AB1183 ULTRASOUND POWER DOPPLER AND GREY-SCALE JOINT INFLAMMATION: WHAT DO THEY REVEAL ABOUT RHEUMATOID ARTHRITIS?
Authors: York Kiat Tan, LI Huihua, John Carson Allen, Julian Thumboo
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Grey-scale (GS) and Power Doppler (PD) imaging are routinely performed when assessing rheumatoid arthritis (RA) joint inflammation using ultrasound (US). While PD vascularity is often regarded as an US feature of more active joint inflammation, the true clinical significance of GS joint inflammation in RA is less understood. <h3>Objectives</h3> To gain further insight into US PD and GS joint Inflammation through studying their relationship with two distinct, yet important outcome measures: (i) DAS28 – a disease activity measure and (ii) US-detected erosion - a structural joint damage measure. <h3>Methods</h3> In this cross sectional study, US PD and GS joint inflammation were graded semi-quantitatively (0-3), while bone erosion(s) was scored dichotomously (1=yes/0=no) at each joint recess. At the patient level, PD and GS scores were correlated with DAS28 and US erosion scores respectively using Pearson's correlation coefficient, while linear regression was used to characterize the relationship between variables. <h3>Results</h3> 1080 joints and 1800 joint recesses from bilateral elbows, wrists, MCPJs, thumbs' IPJs, PIPJs, ankles and MTPJs were scanned in 30 adult RA patients (baseline characteristics: 76.7% Chinese; 93.3% female; mean (SD) DAS28, 3.58 (1.20); mean (SD) disease duration, 70.3 (61.2) months). PD scores were correlated (r=0.46, P&lt;0.0104) with DAS28 but not with US erosion scores. GS scores were correlated (r= 0.64, P&lt;0.0001) with US erosion scores but not with DAS28 (table 1). Scatter plots for these variables are presented in Figure 1. Results of simple linear regressions showing PD as a predictor of DAS28 (coefficient (95% CI), 0.167 (0.048, 0.286); P=0.0104) and GS as a predictor of US erosion (coefficient (95% CI), 0.223 (0.125, 0.322); P=0.0001) are summarized in table 2. <h3>Conclusion</h3> US PD and GS joint inflammation in RA were characterized using disease activity and structural joint damage outcome measures. PD joint inflammation is associated with disease activity and has moderate correlation with DAS28. In contrast, GS joint inflammation is associated with structural joint damage and has strong correlation with US-detected erosion. <h3>References</h3> [1] Backhaus M, et al. Guidelines for musculoskeletal ultrasound in rheumatology. Ann Rheum Dis 2001;60:641–9. [2] Backhaus M, et al. Evaluation of a novel 7-joint ultrasound score in daily rheumatologic practice: a pilot project. Arthritis Rheum 2009;61:1194-201. [3] Hammer HB, et al. Examination of intra and interrater reliability with a new ultrasonographic reference atlas for scoring of synovitis in patients with rheumatoid arthritis. Ann Rheum Dis 2011;70:1995–8. [4] Wakefield RJ, et al. Musculoskeletal ultrasound including definitions for ultrasonographic pathology. Journal of Rheumatology 2005;32(12):2485–7. Statistically significant: * p&lt;0.05; *** p&lt;0.001 Statistically significant: * p&lt;0.05; *** p&lt;0.001 <h3>Disclosure of Interests</h3> None declared