LAUSR

Background: Using high-field MRI to differ morphologically between OA and RA. Objectives: To evaluate the value of morphological and biochemical, contrast-agent free high-field (3 Tesla) MRI of the radiocarpal cartilage to differ between osteoarthritis (OA) and rheumatoid arthritis (RA). Methods: The group consisted of 47 subjects, who were examined during the period from October 2016 to December 2017. The clinical dominant hand of 11 patients suffering from early rheumatoid arthritis (RA) (German ArthroMark cohort, Ø 52.8years; min: 32; max 74), seropositive (ACPA and/or RF), disease duration < 6 months (range 2 –23 weeks)), 10 with osteoarthritis (OA) (Ø 48.55 ± 15.23 years, min: 34 years, max: 68 years, disease duration Ø 6 years ± 8.29) and 26 healthy volunteers (Ø 46.55 ± 17.55 years, min: 20 years, max: 79 years) were examined with a 3T MRI scanner, prospectively. Morphological and biochemical assessment of radiocarpal cartilage was performed using DESS, TrueFISP and T2* images. Results: Morphological sequences demonstrated significantly higher cartilage damage in RA and OA compared to healthy controls (DESS: p = 0.01, p = 0.0004; TrueFISP: p = 0.02, p = 0.0001), while there was no significant difference between RA and OA patients. With biochemical MRI using T2* imaging, patients with OA showed higher cartilage integrity compared to patients with RA (p = 0.01). Conclusion: Morphological and biochemical MRI of radiocarpal cartilage could be helpful to differentiate between RA and OA patients. Both, RA and OA, are associated with cartilage damage measured by morphological MRI of the hand. Hence, OA was associated with more loss of cartilage integrity compared to RA using biochemical MRI, whereby only early RA patients were analyzed in this first evaluation. Non-contrast-agent morphological and biochemical MRI could be a non-invasive tool to investigate cartilage integrity in RA and OA patients and could help to differ disease pattern in the future. Acknowledgement: We would like to thank Erika Rädisch for the assistance in receiving the MRI scans. Disclosure of Interests: Philipp Sewerin: None declared, Lino Sawicki: None declared, Christoph Schleich: None declared, Daniel Abrar: None declared, Matthias Schneider Grant/research support from: GlaxoSmithKline and UCB Pharma for performing the LuLa-study., Speakers bureau: Chugai, Stefan Vordenbäumen: None declared, Benedikt Ostendorf: None declared