observation that determines the presence of active sacroiliitis. Structural damage lesions seen on MRI may contribute to a decision by the observer that inflammatory lesions are genuinely due to SpA but are not required to meet the definition. The existing definition was clarified adding guidelines and images to assist in the application of the definition. The definition of a positive MRI for classification of axial SpA should continue to primarily depend on the imaging features of 'active sacroiliitis' until more data are available regarding MRI features of structural damage in the sacroiliac joint and MRI features in the spine and their utility when used for classification purposes
Original languageEnglish
Pages (from-to)1958-1963
Number of pages6
JournalAnnals of the rheumatic diseases
Issue number11
Publication statusPublished - Nov 2016

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