OP0135 HOW WELL DOES WHOLE BODY MAGNETIC RESONANCE IMAGING AGREE WITH WHOLE BODY ULTRASOUND IN THE ASSESSMENT OF JOINT INFLAMMATION IN RHEUMATOID ARTHRITIS PATIENTS 
Authors: Sin Ngai Ng, Mette Bjørndal Axelsen, Mikkel Ǿstergaard, Iris Eshed, Merete L. Hetland, Jakob Møllenbach Møller, Susanne Juhl Pedersen, Lene Terslev
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Whole body MRI (WBMRI) is a new promising tool for assessing synovitis in the whole body in one session, but is less validated. Ultrasound (US) is another sensitive and well-validated imaging technique that can assess the whole body in one session. <h3>Objectives</h3> To evaluate the agreement between US, WBMRI and clinical assessment of joint inflammation in rheumatoid arthritis (RA) patients on joint and patient level. <h3>Methods</h3> US, WBMRI and clinical assessment for tender joints (TJ) and swollen joints (SwJ) were performed in 19 RA patients (90% Women, median age 55 (26-73), diseases duration 5.5 years (1-42), SwJ(28) 5 (1-13), TJ(28) 7 (2-24) and DAS28-CRP 4.66 (3.48 -6.66))) fulfilling ACR 1987 criteria for RA. The 28 conventional joints, bilateral ankles and MTP 1-5 were assessed by WBMRI and US. Joint inflammation by US was graded 0-3 on both B-mode and colour Doppler (CD), and subsequently converted to +/- by defining US synovitis as B mode &gt;2 or CD &gt;1, and scored for individual joint. For WBMRI, joint inflammation was defined in two ways; 1) as presence of synovitis and/or osteitis, 2) as the presence of synovitis only. The total inflammatory burden was established as sum scores for the 28 conventional joints for US (US28) and for 26 joints (WBMRI26) for WMBRI - same 28 joints except elbows (due to poor image quality). The max score of a joint in US and WBMRI including osteitis was 2, while WMBRI excluding osteitis was 1. The agreement between the clinical joint assessment, US and WBMRI for joint inflammation was calculated with Cohen's kappa (κ). The correlations between US28, WBMRI26 and DAS28-CRP were calculated by Spearman correlation coefficient (rho). <h3>Results</h3> When considering joint inflammation by WBMRI as synovitis and/or osteitis, US28 for synovitis and WBMRI26 sum scores showed good correlation rho= 0.72 (p=0.003) (Fig. 1), whereas US28 and WBMRI26 did not correlate with DAS28 CRP (rho=-0.26, p=0.28; rho=0.20, p=0.47 respectively). Moderate-good agreement was found between US and WBMRI in wrists and MCP 1, 2 and 5(κ= 0.42–0.62) but poor in other joints (κ &lt; 0.37). By comparing WBMRI synovitis (excluding osteitis) with US synovitis, US28 and WBMRI26 sum scores showed weakened correlation rho= 0.46 (p=0.049) (Fig. 2), and without correlation between WBMRI26 and DAS28 CRP (rho=-0.07, p=0.78). At joint level, moderate-good agreement was found between US and WBMRI in wrists, MCP 2 and 5, and PIP 5(κ= 0.41–0.62) but poor in other joints (κ &lt; 0.37). Agreement between US and clinical joint tenderness was poor (all κ&lt;0.31; except κ=0.42 for wrist), but better between US and clinical swelling for shoulders, elbows, MCP1 and PIP5 (κ=0.42–0.66) while &lt;0.36 for other joints. Agreement between WBMRI and clinical joint swelling or tenderness showed κ&lt;0.38 in all joints irrespective of counting osteitis as one of the features or not. <h3>Conclusion</h3> WBMRI and US sum scores of joint inflammation showed good correlation in RA patients for the overall inflammatory burden. The agreement at joint level was variable. <h3> Disclosure of Interests:&nbsp;</h3> Sin Ngai Ng: None declared, Mette Bjørndal Axelsen: None declared, 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, Iris Eshed: None declared, Merete L. Hetland Grant/research support from: BMS, MSD, AbbVie, Roche, Novartis, Biogen, Pfizer, Consultant for: Eli Lilly, Speakers bureau: Orion Pharma, Biogen, Pfizer, CellTrion, Merck, Samsung Bioepis, Jakob Møllenbach Møller: None declared, Susanne Juhl Pedersen: None declared, Lene Terslev Speakers bureau: Speakers fee from : Roche, Novartis, Pfizer, MSD, BMS, Celgene