POS0038 THE INFLUENCE OF AGE ON THE PREVALENCE OF INFLAMMATORY AND POST-INFLAMMATORY MRI LESIONS IN THE SACROILIAC JOINTS OF PATIENTS WITH AND WITHOUT AXIAL SPONDYLOARTHRITIS

Background: Axial spondyloarthritis (axSpA) is clinically characterized by chronic inflammatory back pain and structural changes in the sacroiliac joint (SIJ) as assessed magnetic resonance imaging (MRI). Several studies have reported high rates of bone marrow edema (BME) suggestive SIJ up to 20% individuals general population <45 years. An update definition a positive MRI axSpA for classification purposes, based on number slices or quadrants showing BME such erosions fat lesions (FL), was recently published ASAS. Objectives: To compare influence age prevalence patients with low diagnosed non-SpA. Methods: MRIs referred differential diagnosis who were finally not experienced rheumatologists, evaluated using semi-coronal STIR T1-weighted sequences. All images scored blinded to, age, sex occurrence BME, FL, ankylosis level SIJ-quadrants (SIJ-Q). Patient groups built decade (until 29, 30-39, 40-49 ≥50 years). Results: A total 309 (175 134 non-SpA) complete sets included analysis. The mean 38.5±11.4 43.4±13.8, 66.9% 35.8% male, CRP 1.6±2.4 1.1±2.1mg/dl median symptom duration 48 60 months, respectively. SIJ-Q significantly higher vs. non-SpA independent group (Table 1). In comparison, exception oldest (≥50 years), FL at least one different between subgroups, while but both increasing age. univariate analysis, only female associated FL. Conclusion: Despite relatively patients, more frequent presence groups. are increasingly found older diagnosis. These data relevant interpretation findings suspicious axSpA. Table 1. Comparison Disclosure Interests: None declared.