LAUSR

OBJECTIVES Nasal, paranasal sinus and mucosal disorders are common symptoms in autoimmune rheumatic diseases. Soft tissue changes and fluid accumulation in the osteomeatal complexes and paranasal sinuses manifest as opaqueness on radiological images which can be assessed using visual scoring and computational methods on CT scans but their results do not always correlate. Using magnetic resonance imaging (MRI), we investigate the applicability of different image analysis methods in systemic lupus erythematosus (SLE). METHODS We assessed paranasal sinus opaqueness on MRI from 51 SLE patients, using three visual scoring systems and expert-delineated computational volumes, and examined their association with markers of disease activity, inflammation, endothelial dysfunction, and common small vessel disease (SVD) indicators, adjusting for age and sex-at-birth. RESULTS The average paranasal sinus volume occupation was 4.55 ± 6.47% (median (IQR)=0.67 (0.25-2.65) ml), mainly in the maxillary and ethmoid sinuses. It was highly correlated with Lund-Mackay (LM) scores modified at 50% opaqueness cut-off (Spearman's ρ: 0.71 maxillary and 0.618 ethmoids, P < 0.001 in all), and with more granular variations of the LM system. The modified LM scores were associated with SVD scores (0: B = 5.078, SE = 1.69, P = 0.0026; 2: B=-0.066, SE = 0.023, P = 0.0045), and disease activity (anti-dsDNA: B = 4.59, SE = 2.22, P= 0.045, SLEDAI 3 to 7: 2.86