SP0097 MRI OF ENTHESITIS: HOW TO DO AND WHAT TO LOOK FOR
Authors: Mikkel Ǿstergaard
Journal: Annals of the Rheumatic Diseases (2019)

<h3></h3> Enthesitis, inflammation at the insertion site of tendon, ligament or joint capsule into bone, is considered a key pathological feature in spondyloarthritis (SpA) and psoriatic arthritis (PsA)[1]. Compared to conventional assessment of enthesitis using clinical scores, MRI detects both soft tissue and intra-osseous abnormalities in active enthesitis, potentially aiding early diagnosis and outcome measurement in SpA and PsA[2]. With the advent of treat-to-target concept and novel therapies, objective and sensitive monitoring of response of enthesitis to therapy is desirable, and a validated MRI scoring system would be a useful adjunct to clinical practice as well as providing additional information as an outcome measure in clinical trials. The Outcome Measures in Rheumatology (OMERACT) MRI in Arthritis Working Group recently undertook a systematic literature review (SLR) aiming to critically evaluate the published literature for available methods of evaluating enthesitis using MRI in SpA and PsA patients, describing the MRI variables, definitions and scoring systems used to diagnose and monitor enthesitis)[3]. Considerable limitations was found regarding standardisation of MRI enthesitis definitions across studies and validity of available semi-quantitative scores as outcome measures. The findings suggested a need for reliable and validated MRI scoring system for enthesitis. Subsequently, The OMERACT MRI group developed consensus definitions of key pathologies and three heel enthesitis multi-reader scoring exercises were done, separated by discussion, training and calibration [4]. In a final exercise, median pairwise single-measures intra-class correlation coefficients (ICCs; patient-level) for entheseal inflammation status/change scores were 0.83/0.82 for all readers. For radiologists and selected rheumatologists ICCs were 0.91/0.84 and quadratic-weighted kappas (lesion-level) 0.57-0.91/0.45-0.81. It was concluded that the proposed definitions and heel enthesitis scoring system (OMERACT HEMRIS) are reliable among trained readers and promising for clinical trials [4]. This talk will briefly review the evidence behind the use of MRI for diagnosis and monitoring enthesitis, describe the recently developed OMERACT consensus definitions of key pathologies, and provide examples of these pathologies, aiming for the attendees to learn to be able to recognize them. Finally, an interactive quiz using cases for audience review will be undertaken to test this ability. <h3>References:</h3> [1] Eshed I, Bollow M, McGonagle DG, Tan AL, Althoff CE, Asbach P, Hermann KG. MRI of enthesitis of the appendicular skeleton in spondyloarthritis. Ann Rheum Dis 2007;66:1553-9. [2] Poggenborg RP, Eshed I, Østergaard M, Sorensen IJ, Moller JM, Madsen OR, Pedersen SJ. Enthesitis in patients with psoriatic arthritis, axial spondyloarthritis and healthy subjects assessed by 'head-to-toe" whole-body MRI and clinical examination. Ann Rheum Dis 2015;74:823-9. [3] Mathew AJ, Krabbe S, Kirubakaran R, Barr AJ, Conaghan PG, Bird P, Østergaard M. Utility of Magnetic Resonance Imaging in Diagnosis and Monitoring Enthesitis in Patients with Spondyloarthritis: An OMERACT Systematic Literature Review. J Rheumatol 2019. [4] Mathew AJ, Krabbe S, Eshed I, Gandjbakhch F, Bird P, Pedersen SJ, Stoenoiu MS, Foltz V, Glinatsi D, Lambert RG, Hermann KGA, Maksymowych WP, Haugen IK, Jaremko JL, Poggenborg RP, Paschke J, Laredo JD, Carron P, Conaghan PG, Østergaard M. The OMERACT MRI in Enthesitis Initiative: Definitions of Key Pathologies, Suggested MRI Sequences and Novel Heel Enthesitis Scoring System (HEMRIS). J Rheumatol 2019. <h3>Disclosure of Interests:</h3> Mikkel Ǿstergaard Grant/research support from: Abbvie, Celgene, Centocor, Merck, Novartis, Consultant for: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB, Speakers bureau: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB